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1

NONLINEAR ANALYSIS OF BONDED COMPOSITE SINGLE-LAP JOINTS  

Microsoft Academic Search

Nomenclature This study presents a semi-analytical solution method to analyze the geometrically nonlinear response of bonded composite single-lap joints with tapered adherend edges under uniaxial tension. The solution method provides the transverse shear and normal stresses in the adhesive and in-plane stress resultants and bending moments in the adherends. The method utilizes the principle of virtual work in conjunction with

E. Oterkus; A. Barut; E. Madenci; S. S. Smeltzer; D. R. Ambur

2

Analysis of Adhesively Bonded Single Lap Joint in Laminated Frp Composites Subjected to Transverse Load  

Microsoft Academic Search

The present investigation deals with the static analysis of adhesively bonded single lap joint in laminated FRP composites using three-dimensional theory of elasticity based finite element method. The finite element model is validated with the available results in the literature for the longitudinal loading of a single lap joint (SLJ) made of specially orthotropic laminates and is extended for the

M. Venkateswara Rao; K. Mohana Rao; V. Rama; Chandra Raju; V. Bala Krishna Murthy; V. V. Sridhara Raju

3

The Strength of Bolted and Bonded Single-Lapped Composite Joints in Tension  

Microsoft Academic Search

This work is primarily concerned with a failure analysis of single-lapped bolted and bonded mixed-composite joints, representing practical situations, both in terms of experimental data and theoretical appreciation. Two kinds of stacking sequences in adherends are tested: quasi-isotropic and cross-ply. The adhesives include thermal-setting and thermal-plastic types. The bolts used to clamp the bonded joints are made of 304 stainless

Wei-Hwang Lin; Ming-Hwa R. Jen

1999-01-01

4

Shear Strength of Single Lap Joint Aluminium-Thermoplastic Natural Rubber (Al-TPNR) Laminated Composite  

NASA Astrophysics Data System (ADS)

In this work, we studied the effect of surface treatment on the aluminium surface and a coupling agent to improve adhesion between aluminium with organic polymer. Thermoplastic natural rubber (TPNR) matrix was prepared by melt blending of natural rubber (NR), liquid natural rubber (LNR) compatibilizer, linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH). The PEgMAH concentration used was varied from 0% - 25%. In addition, the aluminium surface was pre-treated with 3-glycidoxy propyl trimethoxy silane (3-GPS) to enhance the mechanical properties of laminated composite. It was found that the shear strength of single lap joint Al-TPNR laminated composite showing an increasing trend as a function of PE-g-MAH contents for the 3-GPS surface treated aluminium. Moreover, the scanning electron microscope (SEM) revealed that the strength improvement was associated with the chemical state of the compound involved.

Muzakkar, M. Z.; Ahmad, S.; Yarmo, M. A.; Jalar, A.; Bijarimi, M.

2013-04-01

5

Three-Dimensional Finite Element Analysis of Adhesively Bonded Single Lap Joints in Laminated FRP Composites Subjected to Combined Loading with CC End Conditions  

Microsoft Academic Search

The present investigation deals with the thermo-elastic analysis of adhesively bonded single lap joint in laminated FRP composites using three- dimensional theory of elasticity based finite element method. The finite element model is validated with the available results in the literature for the longitudinal loading of a single lap joint (SLJ) made of specially orthotropic laminates and is extended for

M. Venkateswara Rao; K. Mohana Rao; V. Rama; Chandra Raju; V. Bala Krishna Murthy; V. V. Sridhara Raju

6

Fatigue strength of a single lap joint SPR-bonded  

NASA Astrophysics Data System (ADS)

In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints. The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

di Franco, G.; Fratini, L.; Pasta, A.

2011-05-01

7

Creep Stress Redistribution of Single-Lap Weldbonded Joint  

NASA Astrophysics Data System (ADS)

Weldbonding is a new joining technique that combines the spot welding with the adhesive bonding. It has found more and more applications in recent years because of its unique advantages. However, researches on the new technique are few especially on the long-term stress and strength of weldbonded structures. In the present paper, three-dimensional viscoplastic finite element analyses (FEA) of a single-lap weldbonded joint are conducted to investigate the stress redistribution. The results show that stresses increase obviously near the interface between the adhesive and the weld spot with the creep of adhesive. The adhesive tends to distribute its stresses more uniformly and transfer some loads to the weld spot. The stress concentration factor of weldbonded joint is significantly lower than that of the direct spot-weld in connection. The simulations illustrate that increasing of creep parameter will enhance the maximum stress level in the weld spot.

Yin, Yong; Chen, Jian-Jun; Tu, Shan-Tung

2005-01-01

8

Elastoplastic Stress Analysis of an Adhesively Bonded Single Lap Joint Subjected to a Bending Moment  

Microsoft Academic Search

In this study, an elasto-plastic stress analysis of the single lap joint (SLJ) under bending moment was investigated. The single lap joint consisted of Etial 5 ½ H as the adherends bonded by Araldite 2011 as the adhesive. Since the failure criterion of the SLJ is based on the uniaxial tensile properties of adhesive and adherends, the uniaxial tensile tests

M. Kemal APALAK; Aysel ENGIN

9

Influence of harsh environmental conditions on CFRP-aluminum single lap joints  

Microsoft Academic Search

Purpose – The objective of this paper is to investigate the influence of harsh environmental conditions on the fundamental failure mechanisms of carbon fiber reinforced plastic (CFRP)-aluminum single lap single-bolted joints under tensile loading. Design\\/methodology\\/approach – CFRP-aluminum single lap joints were aged under extremely hot (60°C), hot and humid (60°C, 95%RH), and freezing cold (?51°C) environments and tensile-tested to measure

Luis Breziner; Parsaoran Hutapea

2008-01-01

10

Effects of adhesive fillers on the strength of tubular single lap adhesive joints  

Microsoft Academic Search

When an adhesively bonded joint is exposed to a high environmental temperature, the tensile load capability of the adhesively bonded joint decreases because the elastic modulus and failure strength of the adhesive decrease. In this paper, the elastic modulus and failure strength of the adhesive as well as the tensile load capability of the tubular single lap adhesively bonded joint

Dai Gil Lee; Jin Kook Kim; Durk Hyun Cho

1999-01-01

11

Effect of metal as part of fillet on the tensile shear strength of adhesively bonded single lap joints  

Microsoft Academic Search

The effect of fillet containing metallic components on the strength of adhesively bonded single lap joints has been undertaken by alternating the shape and size of metallic components as a part of fillet or whole fillet at the end of the joints. Mild carbon steel and epoxy structural adhesive were used to prepare single lap-shear joints. Three types of steel

Min You; Yong Zheng; Xiao-Ling Zheng; Wen-Jun Liu

2003-01-01

12

Influence of adhesive spew in bonded single-lap joints  

Microsoft Academic Search

Adhesively bonded lap joints involve dissimilar material junctions and sharp changes in geometry, possibly leading to premature failure. Although the finite element method is well suited to model the bonded lap joints, traditional finite elements are incapable of correctly resolving the stress state at junctions of dissimilar materials because of the unbounded nature of the stresses. In order to facilitate

B. Kilic; E. Madenci; D. R. Ambur

2006-01-01

13

Characterisation of GFRP surfaces amenable for bonding and their effect on the strength of co-cured vacuum resin infused single lap joints  

Microsoft Academic Search

The choice of a fabrication method is of primary importance in order to optimise and control the performance of composite materials. This becomes increasingly crucial when the fabrication method itself becomes in parallel an adhesive bonding co-cure technique. In this paper, the manufacturing process of the vacuum resin infusion jointing is introduced and specimens of co-cured single lap joints are

D. Tzetzis

2012-01-01

14

Stress analysis and strength evaluation of single-lap adhesive joints combined with rivets under external bending moments  

Microsoft Academic Search

Stress analysis and strength evaluation of single-lap adhesive joints combined with rivets (i.e. single-lap riveted-adhesive joints) under external bending moments are investigated by threedimensional finite element analysis (FEA). In this analysis, the effects of the ratio of Young's moduli of the rivets to that of the adherends and the initial tightening force produced in the process of fitting the rivets

Jiemin Liu; Toshiyuki Sawa

2001-01-01

15

Stress-Strain Analysis of Single-Lap Tensile Loaded Adhesive Joints  

NASA Astrophysics Data System (ADS)

Both, experimental investigation and finite element analysis of single-lap adhesive joints subjected to tension have been done to find out an optimal overlap length. As the adherend material aluminum was considered with the two component high-strength engineering adhesive for the bonding of the layers. The thickness of the sheet metal layer was 1,95 mm, while adhesive was 0,15 mm thick. The width of all thin plates was 30 mm, but the overlap length varied as 15, 20, 30, 40 and 60 mm. Real mechanical properties of all materials in the joint have been determined experimentally. Obtained results proved that the overlap length affects directly the joint tensile strength, where an optimum value of overlap length can be defined. Finite element analysis of stress and strain fields could help to determine the moment when the crack initiates at the joint overlap end. In such a manner, complex mechanisms of failure of adhesive joints could be better understood.

Raos, Pero; Kozak, Dražan; Luci?, Mirjana

2007-05-01

16

Stress-Strain Analysis of Single-Lap Tensile Loaded Adhesive Joints  

SciTech Connect

Both, experimental investigation and finite element analysis of single-lap adhesive joints subjected to tension have been done to find out an optimal overlap length. As the adherend material aluminum was considered with the two component high-strength engineering adhesive for the bonding of the layers. The thickness of the sheet metal layer was 1,95 mm, while adhesive was 0,15 mm thick. The width of all thin plates was 30 mm, but the overlap length varied as 15, 20, 30, 40 and 60 mm. Real mechanical properties of all materials in the joint have been determined experimentally. Obtained results proved that the overlap length affects directly the joint tensile strength, where an optimum value of overlap length can be defined. Finite element analysis of stress and strain fields could help to determine the moment when the crack initiates at the joint overlap end. In such a manner, complex mechanisms of failure of adhesive joints could be better understood.

Raos, Pero; Kozak, Drazan; Lucic, Mirjana [University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Trg Ivane Brlic-Mazuranic 2, HR-35000 Slavonski Brod (Croatia)

2007-05-17

17

Stress analysis and strength evaluation of single-lap band adhesive joints of dissimilar adherends subjected to external bending moments  

Microsoft Academic Search

Single-lap band adhesive joints of dissimilar adherends subjected to external bending moments are analyzed as a four-body contact problem using a two-dimensional theory of elasticity (plane strain state). In the analysis, the upper and lower adherends and the adhesive which are bonded in two regions are replaced by finite strips. In the numerical calculations, the effects of the ratio of

Jiemin Liu; Toshiyuki Sawa

2000-01-01

18

Stress analysis and strength evaluation of single-lap band adhesive joints subjected to external bending moments  

Microsoft Academic Search

Single-lap band adhesive joints of similar adherends subjected to external bending moments are analyzed as a four-body contact problem using a two-dimensional theory of elasticity (plain strain state). In the analysis, the upper and lower adherends and the adhesives which are bonded at two regions are replaced by finite strips. In the numerical calculations, the effects of the ratio of

Jiemin Liu; Toshiyuki Sawa

1999-01-01

19

Reinforcing an aluminum\\/GFRP co-cured single lap joint using inter-adherend fiber  

Microsoft Academic Search

Methods to increase the strength of co-cured joints are highly sought after for metal\\/composite hybrid structures. The present study proposes a reinforcing method for aluminum\\/glass fiber-reinforced polymer co-cured composites using inter-adherend (IA) fiber that penetrates into the composite and holes in the metal adherend. The IA fiber performs as a bridge and suppresses crack propagation in the lap joints. Static

Ryosuke Matsuzaki; Motoko Shibata; Akira Todoroki

2008-01-01

20

Thermal characteristics of tubular single lap adhesive joints under axial loads  

Microsoft Academic Search

When an adhesive joint is exposed to high environmental temperature, the tensile load capability of the adhesive joint decreases because both the elastic modulus and failure strength of the adhesive decrease. The thermo-mechanical properties of a structural adhesive can be improved by addition of fillers to the adhesive. In this paper, the elastic modulus and failure strength of adhesives as

Jin Kook Kim; Dai Gil Lee

2001-01-01

21

In vitro study on the fatigue limit of single-lap joints.  

PubMed

Lasting adhesion between attachment and tooth is an essential prerequisite for all adhesive techniques in dentistry. However, the maximum static fatigue load is only one material-related parameter for the quality of this adhesion. Another parameter is the dynamic loading capacity of a bonded joint, which was determined in the present study for Dual adhesive resin by means of fatigue testing. This revealed a significant correlation between the recorded static and dynamic fatigue load and the gap width, which varied between 0.01 mm, 0.15 mm and 0.5 mm in the experimental setup. At 18.8 MPa, the median gap width of 0.15 mm yielded the highest static resistance, with a dynamic resistance 15% below this figure. Both the smaller and the larger gap showed significantly lower static fracture strengths (0.01 mm: 13.6 MPa; 0.5 mm: 13.7 MPa), whereas a dynamic load on the 0.01 mm bond, in contrast to the 0.5 mm bond, led to only a 5% reduction in bonding strength. PMID:12937863

Fenske, Christian; Sadat-Khonsari, Reza; Bauss, Oskar; Seedorf, Hartwig; Kirsch, Ingo; Kahl-Nieke, Bärbel; Jüde, Hans Dieter

2003-07-01

22

Influence of adherend’s delamination on the response of single lap and socket tubular adhesively bonded joints subjected to torsion  

Microsoft Academic Search

Tubular adhesively bonded joints are widely used in many industries such as the oil-and-gas, aerospace and automotive. Such joints are often used to mate dissimilar materials. Composite materials, because of their superior specific strength and stiffness and high resistance to corrosion, have also been widely used to form tubular components. When composites are mated to other materials (such as metals)

Ramadan A. Esmaeel; Farid Taheri

2011-01-01

23

Properties of adhesive joint of inorganic nano-filler composite adhesive  

Microsoft Academic Search

The characteristics of adhesive joints of aluminium sheet containing epoxy based composite adhesives containing nano- filler of ZrO2 powder have been studied. The composite adhesives containing 10, 15 and 20wt.% of about 20±3 nm size ZrO2 powder are applied to mechanically treated aluminium substrates. The single lap joints of the composite adhesive are characterized by their tensile lap shear strength

P K Ghosh; S K Nukala

24

An examination of faying surface fretting in single lap splices  

NASA Astrophysics Data System (ADS)

While fretting damage in mechanically fastened joints is widely acknowledged as a common source of crack nucleation, little work is available in the open literature on the role that fretting damage plays in the fatigue life of a riveted joint. To expand on the limited knowledge available, a study was undertaken on fretting fatigue in thin-sheet riveted fuselage lap joints. In joints constructed out of 1 mm thick 2024-T3 aluminum sheet the rivet forming load was found to have a significant effect on the location of fretting damage and crack nucleation. This effect was observed for splices riveted with machine countersunk and with universal rivets. The shift in the location of peak fretting damage and crack nucleation with changing rivet forming loads was investigated through numerical and experimental methods. A predictive model based on the critical plane Smith-Watson-Topper strain life equation was applied to the complex geometry of the single lap splice and was shown to be effective in predicting the fretting fatigue life as well as the location of fretting-induced crack nucleation. Basing this model on an explicit finite element simulation allowed for the inclusion of compressive residual stresses generated during rivet forming. Key to the proper functionality of the predictive model was to have a validated finite element model from which results for the stress and strain field in the loaded component could be obtained. In addition to the predictive model, a series of splice coupon and simplified geometry fretting fatigue tests were performed. The tests showed that, at higher rivet forming loads, crack nucleation is on the faying surface away from the hole edge and that the type of surface condition is important to the fretting fatigue life of the splice. The discovery of this variation with surface treatment at high rivet forming loads is important as more research is showing the benefit of using load-controlled rivet forming and higher rivet forming loads in the manufacturing of lap splices to increase the fatigue life.

Brown, Adam

25

Damage and failure analysis of co-cured fiber-reinforced composite joints  

NASA Astrophysics Data System (ADS)

Joints represent a design challenge, especially for composite structures. Among the available joining methods, co-curing is an efficient way to integrate parts for some applications. Coates and Armanios have proposed a Single Nested Overlap (SNO) co-cured joint configuration, obtained from a single lap joint through the overlap/interleafing of the adjoining top/bottom adherend plies, respectively. Through a comparative investigation, they have demonstrated joint strength and fatigue life improvements over the single lap joint counterparts for unidirectional and quasi-isotropic adherend lay-ups. This research extends the comparative investigation of Coates and Armanios by focusing upon characterizing and differentiating the damage initiation and progression mechanisms under quasi-static loading. Six specimen configurations are manufactured and tested. It is confirmed that single nested overlap joints show 29.2% and 27.4% average improvement in strength over single lap counterparts for zero-degree unidirectional and quasi-isotropic lay-ups, respectively. Several nondestructive evaluation techniques are used to observe and analyze damage initiation, damage progression and failure modes of the studied specimens and to monitor their mechanical response. Using X-ray Radiography and Optical Microscopy techniques during quasi-static loading, a physical characterization of damage and failure mechanisms is obtained. The acoustic emission data acquired during monotonic loading could reveal the overall picture of AE activities produced by the damage initiation, development and accumulation mechanisms within the specimen via parametric analysis. Further AE analysis by a selected supervised clustering method is carried out and shown successful in differentiating and clustering the AE data. Correlation with physical observations from other techniques suggests that the resulting clusters may be associated to specific damage modes and failure mechanisms.

Cao, Caihua

26

Environmental Durability of Materials and Bonded Joints Involving Fiber Reinforced Polymers and Concerte  

NASA Astrophysics Data System (ADS)

This paper describes the research work undertaken to evaluate the performance of materials and bonded joints involving Fibre Reinforced Polymers (FRPs) and concrete. Experimental variables ncluded polymer composite materials, test methods and environmental test conditions. Tensile and flexural tests were carried out to determine short term and long term environmental durability of composite materials. Single lap shear, a modified wedge cleavage and pull-off adhesion tests were used to study the performance of bonded joints. It is shown the tensile strength of composite materials can be affected after exposure to hot/humid conditions. The performance of stressed single lap joints was also affected by hot/humid conditions.

Gavari, Mahdi Mansouri; Rad, A. Yazdi; Gavari, Mohsen Mansouri

2008-08-01

27

Formation of tough composite joints  

SciTech Connect

Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si{sub 3}N{sub 4}-coated fibers had a 0/90{degree} architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses.

Brun, M.K. [GE Corporate Research and Development, Schenectady, NY (United States)

1997-05-01

28

An examination of faying surface fretting in single lap splices  

Microsoft Academic Search

While fretting damage in mechanically fastened joints is widely acknowledged as a common source of crack nucleation, little work is available in the open literature on the role that fretting damage plays in the fatigue life of a riveted joint. To expand on the limited knowledge available, a study was undertaken on fretting fatigue in thin-sheet riveted fuselage lap joints.

Adam Brown

2008-01-01

29

Finite element modeling and optimization of load transfer in multi-fastener joints using structural elements  

Microsoft Academic Search

A computationally effective model of a multi-fastener, single-lap, composite-to-aluminium joint has been developed by means of structural finite elements. The model is geared towards accurate predictions of load distribution between the fasteners and accounts for bolt-hole clearances, bolt clamp-up and member plate friction. Comparisons with previously conducted experiments and detailed finite element analyses validated the accuracy of the model. A

Johan Ekh; Joakim Schön

2008-01-01

30

THERMAL BEHAVIOR DURING THERMOPLASTIC COMPOSITES RESISTANCE WELDING  

Microsoft Academic Search

Two- and three- dimensional heat transfer finite element models of the resistance-welding process for joining thermoplastic composite laminates were developed. The models simulated a resistance welded single lap-shear joint using 16-layer unidirectional APC- 2\\/AS4 laminates. The heating element consisted of a stainless steel metal mesh sandwiched between neat PEEK films. The heat was generated at the bond surface by applying

Edith Talbot; Ali Yousefpour; Pascal Hubert; Mehdi Hojjati

31

Ceramic matrix composite-metal brazed joints  

Microsoft Academic Search

A silicon nitride fibre-reinforced cordierite glass ceramic matrix composite has been brazed to titanium and stainless steel in argon with four different interlayer materials, copper, nickel, tungsten and a metal matrix composite (mmc). Joints were tested in shear and all but one failed in the ceramic composite. The highest strength joint, using a metal matrix interlayer to join cmc to

D. G. Dixon

1995-01-01

32

Influence of bolt spacing and degree of anisotropy in single-lap joints  

Microsoft Academic Search

This study concerns the effect of bolt spacing and degree of anisotropy on the bolt load distribution and nature of the failure mechanism. Bolt loads and failure prediction are determined using a solution method that treats the contact stresses and contact region as unknowns. Utilizing the boundary collocation technique, this method provides the non-linear solution while capturing the effects of

B Sergeev; E Madenci; D. R Ambur

2000-01-01

33

Composite material stub-blade wing joint  

NASA Astrophysics Data System (ADS)

The viability of a composite stub-blade wing joint for high-altitude long-endurance aircraft was investigated in a joint-design study. The results of an analysis show that the resulting joint design is capable of carrying moderately high bending, shear, and torsional loads. The stub-blade wing joint design is weight-competitive with the traditional tension-type wing joint. In addition, it offers attractive features such as the ease of assembly and disassembly, the ease of fabrication, and an aerodynamic smoothness.

Franklin, Walter M.; Kreimendahl, Bryan W.

34

Behavior of bolted joints in composite laminates  

Microsoft Academic Search

This investigation characterizes bolted joint strength in Kevlar\\/epoxy and graphite\\/epoxy (0\\/45\\/90\\/-45)ââ composite laminates. The fundamental problem of a single bolt hole loaded symmetrically in tension is addressed. The first objective is to generalize the relationships between width, edge distance, hole size, thickness, washer diameter, and degree of lateral constraint with bolted joint strength based on experimental observations. The second objective

Jurf

1986-01-01

35

Analysis of Adhesively Bonded Riveted Joints  

Microsoft Academic Search

This paper represents the analysis and modeling of adhesively bonded single lap riveted joints. The present work aimed at recommending appropriate configuration and characterization of these joints for maximum utilization. The present study includes the effectiveness of bond line thickness, the bonded layer configuration, and the situation of dissimilar thickness joints. The finite-element technique was used throughout the analysis of

Ali M. Al-Samhan

36

Failure Load Prediction of Mechanically Fastened Composite Joints  

Microsoft Academic Search

With the wide application of fiber-reinforced composite material in aero-structures and mechanical parts, the design of composite joints has become a very important research area because they are often the weakest regions in composite structures. In this paper, a failure area index method is proposed to predict failure loads of mechanically fastened composite joints under plane stress condition with the

Jin-Ho Choi; Young-Jun Chun

2003-01-01

37

Effect of joint flexibility in adhesively bonded composite panel-to-flange joints  

Microsoft Academic Search

An experimental and numerical study was conducted to investigate the postbuckling induced failure in adhesively bonded composite postbuckled panel-to-flange (ABPTF) joints. Each ABPTF joint structure consists of two laminated flanges bonded to a long laminated panel. When the ABPTF joint structure is loaded in compression, the long panel buckles and then generates a relatively large peel stress in the joints.

L. Tong; A. Sheppard; D. Kelly; P. Chalkley

1998-01-01

38

Analysis of Composite Corrugated Panel Facesheet to Flange Joints  

Microsoft Academic Search

This paper outlines a method for the stress analysis of bonded composite corrugated panel facesheet to flange joints. The method relies on the existing HyperSizer Joints software, which analyzes the bonded joint, along with a beam analogy model that provides the necessary boundary loading conditions to the joint analysis. The method is capable of predicting the full multiaxial stress and

Phillip W. Yarrington; Craig S. Collier; Brett A. Bednarcyk

39

Testing composite-to-metal tubular lap joints  

NASA Astrophysics Data System (ADS)

Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

Guess, T. R.; Reedy, E. D., Jr.; Slavin, A. M.

40

Testing composite-to-metal tubular lap joints  

SciTech Connect

Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

Guess, T.R.; Reedy, E.D. Jr.; Slavin, A.M.

1993-11-01

41

Processing and modelling of resistance welding of APC-2 composite  

NASA Astrophysics Data System (ADS)

The process for resistance welding of APC-2 composite has been developed with the aid of thermal analysis using two-dimensional finite element modeling. The numerical prediction was used as a guide for selecting the processing parameters. Single-lap shear testing and microstructure viewing were employed for bonding evaluation. Resistance welded joints achieved a shear strength 33.9 +/- 2.3 MPa and retained this strength after hot-wet conditioning. The fiber orientation adjacent to the bondline layer was found to have an influence on the failure mode and thus the shear strength.

Xiao, X. R.; Hoa, S. V.; Street, K. N.

42

Contact analysis for riveted and bolted joints of composite laminates  

NASA Astrophysics Data System (ADS)

The computational strategy and numerical technique developed are demonstrated to be efficient for the analysis of riveted and bolted joints of composite laminates. The 3D contact analysis provides more accurate results for the evaluation of strength of the mechanically fastened joints in the composite structures. The method described can be extended to multibody contact problems, it has been implemented in the computer codes.

Ye, Tian-Qi; Li, Wei; Shen, Guanqing

43

Contact analysis for riveted and bolted joints of composite laminates  

Microsoft Academic Search

The computational strategy and numerical technique developed are demonstrated to be efficient for the analysis of riveted and bolted joints of composite laminates. The 3D contact analysis provides more accurate results for the evaluation of strength of the mechanically fastened joints in the composite structures. The method described can be extended to multibody contact problems, it has been implemented in

Tian-Qi Ye; Wei Li; Guanqing Shen

1992-01-01

44

Bearing failure analysis of mechanically fastened joints in composite laminates  

Microsoft Academic Search

An experimental investigation was performed to study the effects of stacking sequence and clamping force on delamination bearing strengths of mechanically fastened joints in carbon\\/epoxy composite laminates using acoustic emission (AE) technique. The experimental work of the study was presented in [H.J. Park, Effects of stacking sequence and clamping force on the bearing strengths of mechanically fastened joints in composite

Heung-Joon Park

2001-01-01

45

Bolted joints in a laminated composite strut design expert system  

Microsoft Academic Search

A knowledge-based expert system for the design and analysis of composite laminated struts with bolted joints is described. This system is part of a Composite Design Expert System aimed at performing analysis and design of composite laminated plates and struts and at assessing designs. The system uses a minimum weight optimization that satisfies the failure criteria of local and overall

C. M. L. Wu

1992-01-01

46

A rotary joint sensor using ionic polymer metallic composite  

Microsoft Academic Search

Ionic Polymer Metallic Composite (IPMC) is a smart material that can be used to make sensors for various applications. This paper investigates the use of IPMC for sensing the motion of a rotary joint. In this research, the relationship between the motion of a rotary joint and the IPMC sensor's voltage output was investigated and modeled. The relationships defining the

A. van den Hurk; X. J. Chew; K. C. Aw; S. Q. Xie

2009-01-01

47

Thermomigration in SnPb composite flip chip solder joints  

NASA Astrophysics Data System (ADS)

We have used composite flip chip solder joints to study thermomigration. The composite solder joint has 97Pb3Sn on the Si side and eutectic 37Pb63Sn on the substrate side. Redistribution of Sn and Pb occurs in thermomigration, and we found that Sn has moved to the Si side (the hot end) and Pb to the substrate side (the cold end). We estimate the driving force that a temperature gradient of 1000 °C/cm or a temperature difference of 10 °C across a solder joint of 100 ?m in diameter is sufficient to induce the thermomigration.

Huang, Annie T.; Gusak, A. M.; Tu, K. N.; Lai, Yi-Shao

2006-04-01

48

STUDY OF A COMPOSITE-TO-METAL TUBULAR JOINT  

Microsoft Academic Search

The paper reports the study carried out for the realization of a composite-to-metal tubular joint of a steel flange adhesively bonded to a carbon fiber epoxy composite shaft subjected to traction and torsion. In particular a finite element method has been employed to study the yielding of the adhesive and to characterize the stress concentration associated with the boundary effect

Silvio Pappadà; Rocco Rametta; Maria Antonietta Aiello; Alfonso Maffezzoli

49

HYBRID COMPOSITE LAMINATES FOR HIGH-PERFORMANCE BOLTED JOINTS  

Microsoft Academic Search

One of the main methods used for joining composite components for aircraft and spacecraft applications is mechanical fastening (1). Mechanically fastened joints have the advantages of reliability, detachability and inspectability, and represent a well-established and well-known method. However, to reach a satisfactory structural coupling efficiency with composite materials is much more challenging than it is for metals due to the

Pedro P. Camanho; Soraia Pimenta; Axel Fink; Andreas Orbst

50

Analysis of mechanically fastened composite joints by boundary element methods  

Microsoft Academic Search

This article focuses on the boundary element formulation development for analyzing a mechanically bolted composite. Boundary equations are formulated for all the member panels of the composite joints. These equations are solved together with the fastener equations to get the resultant contact forces for all the fasteners involved. The fasteners are then modeled as 1D springs that are governed by

S. T. Lie; G. Yu; Z. Zhao

2000-01-01

51

Fatigue in mechanically fastened composite and metallic joints  

SciTech Connect

This book presents the papers given at a conference on the fatigue of metals and composite materials. Topics considered at the conference included advanced fastener technology for composite and metallic joints, cold working, the experimental characterization of cracks, fastener flexibility, and the enhanced stop-drill repair procedure for cracked structures.

Potter, J.M.

1985-01-01

52

Defect assessment of bonded joints of composite tubes using shearography  

NASA Astrophysics Data System (ADS)

Composite materials tubes are being used in various industrial segments, including the oil and gas industry1. The union between adjacent composite tubes is often accomplished through adhesives, and thus the inspection for flaws in adhesive-bonded joints becomes crucial. In this context, tubes and elbows made of epoxy resin reinforced with glass fiber were assembled with adhesive in the Quick-Lock® 1 configuration forming loops (spools). During the assemblage of these loops, artificial defects (areas without adhesive or disbondings) were inserted in its joints to evaluate the capability of failure detection by shearography. This paper presents and discusses results obtained with shearography. Shearography demonstrated great potential for application in the adhesive-bonded joints inspection, as it detected all defects artificially inserted and also real defects present in the loops joints.

Willemann, Daniel P.; Fantin, Analucia; Albertazzi Gonçalves, Armando, Jr.

2010-09-01

53

21 CFR 888.3490 - Knee joint femorotibial metal/composite non-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...Knee joint femorotibial metal/composite non-constrained cemented prosthesis...knee joint femorotibial metal/composite non-constrained cemented...molecular weight polyethylene with carbon fibers composite and are intended for use...

2009-04-01

54

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...3100 Ankle joint metal/composite semi-constrained cemented...Identification. An ankle joint metal/composite semi-constrained cemented...molecular weight polyethylene with carbon fibers composite, and is limited to those...

2009-04-01

55

21 CFR 888.3490 - Knee joint femorotibial metal/composite non-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...Knee joint femorotibial metal/composite non-constrained cemented prosthesis...knee joint femorotibial metal/composite non-constrained cemented...molecular weight polyethylene with carbon fibers composite and are intended for use...

2010-04-01

56

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...3100 Ankle joint metal/composite semi-constrained cemented...Identification. An ankle joint metal/composite semi-constrained cemented...molecular weight polyethylene with carbon fibers composite, and is limited to those...

2010-04-01

57

21 CFR 888.3500 - Knee joint femorotibial metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...Knee joint femorotibial metal/composite semi-constrained cemented...knee joint femorotibial metal/composite semi-constrained cemented...molecular weight polyethylene with carbon-fibers composite and is limited to those...

2010-04-01

58

21 CFR 888.3500 - Knee joint femorotibial metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...Knee joint femorotibial metal/composite semi-constrained cemented...knee joint femorotibial metal/composite semi-constrained cemented...molecular weight polyethylene with carbon-fibers composite and is limited to those...

2009-04-01

59

21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...888.3340 Hip joint metal/composite semi-constrained cemented...Identification. A hip joint metal/composite semi-constrained cemented...molecular weight polyethylene with carbon fibers composite. Both components are...

2009-04-01

60

21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...888.3340 Hip joint metal/composite semi-constrained cemented...Identification. A hip joint metal/composite semi-constrained cemented...molecular weight polyethylene with carbon fibers composite. Both components are...

2010-04-01

61

Fatigue failure of composite bolted joints  

SciTech Connect

The effects of a number of parameters on the fatigue characteristics of a bolted graphite/epoxy composite laminate are investigated. In particular, tests were performed in order to study the influence of three independent parameters; applied stress level, orientation of the outer layer reinforcing filaments, and the bolt torque level on the fatigue life of a graphite/epoxy composite. Analysis of variance and censoring techniques were used to analyze the experimentally obtained data. Fatigue life data was determined to be adequately characterized by using a log-normal distribution. 29 refs.

Herrington, P.D.; Sabbaghian, M. (New Orleans Univ., LA (United States) Louisiana State Univ., Baton Rouge (United States))

1993-01-01

62

Strength of Mechanically Fastened Composite Joints  

Microsoft Academic Search

A method is presented for predicting the failure strength and failure mode of mechanically fastened fiber reinforced composite laminates. The method in cludes two steps. First, the stress distribution in the laminate is calculated by the use of a finite element method. Second, the failure load and the failure mode are predicted by means of a proposed failure hypothesis together

Fu-Kuo Chang; Richard A. Scott; George S. Springer

1982-01-01

63

The strength of metal-matrix composite joints  

SciTech Connect

The mechanical performance of model butt joints between Al-matrix composites reinforced with continuous alumina fibers has been investigated. The joints consisted of thin metal interlayers of varying geometries and thicknesses, normal to the fiber preforms with prescribed discontinuities in them, thus ensuring matrix continuity through the interlayer and minimization of processing defects normally introduced in actual joining operations. Tensile strengths for reference composite specimens with volume fractions in the 60{+-}5 vol.% range were on the order of 700 MPa, compared with a matrix yield strength of {sigma}{sub 0}{approx}100 MPa. Measured joint strengths were {approximately}250 MPa for interlayers of uniform thickness (60 and 300 {micro}m) wherein plane strain conditions predominated, and {approximately}170 MPa for interlayers of variable thickness ({le} 6.4 mm) wherein conditions changed from plane strain to plane stress. The predominant mode of failure was interfacial debonding at an estimated local stress of {approximately}260 MPa. An upper limit to the joint strength was identified as arising from unstable cavitation in the metal interlayer, expected at a stress of {approximately}4{sigma}{sub 0}. Possible avenues to increase the joint strength to a level consistent with that of the composite are discussed in light of the understanding of failure mechanisms emerging from these model configurations.

Burr, A.; Yang, J.Y.; Levi, C.G.; Leckie, F.A. [Univ. of California, Santa Barbara, CA (United States). Dept. of Materials and Mechanical Engineering

1995-09-01

64

Defect assessment of bonded joints of composite tubes using shearography  

Microsoft Academic Search

Composite materials tubes are being used in various industrial segments, including the oil and gas industry1. The union between adjacent composite tubes is often accomplished through adhesives, and thus the inspection for flaws in adhesive-bonded joints becomes crucial. In this context, tubes and elbows made of epoxy resin reinforced with glass fiber were assembled with adhesive in the Quick-Lock® 1

Daniel P. Willemann; Analucia Fantin; Armando Albertazzi Gonçalves Jr.

2010-01-01

65

Strength prediction of tubular composite adhesive joints under torsion  

Microsoft Academic Search

This paper addresses prediction of the strength of tubular adhesive joints with composite adherends by combining thermal and mechanical analyses. A finite element analysis was used to calculate the residual thermal stresses generated by cooling down from the adhesive cure temperature, and a nonlinear analysis incorporating the nonlinear adhesive behavior was performed to accurately estimate the mechanical stresses in the

Je Hoon Oh

2007-01-01

66

Mechanical Jointing in Aramid Fiber Composites: An Experimental Study.  

National Technical Information Service (NTIS)

Mechanical jointing of Aramid was compared with carbon fiber and aluminum laminates. The laminate composition for Aramid is not critical if 20% to 30% of the fibers are oriented at +or- 45 deg. For an optimized carbon fiber laminate 60% of the fibers have...

C. A. M. Dekoning W. H. M. Dreumel

1983-01-01

67

Fracture Behaviour of Adhesively Bonded Joints in Sandwich Composite Beams  

Microsoft Academic Search

Adhesive bonding is widely accepted as one of the most efficient and practical techniques for joining fiber-reinforced polymer (FRP) adherends. Additionally, configuration of such adherends with a core material into a sandwich composite produces structural elements with superior flexural stiffness and strength. While several studies have investigated the performance of bonded joints of FRP adherends, investigations into characterization of bonded

Khaled Shahin; Farid Taheri

2009-01-01

68

Stress analyses of a smart composite pipe joint integrated with piezoelectric composite layers under torsion loading  

Microsoft Academic Search

In order to improve the joint failure strength, an adhesively bonded smart composite pipe joint system has been developed by integrating electromechanical coupling piezoelectric layers with the connection coupler. It has been validated that the integrated piezoelectric ceramic layers can smartly reduce stress concentration in the adhesive layer bond-line under bending or axial tension loads. In this study, piezoelectric particle\\/fiber

Jinquan Cheng; Guoqiang Li

2008-01-01

69

Bolted joints in a laminated composite strut design expert system  

NASA Astrophysics Data System (ADS)

A knowledge-based expert system for the design and analysis of composite laminated struts with bolted joints is described. This system is part of a Composite Design Expert System aimed at performing analysis and design of composite laminated plates and struts and at assessing designs. The system uses a minimum weight optimization that satisfies the failure criteria of local and overall buckling, and a stress/strain failure criterion. Emphasis is placed on the formulation for the minimum weight optimization of struts with bolted joints. Attention is also given to a procedure for optimizing a strut to be fitted in a given length of a gap and the assessment of competing strut designs.

Wu, C. M. L.

70

Experimental study on semi-rigid composite joints with steel beams and precast hollowcore slabs  

Microsoft Academic Search

The concept of semi-rigid composite connection has been widely researched in the past; however, most of the researches are limited to composite joints with metal deck flooring and solid concrete slabs. Composite construction incorporating precast concrete hollowcore slabs (HCU) is a recently developed composite floor system for buildings. The research on the structural behaviour of the semi-rigid composite joints with

F. Fu; D. Lam

2006-01-01

71

A rotary joint sensor using ionic polymer metallic composite  

NASA Astrophysics Data System (ADS)

Ionic Polymer Metallic Composite (IPMC) is a smart material that can be used to make sensors for various applications. This paper investigates the use of IPMC for sensing the motion of a rotary joint. In this research, the relationship between the motion of a rotary joint and the IPMC sensor's voltage output was investigated and modeled. The relationships defining the sensor's response were developed into a routine which was used to calculate the bending angle and bending speed of a joint, based on the voltage response of an IPMC sensor. Experimental verification of the model produced results for measuring bending angles with an accuracy of within 3% across most of the range of angles. The accuracy of the measured bending speed was found to be related to the joint motion; with errors ranging from 0.4% at a slow bending speeds ( <=150°s-1) up to an error of ~8% at fast bending speeds ( >= 200°s-1). Additional variables such as bending direction and starting position were also investigated to determine their effects on the sensor's response. It is concluded that the methods developed in this study provide a more complete description of the relationship between IPMC sensor voltage and joint motion than has previously been documented.

van den Hurk, A.; Chew, X. J.; Aw, K. C.; Xie, S. Q.

2009-07-01

72

ElastoPlastic Failure Analysis of Composite Bolted Joints  

Microsoft Academic Search

An elasto-plastic finite element analysis of pin loaded joints in laminated composites has been investigated and comparisons made with both existing 2-D linear elastic plane stress analytical solutions and experimental results for a graphite\\/epoxy laminate. The finite element analysis included nonlinear material behavior after initial failure by assuming an elastic-perfectly plastic bimodular material model. Laminated plate theory was used to

Yoshifumi Tsujimoto; Dale Wilson

1986-01-01

73

Bonded lap joints of composite laminates with tapered edges  

Microsoft Academic Search

This study presents a semi-analytical solution method to analyze the geometrically nonlinear response of bonded composite lap joints with tapered and\\/or non tapered adherend edges under uniaxial tension. The solution method provides the transverse shear and normal stresses in the adhesives and in-plane stress resultants and bending moments in the adherends. The method utilizes the principle of virtual work in

E. Oterkus; A. Barut; E. Madenci; S SMELTZERIII; D. R. Ambur

2006-01-01

74

Resistance welding of thermoplastic composites skin\\/stringer joints  

Microsoft Academic Search

An experimental investigation of resistance welding of APC-2\\/AS4 PEEK\\/carbon fibre composite using a stainless steel mesh heating element is presented. A special specimen geometry, the skin\\/stringer configuration, was used to represent a typical reinforced aerospace structural joint. The specimens consisted of a flange, representing a stringer or frame, welded onto a skin laminate. The effects of the welding parameters such

M. Dubé; P. Hubert; A. Yousefpour; J. Denault

2007-01-01

75

Adhesive joint strength of hybrid assemblies: Titanium sheet-composites and aluminium sheet-composites—Experimental and numerical verification  

Microsoft Academic Search

This article presents the results of the testing of adhesive joint strength of hybrid assemblies consisting of different materials and joints of the same materials. Both experimental testing and numerical FEM analysis of the joints were applied. This type of joint can be found in the aviation industry, for example, where the use of composites as construction materials, including polymer

Anna Rudawska

2010-01-01

76

Comportement mecanique des joints boulonnes en composites verre-polyester  

NASA Astrophysics Data System (ADS)

Glass fibre-reinforced polyester composite materials are being extensively used for general-purpose applications. For highly loaded structures, bolted joints are generally the preferred assembly method. However, bolted joints are usually the weakest link in a structure and they must therefore be designed with care. Specifically, the joint geometry, reinforcement type and lay-up should be chosen on a rational basis, otherwise the assembly may fail prematurely. The present study is concerned with the study of these material parameters. The mechanical response of bolted assemblies is studied for a range of six glass fibre-reinforced polyester laminates with reinforcements and lay-ups that are typical for general-purpose applications. In order to assess how changes in joint width or in joint end distance affect the behaviour of the joint, tests were carried out on three coupon geometries. In accordance with the standard test method ASTM D5961, a single-bolt double lap bolted joint configuration was used for the experimental characterisation. We investigated how the displacement measurement could best be made because currently there is a whole range of approaches in use and it is clear that the measured displacement quantity directly affects the stiffness values. A 3-D finite element model indicated that bolt deformation and fixture deformations affected the measured coupon displacement. The bearing stiffness was reduced by 26% on average when the width was reduced from six to two times the hole diameter. For the assemblies with a width of two times the hole diameter (w/D = 2) the bearing stiffness increased clearly with the tensile modulus of the tested materials. Both the experimental and numerical bearing stiffness values were much lower than those predicted by joint flexibility formulas. Hence, our results indicate that these joint flexibility formulas should be adapted if they are intended to be used for design of general-purpose glass fibre-reinforced polyester structures with bolt-hole clearance. The different material/geometry combinations led to very diverse failure modes and strengths, ranging from catastrophic low strength failures to progressive high strength failures. All the small coupons (w/D = 2; e/D = 3) failed catastrophically by tension. We observed that important characteristics of the bearing response such as damage stress, ultimate strength, failure mode and post-failure behaviour were related to reinforcement types and their stacking sequence. (Abstract shortened by UMI.)

Vangrimde, Bart

77

Non-destructive testing of structural composites and adhesively bonded composite joints: pulsed thermography  

Microsoft Academic Search

Structural adhesive bonding is an enabling technology for the implementation of composite assemblies in automotive applications. Therefore, the quality and reliability of the composite bond must be assured. An advanced thermal non-destructive test (NDT) method, pulsed thermography, was evaluated for its capability to assess joint quality in an adhesively bonded composite pickup truck box. Pulsed thermography, used under in-plant, pre-production

J. A. Schroeder; T. Ahmed; B. Chaudhry; S. Shepard

2002-01-01

78

Increasing the efficiency of composite single-shear lap joints using bonded inserts  

Microsoft Academic Search

A numerical and experimental investigation on the use of bonded metallic inserts to increase the strength and the efficiency of single-shear composite bolted joints is presented. Metallic inserts bonded to a composite laminate are proposed to reduce the stress concentration factors at the hole of the composite laminate. Based on the results of numerical models of single-shear composite bolted joints,

P. P. Camanho; C. M. L. Tavares; R. de Oliveira; A. T. Marques; A. J. M. Ferreira

2005-01-01

79

A comprehensive assessment of adhesively bonded joints between sandwich composite beams  

Microsoft Academic Search

Assessment of adhesively bonded joints between sandwich composite beams are presented in this thesis in three parts, each is concerned with a distinct aspect of the joint behaviour. In physical order, these include the deformations of the entire joint assembly, the state of stress in the joint overlap region, and the strain energy release at the crack-tip at the end

Khaled Omar Shahin

2008-01-01

80

Experimental characterization of hybrid composite-to-metal bolted joints under flexural loading  

Microsoft Academic Search

Presented is an investigation of the structural performance of hybrid composite-to-metal bolted joints loaded in flexure. The main goal was to develop a watertight, hybrid connection to resist bending loads. The effect of bolt type, doubler plate geometry and foam inserts was studied. Fourteen different joint configurations were tested including standard bolted joints and bolted joints with doubler plates. The

Jean-Paul Kabche; Vincent Caccese; Keith A. Berube; Randy Bragg

2007-01-01

81

An estimation method of bearing strength of bolted joints in fibre reinforced composite  

Microsoft Academic Search

Some researchers have estimated the strength of bolted joints in fibre reinforced composite, using simple and efficient engineering procedures. However, for these procedures the effect of clamping due to the strength of bolted joints is not considered. In this paper, a method is presented for predicating critical bearing strength of single-hole bolted joints in composite on the basis of observing

Yang Ling

1986-01-01

82

Evaluation of the fatigue strength of adhesive joints based on interfacial fracture mechanics  

Microsoft Academic Search

Fatigue tests of the single lap adhesive joints (SLAJ) of thin mild steel plates were carried out and the effect of the thickness of the adhesive and plate on the fatigue strength was investigated. The boundary element 2D elastostatic analysis was also carried out and the effect of the adhesive and plate thickness on the stress distribution at the interface

Ryoji Yuuki; Jin-Qiao Liu; Jin-Ouan Xu; Toshiaki Ohira; Tomoyoshi Ono

1992-01-01

83

Effects of the environment and curing on the strength of adhesive joints  

Microsoft Academic Search

—The influences of four parameters - pretreatment of the adherend, curing cycle, time before testing, and humidity — on the strength of adhesively-bonded single lap joints were investigated for aluminium 2024-T3 adherend and modified epoxy FM73M adhesive. The importance of conditioning the aluminium surface prior to bonding was confirmed. Furthermore, the pretreatment should be attuned to the environmental conditions under

W. P. De Wilde; G. Van Vinckenroy; L. Tirry; A. H. Cardon

1995-01-01

84

Effects of Disbonds, Lightning Strikes, and Low-Velocity Impact Damage on Adhesively Bonded Composite Joints.  

National Technical Information Service (NTIS)

The purpose of this research was to investigate the static strength of adhesively bonded composite joints with the presence of large damage. The research addressed the concerns related to manufacturing and operational defects of bonded joints, i.e., diffe...

G. R. Pillai J. Tomblin W. Seneviratne

2009-01-01

85

Joint Composite-Rotation Adiabatic-Sweep Isotope Filtration  

PubMed Central

Joint composite-rotation adiabatic-sweep isotope filter are derived by combining the composite-rotation [A. C. Stuart, K. A. Borzilleri, J. M. Withka, and A. G. Palmer, J. Am. Chem. Soc. 121, 5346–5347 (1999)] and adiabatic-sweep [C. Zwahlen, P. Legault, S. J. F. Vincent, J. Greenblatt, R. Konrat, and L. E. Kay, J. Am. Chem. Soc. 119, 6711–6721 (1997); ?. Kup?e and R. Freeman, J. Magn. Reson. 127, 36–48 (1997)] approaches. The joint isotope filters have improved broadband filtration performance, even for extreme values of the one-bond 1H-13C scalar coupling constants in proteins and RNA molecules. An average Hamiltonian analysis is used to describe evolution of the heteronuclear scalar coupling interaction during the adiabatic sweeps within the isotope filter sequences. The new isotope filter elements permit improved selective detection of NMR resonance signals originating from 1H spins attached to an unlabeled natural abundance component of a complex in which other components are labeled with 13C and 15N isotopes.

Valentine, Elizabeth R.; Ferrage, Fabien; Massi, Francesca; Cowburn, David; Palmer, Arthur G.

2007-01-01

86

Viscoelastic adherend effects in adhesively bonded composite-to-composite joints  

SciTech Connect

This research is centered around characterizing a composite polymeric adherend material and studying, experimentally and theoretically, its reaction in one adhesive-joint configuration. The particular material investigated is a fibrous graphite/epoxy composite material with a rubber-toughened matrix. The composite is nonlinear and viscoelastic at room temperature. The objective of the study is to develop a constitutive equation to account for this behavior and to use it in a finite-element analysis of an adhesive joint. Experimental verifications of the constitutive model and adhesive joint are made. The graphite/epoxy composite is characterized using a viscoelastic model and a work-potential model. Unlike the viscoelastic model, the work-potential model accounts for changes in the microstructure, or damage, as well as viscoelasticity. The quasi-elastic method, in which the actual deformation behavior is approximately by a time-dependent elastic behavior, is used in the second characterization to account for the time dependence of the material. Parameters necessary for each model are determined from creep/recovery and constant-load-rate data.

Mignery, L.A.

1988-01-01

87

Adhesively-bonded joints in metallic alloys, polymers and composite materials: Mechanical and environmental durability performance  

Microsoft Academic Search

The factors affecting the mechanical and environmental durability (or stability), and performance of the adhesively bonded joints in various adherends including metallic alloys, polymers and composite materials are studied in detail. The primary function of a joint is to transfer load from one structural member to another. In most bonded joints the load transfer takes place through interfacial shear. At

A. Baldan

2004-01-01

88

21 CFR 26.47 - Role and composition of the Joint Sectoral Committee.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Role and composition of the Joint Sectoral Committee. 26...Medical Devices § 26.47 Role and composition of the Joint Sectoral Committee...equivalence of conformity assessment bodies (CAB's); (2) Developing...

2013-04-01

89

Analytical Model for Shear Strengthening of RC Beam-Column Joints Using Composite Materials  

Microsoft Academic Search

An analytical model, based on principal tensile stresses vs. joint shear deformation rules, for the evaluation of reinforced concrete (RC) joints strengthened with fibre reinforced polymer (FRP) composite materials is presented. For this purpose, existing model available in literature is simplified and step-by-step iterative procedure is given which separately evaluates the shear contributions provided by the composite material and by

S. Pampanin

90

Damage mode characterization of mechanically fastened composite joints using carbon nanotube networks  

Microsoft Academic Search

The practice of upgrading metal parts with composites in large structures has led to an increased use of composite joints, particularly mechanical fastenings, due to ease of assembly and replacement. A drawback of mechanical joints is that damage is difficult to detect visually. In this research, an embedded carbon nanotube network has been used to modify the conductivity of bolted

Sarah M. Friedrich; Amanda S. Wu; Erik T. Thostenson; Tsu-Wei Chou

2011-01-01

91

Failure of carbon composite-to-aluminum joints with combined mechanical fastening and adhesive bonding  

Microsoft Academic Search

Composite-to-aluminum double lap joints were tested to obtain the failure loads and modes for three types of joints: adhesive bonding, bolt fastening and adhesive-bolt hybrid joining. A film type adhesive FM73 and a paste type adhesive EA9394S were used for aluminum and composite bonding. A digital microscope camcorder was used to monitor the failure of the joints. It was found

Jin-Hwe Kweon; Jae-Woo Jung; Tae-Hwan Kim; Jin-Ho Choi; Dong-Hyun Kim

2006-01-01

92

Simulation of Impulse Resistance Welding for Thermoplastic Matrix Composites  

Microsoft Academic Search

The impulse resistance welding (IRW) process is modelled using a three-dimensional transient finite element model (FEM) featuring heat transfer and consolidation. The welding of single lap joints is simulated for APC-2 laminates, with additional PEEK film inserted at the welding interface. The effects of the power signal on (a) temperature uniformity in the welding interface and (b) processing times are

Christophe Ageorges; Lin Ye

2001-01-01

93

Experimental Investigation of Composite Pressure Vessel Performance and Joint Stiffness for Pyramid and Inverted Pyramid Joints.  

National Technical Information Service (NTIS)

The focus of this study is on the suitability in the application of classical laminate theory analysis tools for filament wound pressure vessels with adhesive laminated joints in particular: pressure vessel wall performance, joint stiffness and failure pr...

J. M. Verhage M. V. Bower

2001-01-01

94

Bolted Joints in Composite Structures: Design, Analysis and Verification. Task II. Test Results--Multifastener Joints.  

National Technical Information Service (NTIS)

Bolted joints are a prime means of load transfer in aircraft components. Compared to other joining techniques, they are reliable and structurally efficient, as well as cost effective. However, bolted joint locations give rise to stress concentrations and ...

E. Tossavainen R. L. Ramkumar

1985-01-01

95

Joints  

NSDL National Science Digital Library

Hinge joints move only in one direction, ball-and-socket joints are free to rotate in all directions, and gliding joints are able to move forward, backward, and side to side, but do not rotate freely.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-06

96

Effect of carbon nanotube reinforcement on fracture strength of composite adhesive joints  

Microsoft Academic Search

This study investigated the use of carbon nanotubes (CNTs) as an epoxy adhesive additive for adhesive joints between steel–composite\\u000a interfaces and composite–composite interfaces. The study also examined the effect of CNT functionalization to improve CNT\\u000a dispersion and thus improve joint strength. Specimens were constructed by adhesively bonding two parallel coupons, with a\\u000a starting crack at one end. The specimens were

Garrett L. Burkholder; Young W. Kwon; Randall D. Pollak

2011-01-01

97

Strengths of composite-to-metal double-lap bolted joints  

Microsoft Academic Search

A three-dimensional analysis was proposed to study the through-the-thickness clamping effect on the bearing failure of double-lap bolted laminated composite joints. Experiments were first performed to characterize the material response due to bearing failure in composite bolted joints with and without lateral clamp-up supports. Composite plates made of T800H\\/3900-2 graphite\\/epoxy were selected in the tests, and various washer sizes and

Hsien-Tang Sun

1998-01-01

98

Damage analysis in composite materials and design of adhesive joints for composite structures  

NASA Astrophysics Data System (ADS)

Interfacial debonding and damage evolution in composites. The local imperfect interface models were developed for the single spherical and cylindrical inclusion composites. In contrast with the classical results under perfect interface conditions, the strain and stress fields were no longer uniform in the inclusions. To facilitate using the results in micromechanics models, the average stress concentration factors and average Eshelby tensor were derived under imperfect interface conditions. Moreover, the energy release was also discussed for a single inclusion during interface deterioration. Evolution of distributed damage in heterogeneous solids was modeled using the Transformation Field Analysis method and the selected models of interface debonding in fibrous or particulate composites. In this approach, stress changes caused by local debonding under increasing overall loads were represented by residual stresses generated by damage-equivalent eigenstrains that acted together with the applied mechanical loading program and physically based local transformation strains on an undamaged elastic aggregate. Interaction of the actual and equivalent eigenstrains with the mechanical loads at any state of damage was described by certain transformation influence functions which provide explicit expressions for the local stresses at any current damage state. Damage rates were then derived from a prescribed probability distribution of interface strength and local energy released by debonding. Numerical simulations of damage evolution in a glass/elastomer composite indicate which of these two conditions controlled the process at different reinforcement densities and overall stress states. In general, the energy released by a single particle at given overall stress decreased with increasing reinforcement density, and in proportion to particle size. Therefore, dense reinforcement by smaller-diameter particles should enhance damage resistance of composite systems. Analysis and design of adhesive joints for composite structures . A new approach was explored for joining of thick, woven E-glass/vinyl ester composite laminated plates to steel or composite plates, with applications in naval ship structures. Adhesive was applied along through-the-thickness contoured interfaces, employing tongue-and-groove geometry. Both experimental and finite element modeling results were presented. They showed that adhesively bonded tongue-and-groove joints between steel and composite plates loaded in monotonically increasing longitudinal tension are stronger than conventional strap joints even in relatively thin plates. In particular, a single 0.25 in. wide and 8 or 12 in. long steel tongue, bonded by the Dexter-Hysol 9339 adhesive to a groove in a 0.5 in. thick laminated plate, can support a 20,000 lbs tension force. This force was expected to increase in proportion to plate thickness. Simple design rules indicate that the adhesive bond can be made stronger than that of the tongues, so that failure was transferred from the adhesive to the adherends. High joint efficiency can be achieved for any thickness of the joined plates.

Zhang, Jian

99

Load and resistance factor design (LRFD) approach for bolted joints in pultruded composites  

Microsoft Academic Search

The application of glass fiber-reinforced polymeric matrix composites in civil engineering structures has been increasing rapidly in recent years. Pultruded composites are attractive for structural applications because of their continuous production and excellent mechanical properties. The present study is intended to be a step in understanding bolted joints in pultruded composites. Specifically, bolted connections in pultruded plates are investigated for

R. Prabhakaran; Z. Razzaq; S. Devara

1996-01-01

100

Smart cure cycles for the adhesive joint of composite structures at cryogenic temperatures  

Microsoft Academic Search

Adhesive joints are employed for composite structures used at the cryogenic temperatures such as LNG (liquefied natural gas) insulating tanks and satellite structures. The strength of the adhesive joints at the cryogenic temperatures is influenced by the property variation of adhesive and the thermal residual stress generated due to the large temperature difference (?T) from the adhesive bonding process to

Kwan Ho Lee; Dai Gil Lee

2008-01-01

101

Thermal and geometrically non-linear stress analyses of an adhesively bonded composite tee joint  

Microsoft Academic Search

Adhesive bonding technique is used successfully for joining the carbon fibre reinforced plastics to metals or composite structures. A good design of adhesive joint with either simple or more complex geometry requires its stress and deformation states to be known for different boundary conditions. In case the adhesive joint is subjected to thermal loads, the thermal and mechanical mismatches of

M. Kemal Apalak; Recep Gunes; M. Onder Turaman; A. Alper Cerit

2003-01-01

102

Post-Failure Analysis of Bolted Composite Joints in Tension or Shear-Out Mode Failure  

Microsoft Academic Search

A progressive damage model was developed for bolted joints in laminated composites which may fail in either tension mode or shear-out mode. The model is capable of assess ing damage accumulated in laminates with arbitrary ply orientations during mechanical loading and of predicting the ultimate strength of the joints which failed in tension or shear-out mode. The model consists of

Fu-Kuo Chang; Kuo-Yen Chang

1987-01-01

103

Application of genetic algorithm for optimum design of bolted composite lap joints  

Microsoft Academic Search

The genetic algorithm (GA), a powerful optimization technique for multiple extrema functions in multidimensional search spaces, is applied in conjunction with stress analysis to achieve optimum designs of bolted composite lap joints. The objective of the optimization is to ensure the highest strength of the joint. In this study, the laminate thickness, laminate lay-up, bolt location, bolt flexibility, and bolt

V. Kradinov; E. Madenci; D. R. Ambur

2007-01-01

104

An analytical solution for the analysis of symmetric composite adhesively bonded joints  

Microsoft Academic Search

Analytical solutions for adhesively bonded balanced composite and metallic joints are presented in this paper. The classical laminate plate theory and adhesive interface constitutive model are employed for this deduction. Both theoretical and numerical (finite element analysis) studies of the balanced joints are conducted to reveal the adhesive peel and shear stresses. The methodology can be extended to the application

G. P. Zou; K. Shahin; F. Taheri

2004-01-01

105

Failure analysis of woven kevlar fiber reinforced epoxy composites pinned joints  

Microsoft Academic Search

An investigation was performed to determine the failure mode and the failure load of mechanically fastened joints in woven kevlar epoxy composite plates. Two-dimensional finite element code is developed to predict damage initiation, progression and strength of joints. Hashin, Hoffman and Maximum Stress criteria were used in this failure analysis. Experiments were performed to find the failure load and to

Bülent Murat ?çten; Ramazan Karakuzu; M. Evren Toygar

2006-01-01

106

Mechanics of mechanically fastened joints in polymer–matrix composite structures – A review  

Microsoft Academic Search

As the applications of advanced composite structural materials continue to increase, so does the need to understand the mechanical behavior of mechanically fastened joints in such structures. The most recent and relevant review article on this subject was published more than a decade ago, but it was restricted to stress analysis and strength prediction of mechanically fastened joints in fiber-reinforced

Srinivasa D. Thoppul; Joana Finegan; Ronald F. Gibson

2009-01-01

107

An analytical method for failure prediction of multi-fastener composite joints  

Microsoft Academic Search

An analytical method is developed for failure prediction of composite bolted joints with multiple fasteners. The flexibility of all members in the joint is taken into account. A complex variational approach is proposed for the stress analysis of the component plates which involves multiple loaded holes and a strength of materials approach is used for the analysis of fasteners which

Y. Xiong

1996-01-01

108

A design methodology for mechanically fastened joints in laminated composite materials  

Microsoft Academic Search

This paper presents a new methodology to predict the onset of damage, final failure and failure mode of mechanically fastened joints in composite laminates. The stress distribution at each ply is obtained using semi-analytical or numerical methods. The elastic limit of the joint is predicted using the ply strengths and stress distribution in failure criteria. Final failure and failure mode

P. P. Camanho; M. Lambert

2006-01-01

109

21 CFR 26.47 - Role and composition of the Joint Sectoral Committee.  

Code of Federal Regulations, 2010 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...MUTUAL RECOGNITION OF PHARMACEUTICAL...MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED...26.47 Role and composition of the Joint Sectoral...conformity assessment bodies (CAB's);...

2010-04-01

110

21 CFR 26.47 - Role and composition of the Joint Sectoral Committee.  

Code of Federal Regulations, 2010 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...MUTUAL RECOGNITION OF PHARMACEUTICAL...MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED...26.47 Role and composition of the Joint Sectoral...conformity assessment bodies (CAB's);...

2009-04-01

111

Synthesis Procedure for Mechanically Fastened Joints in Advanced Composite Materials. Volume II.  

National Technical Information Service (NTIS)

The purpose of the study was to provide the composites designer with an automated preliminary design capability for weight minimized mechanically fastened joints and to identify the common characteristics of such minimum weight designs. The problem of a s...

J. P. Waszczak T. A. Cruse

1973-01-01

112

21 CFR 888.3500 - Knee joint femorotibial metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2013 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3500 Knee joint femorotibial metal/composite semi-constrained cemented prosthesis. (a)...

2013-04-01

113

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2013 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3100 Ankle joint metal/composite semi-constrained cemented prosthesis. (a)...

2013-04-01

114

Bolted Joints in a Laminated Composite Strut Design Expert System.  

National Technical Information Service (NTIS)

A knowledge based expert system (for the design and analysis of composite laminated struts) is part of a composite design expert (CODEX) system that not only performs analysis and design of composite laminated plates and struts, but also assesses competin...

C. M. L. Wu

1990-01-01

115

THE ROLE OF SCARF ANGLE IN THE PERFORMANCE OF ALUMINUM MATRIX COMPOSITE JOINTS  

Microsoft Academic Search

The role of geometry on the mechanical performance of scarf joints in Al-matrix composites reinforced with continuous polycrystalline alumina fibers was investigated. Model joints consisting of thin metal interlayers at varying scarf angles between composite sub-elements were designed, manufactured and tested to study the relevant deformation and failure phenomena. Specimens were produced by pressurized infiltration of molten Al-4.5%Mg into fiber

D. D. BRINK; C. G. LEVI; A. C. F. COCKS; F. A. LECKIE

1997-01-01

116

Microstructure and mechanical properties of joints in sintered SiC fiber-bonded ceramics brazed with Ag Cu Ti alloy  

SciTech Connect

Active metal brazing of a new high thermal conductivity sintered SiC-polycrystalline fiber-bonded ceramic (SA-Tyrannohexs) has been carried out using a Ti-containing Ag Cu active braze alloy (Cusil-ABAs). The brazed composite joints were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM EDS). The results show that this material can be successfully joined using judiciously selected off-the shelf active braze alloys to yield metallurgically sound joints possessing high integrity. Uniform and continuous joints were obtained irrespective of differences in the fiber orientation in the substrate material. Detailed interfacial microanalysis showed that the titanium reacts with C and Si to form TiC layer and a Ti Si compound, respectively. Furthermore, the evaluation of shear strength of the joints was also conducted at ambient and elevated temperatures in air using the single-lap offset (SLO) shear test. The perpendicular-type SA-Tyrannohex joints exhibited apparent shear strengths of about 42 MPa and 25 MPa at 650 1C and 750 1C, respectively. The fracture at the higher temperature occurred at the interface between the reactionformed TiC layer and braze. This might be caused by generation of stress intensity when a shear stress was applied, according to m-FEA simulation results.

Singh, Mrityunjay [NASA-Glenn Research Center, Cleveland; Asthana, Rajiv [University of Wisconsin-Stout, Menomonie; Ishikawa, Toshihiro [Ube Industries, Ltd.; Matsunaga, Tadashi [Ube Industries, Ltd.; Lin, Hua-Tay [ORNL

2012-01-01

117

Microstructure and Mechanical Properties of Joints in Sintered SiC Fiber-Bonded Ceramics Brazed with Ag-Cu-Ti Alloy  

SciTech Connect

Active metal brazing of a new high thermal conductivity sintered SiC-polycrystalline fiber-bonded ceramic (SA-Tyrannohex{reg_sign}) has been carried out using a Ti-containing Ag-Cu active braze alloy (Cusil-ABA{reg_sign}). The brazed composite joints were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDS). The results show that this material can be successfully joined using judiciously selected off-the shelf active braze alloys to yield metallurgically sound joints possessing high integrity. Uniform and continuous joints were obtained irrespective of differences in the fiber orientation in the substrate material. Detailed interfacial microanalysis showed that the titanium reacts with C and Si to form TiC layer and a Ti-Si compound, respectively. Furthermore, the evaluation of shear strength of the joints was also conducted at ambient and elevated temperatures in air using the single-lap offset (SLO) shear test. The perpendicular-type SA-Tyrannohex joints exhibited apparent shear strengths of about 42 MPa and 25 MPa at 650 C and 750 C, respectively. The fracture at the higher temperature occurred at the interface between the reaction-formed TiC layer and braze. This might be caused by generation of stress intensity when a shear stress was applied, according to {mu}-FEA simulation results.

Singh, Mrityunjay [NASA-Glenn Research Center, Cleveland; Matsunaga, Tadashi [ORNL; Lin, Hua-Tay [ORNL; Asthana, Rajiv [University of Wisconsin-Stout, Menomonie; Ishikawa, Toshihiro [Ube Industries, Ltd.

2012-01-01

118

Retarding Electromigration in Lead-Free Solder Joints by Alloying and Composite Approaches  

NASA Astrophysics Data System (ADS)

The voids induced by electromigration (EM) can trigger serious failure across the entire cathode interface of solder joints. In this study, alloying and composite approaches showed great potential for inhibiting EM in lead-free solder joints. Microsized Ni, Co, and Sb particles were added to the solder matrix. Cu and Sn particles were added to the melting solder to form in situ Cu6Sn5, which formed a barrier layer in the underbump metallization of flip-chip solder joints. The polarity effect induced by EM was observed to be significantly inhibited in the alloyed and composite solder joints. This indicates that the Sn-Ni, Sn-Co, Sn-Sb, and Cu6Sn5 intermetallic compounds may act as barriers to obstruct the movement of the dominant diffusion species along phase boundaries, which in turn improves the resistance to EM. However, Sb particles could induce crack formation and propagation that might lead to joint fracture.

Zhao, Ran; Ma, Limin; Zuo, Yong; Liu, Sihan; Guo, Fu

2013-02-01

119

Electromigration performance of Pb-free solder joints in terms of solder composition and joining path  

NASA Astrophysics Data System (ADS)

The electromigration (EM) performance of Pb-free solder joints is investigated in terms of solder composition (Sn-0.5Cu vs. Sn-1.8Ag) and joining path to Cu vs. Ni(P) under bump metallization (UBM). In the double-sided joints of Ni(P)/solder/Cu, the micro-structure of solder joints and the interfacial intermetallic compound (IMC) layers are significantly affected by solder composition and joining path. The as-reflowed microstructure of Sn-0.5Cu joints consists of small columnar grains with thin IMC layers at both UBM interfaces, independent of the joining path, while Sn-1.8Ag joints have a few large grains of low-angle grain boundaries with thick IMC layers when joined first to Ni(P) UBM, but a few 60° twins with thin IMC layers when joined first to Cu UBM. The EM stressing under high current densities at 150°C reveals that Sn-1.8Ag joints have a superior lifetime compared to Sn-0.5Cu joints. In addition, the EM lifetime of Sn-1.8Ag joints reflowed first on Ni(P) UBM is the longest among four groups of the solder joints examined.

Seo, Sun-Kyoung; Kang, Sung K.; Cho, Moon Gi; Lee, Hyuck Mo

2010-07-01

120

Damage state evaluation of adhesive composite joints using chaotic ultrasonic waves  

NASA Astrophysics Data System (ADS)

Ultrasonic chaotic excitations combined with sensor prediction algorithms have shown the ability to identify incipient damage (loss of preload) in a bolted joint. In this study we examine the capability of this damage detection scheme to identify disbonds and poorly cured bonds in a composite-to-composite adhesive joint. The test structure consists of a carbon fiber reinforced polymer (CFRP) plate that has been bonded to a CFRP rectangular tube/spar with several sizes of disbond as well as a poorly cured section. Each excitation signal is imparted to the CFRP plate through a macro-fiber composite (MFC) patch on one side of the adhesive joint and sensed using an equivalent MFC patch on the opposite side of the joint. A novel statistical classification feature is developed from information theory concepts of cross-prediction and interdependence. Temperature dependence of this newly developed feature will also be examined.

Fasel, Timothy R.; Todd, Michael D.; Park, Gyuhae

2009-03-01

121

Experimental Study of Fiberglass Composites Containing Metal Wire Joints.  

National Technical Information Service (NTIS)

The U.S. Navy has been incorporating increasing amounts of composite materials during construction, especially in the areas of submarine sails and surface ship superstructures. The benefit of using composite material with metal wire layers imbedded is tha...

J. E. Klopfer

2009-01-01

122

Analysis of a Bonded Joint in a Composite Tube Subjected to Torsion  

Microsoft Academic Search

The stress state in the bonded joint region of a laminated composite tube subjected to torsional and hygrothermal loadings is analyzed. A finite ele ment solution technique is utilized. The composite can be modeled ply-by-ply, and the adhesive as a separate elastic layer. All six stress components are pre sent in a generally orthotropic material subjected to torsion, and the

Stanley R. Graves; Donald F. Adams

1981-01-01

123

Contact analysis of mechanically fastened joints in composite laminates by linear complementarity problem formulation  

Microsoft Academic Search

The contact phenomena and stress distributions in the vicinity of the hole on mechanically fastened joints are investigated in composite laminates exhibiting nonlinear elastic behavior. The effects of fastener stiffness, friction force between the fastener and the composite laminates, geometrical nonlinearities due to concentrated fastener load around the hole edge for the snug and clearance-fit in the [0 °]S, [±

H. Y. Ko; B. M. Kwak

1997-01-01

124

Surface Modification by Nanoimprint Lithography for Improvement of the Joint Strength of Composites  

NASA Astrophysics Data System (ADS)

To improve the strength of adhesively bonded composite joints, surface modification of composites by nanoimprint lithography (NIL) is investigated. Since microstructures can be fabricated during the curing of composites, this technique reduces the time required and costs involved in conventional surface preparation such as chemical etching or sand blasting. Since structural adhesives are susceptible to peeling, a pyramidal microstructure is chosen for the surface modification pattern. Such a pattern divides the stress at the interface into peel and shear components; thus, the apparent joint strength is greater than that of an untreated joint with a flat surface. We fabricated the pyramidal microstructure on carbon fiber reinforced plastic and determined the adhesive strength both analytically and experimentally. In the analysis, interfacial stresses were calculated using the finite element method and the interfacial fracture was defined using the peel and shear mixed-mode criterion based on the average stress criterion. In the experiment, tensile butt joint tests were performed for NIL and untreated joints and the apparent strengths were measured. The NIL joint was found to be 52% stronger than the untreated joint according to the finite element method calculation and 67% stronger according to the tensile tests.

Matsuzaki, Ryosuke; Suzuki, Takuya

125

Anatomical composition of the anterior shoulder joint capsule. A cadaver study on 12 glenohumeral joints.  

PubMed

Twelve right cadaver shoulder joints were investigated after alcohol-formalin-glycerol fixation. The tendons of the "rotator cuff" were separated from the joint capsule. The capsulo-ligamentous structures: Lig. coracohumerale, Lig. coracoglenoidale and Ligg. glenohumeralia were dissected. In addition to the Ligg. glenohumerale superius, medium et inferius, an "unknown glenohumeral ligament" coursed in the midline of the superficial layer of the anterior shoulder joint capsule. It arose from the axillary part of the Lig. glenohumerale inferius and the insertion tendon of the Caput longum m. tricipitis brachii, coursed upwards laterally and fused with the Lig. glenohumerale medium. Between the Ligg. glenohumerale medium et inferius it was connected with the shoulder joint capsule by loose connective tissue. Craniolaterally it melted into the superior portion of the M. subscapularis and inserted together with its tendon to the Tuberculum minus of the Humerus. The ascending fibres of the "unknown glenohumeral ligament" and the oblique, descending fibres of the Ligg. glenohumeralia medium et inferius crossed twice and formed X-shape connections between the ligaments. In external rotation and abduction or anteversion the course of fibres of the "unknown glenohumeral ligament" was spiral. According to the shape and anatomical position of the "unknown glenohumeral ligament" we propose to name it "Lig. glenohumerale spirale". PMID:11206983

Kolts, I; Busch, L C; Tomusk, H; Rajavee, E; Eller, A; Russlies, M; Kühnel, W

2001-01-01

126

Novel strain energy dissipation mechanism for composite joint structure  

Microsoft Academic Search

The conventional method for reducing structureborne vibrations is by the application of parasitic viscoelastic claddings. To be effective that cladding needs to extensive, it adds weight to the structure and is often costly to apply and maintain. An effective strain energy dissipation method is described that is applicable to fiber reinforced structures and is localized to stiffeners or joints. An

Susan E. Mercy; John R. House; Ian D. Grant

1999-01-01

127

Damage sensing of adhesively-bonded hybrid composite\\/steel joints using carbon nanotubes  

Microsoft Academic Search

Carbon nanotube networks have been used previously for in situ sensing of matrix damage in fiber-reinforced composites. In this research, the ability of carbon nanotube networks to sense and distinguish different types of damage in adhesively-bonded hybrid composite-to-metal joints is evaluated. Toward this end, conductive networks of carbon nanotubes are introduced to the composite substrate as well as the epoxy

Amanda S. Lim; Zachary R. Melrose; Erik T. Thostenson; Tsu-Wei Chou

2011-01-01

128

CFRP\\/titanium hybrid material for improving composite bolted joints  

Microsoft Academic Search

The structural joining remains an essential challenge for the development of composite aerospace structures: every structural interconnection means a disturbance of an optimized structure resulting in an increase in overall structural weight. The lightweight potential of advanced, high-performance fiber composite materials is affected more strongly by mechanical fastening techniques than by conventional metallic materials due to the low shear and

B. Kolesnikov; L. Herbeck; A. Fink

2008-01-01

129

Strength scaling of adhesive joints in polymer–matrix composites  

Microsoft Academic Search

The fracture of adhesive joints between two glass-fibre laminates was studied by testing double cantilever beam test specimens loaded by uneven bending moments. A large-scale fracture process zone, consisting of a crack tip and a fibre bridging zone, developed. The mixed mode fracture resistance increased with increasing crack length, eventually reaching a steady-state level (R-curve behaviour). The steady-state fracture resistance

Bent F. Sørensen; Stergios Goutianos; Torben K. Jacobsen

2009-01-01

130

Strength of high temperature brazed joints:influence of brazing parameters  

Microsoft Academic Search

Investigations on strength of brazed joints in AISI Types 321 and 316 Ti stainless steel made with two metallurgically different high temperature filler metals (BAu-4 and BNi-5) demonstrated the influence of important brazing parameters. Using the AWS single-lap standard test method, several parameters-brazing cycle, condition (roughness) of the brazing surface, fixed and free-adjusting clearance - were varied. With the brittle

E. Lugscheider; K. Kloehn; R. Lison

1979-01-01

131

Fracture and strength of mechanically fastened joint in multi-axial flat braided composite  

NASA Astrophysics Data System (ADS)

Braided fabrics are useful as one of the techniques in realizing the concept of near-net shape in the reinforcement configuration of composite materials. It has been confirmed in our previous paper that a braided flat bar with a braided hole in which the fibers continuously orient, has high joint performance with small joint geometry. The effect of middle-end fibers is discussed. It is proved that performance of mechanically fastened joints with a braiding structure containing middle-end fibers is superior to structures without middle-end fibers. Moreover, the effect of the continuous fibers at the sides of the flat braid is also discussed.

Hamada, H.; Maekawa, Z.; Fujita, A.; Uozumi, T.

132

Design of adhesive bonded composite-to-titanium cylindrical joints  

NASA Astrophysics Data System (ADS)

The ASTER composite-case solid-rocket motor (SRM) development program has addressed the problem posed by the requirement of adhesively bonding a metallic dome attach ring to the filament-wound composite case. An account is given of the numerical and experimental activities undertaken to optimize and verify the design solution, whose full opening at the aft end of the motor case facilitates mandrel extraction and propellant grain shape flexibility.

Depasquale, F.; Ciranna, M.; Ciavatta, G.; Vittori, A.

1993-02-01

133

Design of adhesive bonded composite-to-titanium cylindrical joints  

Microsoft Academic Search

The ASTER composite-case solid-rocket motor (SRM) development program has addressed the problem posed by the requirement of adhesively bonding a metallic dome attach ring to the filament-wound composite case. An account is given of the numerical and experimental activities undertaken to optimize and verify the design solution, whose full opening at the aft end of the motor case facilitates mandrel

F. Depasquale; M. Ciranna; G. Ciavatta; A. Vittori

1993-01-01

134

Laser ablation assisted adhesive bonding of automotive structural composites  

SciTech Connect

Laser ablation has been evaluated as a surface pretreatment prior to adhesive bonding. In prior experimental work, it was observed that when adhesively bonded, composite, single lap shear samples fail, the fracture often occurs at either the adhesive/adherend interface or in the resin rich surface layer of the composite. These two areas represent the weakest portion of the joint. Laser ablation pretreatment generates areas where the resin on the composite surface is selectively removed leaving behind exposed reinforcing fibers which are the major load bearing members of the composite. In a subsequent adhesive bonding operation, this allows portions of the fibers to be encapsulated in the adhesive while other portions of the fiber remain in the composite resin. This type of pretreatment permits fibers to bridge and reinforce the interface between adhesive and adherend. A secondary benefit is the removal of surface contaminantes by pyrolysis. Microscopic observation of laser ablated surfaces indicates a prominent, fiber rich area. Results of the mechanical evaluation indicated that the lap shear strength for laser ablated samples was significantly higher than specimens with no pretreatment or with solvent cleaning only, but were slightly lower than specimens that were mechanically roughened and cleaned with solvents prior to bonding.

Boeman, R.G.; Paulauskas, F.L.; Warren, C.D.

1999-07-03

135

Strengths of composite-to-metal double-lap bolted joints  

NASA Astrophysics Data System (ADS)

A three-dimensional analysis was proposed to study the through-the-thickness clamping effect on the bearing failure of double-lap bolted laminated composite joints. Experiments were first performed to characterize the material response due to bearing failure in composite bolted joints with and without lateral clamp-up supports. Composite plates made of T800H/3900-2 graphite/epoxy were selected in the tests, and various washer sizes and clamping forces were used in the study. The clamping force in the bolt was found to vary with the applied load, and may increase significantly due to a sudden through-the-thickness expansion of the laminate under the washers where bearing failure occurred. Experiments showed that the joint strength and response can be significantly affected by the bolt clamp-up, and the bolt bearing failure is a 3-D phenomenon. In order to facilitate the use of the proposed model with the ABAQUS code, an interface module 3DBOLT was developed. In order to reinforce the incompressibility condition in calculations for bearing-damaged material predicted by the model, the condition was imposed through a penalty method in the frame work of finite element analyses. The module provides a user-friendly input deck, generates automatically a joint mesh, and produces outputs and graphics for displaying the stresses, strains, and deformations of the joints and for simulating the failure progression in joints during loading. Extensive comparisons were made between the test data and model predictions. Overall, the model predicts both the failure load and response of bolted composite joints very well for various clamping forces and washer sizes. The model also predicted very well for joints failed in net-tension and shear-out modes. The predicted bolt clamp-up load as a function of the applied load agreed also very well with the data, which validates that the proposed incompressibility assumption for bearing-damaged material. Based on the model, a parametric study was performed to evaluate the sensitivities of bearing load to bolt stiffness, clamping force, washer size, joint geometry such as joint width, edge-distance and bolt sizes. A design procedure was proposed based on the model to optimize the failure load of a joint with multiple holes in a row.

Sun, Hsien-Tang

136

Effects of stacking sequence and clamping force on the bearing strengths of mechanically fastened joints in composite laminates  

Microsoft Academic Search

The weakest parts of a composite laminate structure are often the joints. Hence the need to design reliable and efficient load-carrying joints has become increasingly important and the effects of stacking sequence and clamping force on joint strengths have to be clarified. In this study, the effects of stacking sequence and clamping force on delamination bearing strength and ultimate bearing

Heung-Joon Park

2001-01-01

137

An Investigation of the Tensile Strength of a Composite-To-Metal Adhesive Joint  

NASA Astrophysics Data System (ADS)

The present study examines the feasibility of a simple concept composite-to-metal butt joint through the performance of both numerical and experimental studies. The composite part is made of glass/epoxy unidirectional layers made with the vacuum bag method. The geometry of the joint is typical for marine applications and corresponds to a low stiffness ratio. Two major parameters are investigated, namely the overlap length and the surface preparation of the steel adherent. Manufacturing of specimens and the procedure of the tensile tests are described in detail, giving hints for obtaining a better quality joint. Axial elongation and strains at various places of the joint were monitored and also numerically calculated. The tests revealed that the joint is quite effective, irrespectively of the steel surface preparation method. The failure loads are comparable and in some cases superior to other corresponding values found in the literature. The numerical models proved to adequately predict the structural response of the joint up to the loading where debonding starts.

Tsouvalis, Nicholas G.; Karatzas, Vassilios A.

2011-04-01

138

SIMULATION OF PROGRESSIVE DAMAGE IN BOLTED COMPOSITE JOINTS  

Microsoft Academic Search

Recently, a continuum based progressive damage model for fiber-reinforced composites became available in the commercial finite element code ABAQUS. The implemented model uses the Hashin damage initiation criteria (1,2) and damage evolution is based on the work of Matzenmiller (3) and Camanho and Davila (4). The \\

Hannes Koerber; Pedro P. Camanho

139

Studies on the Performance of RC Beam-Column Joints Strengthened Using Different Composite Materials  

NASA Astrophysics Data System (ADS)

Many reinforced concrete structures in our country are in a deteriorated or distressed state. Hence strengthening such structures or reducing the load limit on them is becoming necessary to extend their service life. Beam-column joint is the crucial zone in a reinforced concrete moment resisting frame since it is subjected to large forces during severe ground shaking. In the present study, an attempt has been made to determine the cost-effective composite material and optimum number of layers of composite material for strengthening beam-column joints. Specimens were strengthened using ferrocement, glass fibre reinforced polymer (GFRP) and carbon fibre reinforced polymer (CFRP) and studied their behaviour under static as well as cyclic loading. It was found that the rotation at ultimate moment of all the strengthened beam-column joints were greater than that of the control specimens. The specimens strengthened with more number of layers of strengthening material showed better moment-rotation characteristics. The joints strengthened using GFRP showed better performance in terms of ultimate load, moment rotation characteristics, ductility, energy absorption capacity and strength-to-cost ratio, when compared to that of the specimens strengthened with other composite materials. However, CFRP strengthened specimens showed good ductility and better cracking characteristics and prevented the failure at the joint.

Sheela, S.; Anu Geetha, B.

2012-02-01

140

Influence of Bolting Parameters on the Ultimate Tensile Strength and Stiffness of Composite-Metal Joints  

Microsoft Academic Search

The joining of dissimilar materials poses a challenge in mechanical structures. The objective of this research was to investigate the effect of joining parameters such as bolt spacing, geometry configuration, and overlap length on ultimate failure strength and stiffness of composite-metal hybrid joints. Woven fiberglass\\/epoxy and unidirectional carbon-fiber\\/epoxy composites have been manufactured and tested under tensile loads to obtain their

William S. Slovinsky; Parsaoran Hutapea

2010-01-01

141

Lamb wave propagation in a restricted geometry composite pi-joint specimen  

NASA Astrophysics Data System (ADS)

The propagation of elastic waves in a material can involve a number of complex physical phenomena, resulting in both subtle and dramatic effects on detected signal content. In recent years, the use of advanced methods for characterizing and imaging elastic wave propagation and scattering processes has increased, where for example the use of scanning laser vibrometry and advanced computational models have been used very effectively to identify propagating modes, scattering phenomena, and damage feature interactions. In the present effort, the propagation of Lamb waves within a narrow, constrained geometry composite pi-joint structure are studied using 3D finite element models and scanning laser vibrometry measurements, where the effects of varying sample thickness, complex joint curvatures, and restricted structure geometries are highlighted, and a direct comparison of computational and experimental results are provided for simulated and realistic geometry composite pi-joint samples.

Blackshire, James L.; Soni, Som

2012-05-01

142

Fatigue testing welded joints for P/M Al-matrix composites  

NASA Astrophysics Data System (ADS)

To meet their need for high stiffness, many bicycles currently rely on aluminum-matrix composites. The highest strength and highest stiffness form of these material, 6092/B4C/15p, is produced by powder metallurgy techniques. The bicycles are tungsten inert-gas welded and fully heat treated after welding. A test technique has been developed to assess the static and fatigue properties of welded joints. This test technique has revealed the increased stiffness and strength of a 6092/B4C/15p-T6P composite tube joint as compared with a 6061-T6 aluminum one. This test technique is currently being used to identify fatigue properties for both tube joints.

Harrigan, William C.

1994-07-01

143

Analysis and Design of Tee-Joints for Composite Hull Structures.  

National Technical Information Service (NTIS)

The design of polymer matrix composite joints is strongly influenced by the presence of out-of-plane or through-the-thickness stresses. These stresses can be critical, since out-of-plane interlaminar tension and shear strengths, as well as moduli, are str...

J. Bish K. T. Kedward

1997-01-01

144

Diagnosis of Sacroiliac Joint Pain: Validity of individual provocation tests and composites of tests  

Microsoft Academic Search

Previous research indicates that physical examination cannot diagnose sacroiliac joint (SIJ) pathology. Earlier studies have not reported sensitivities and specificities of composites of provocation tests known to have acceptable inter-examiner reliability. This study examined the diagnostic power of pain provocation SIJ tests singly and in various combinations, in relation to an accepted criterion standard. In a blinded criterion-related validity design,

Mark Laslett; Charles N. Aprill; Barry McDonald; Sharon B. Young

2005-01-01

145

Failure loads of mechanical fastened pinned and bolted composite joints with two serial holes  

Microsoft Academic Search

An experimental and numerical study has been carried out to investigate the first failure load and the bearing strength behavior of pinned joints of glass fiber reinforced woven epoxy composite prepregs with two serial holes subjected to traction forces by two serial rigid pins. In the experiments, a number of parameters such as the edge distance-to- upper hole diameter (E\\/D),

Mustafa Ozen; Onur Sayman

2011-01-01

146

A GUI for a Software that Analyses a Composite Bolted Joint  

Microsoft Academic Search

FastComp is a computational tool for the determi- nation of the forces that a composite bolted joint subjected to multiaxial loads supports until failure occurs. The main inten- tion of the present work was the development of a graphical user interface (GUI) for the referred tool that allows its parameteriza- tion and the visualization of its output results. Using VTK

Patrícia Gonçalves; João Manuel R. S. Tavares

2008-01-01

147

Bolted double-lap composite joints under mechanical and thermal loading  

Microsoft Academic Search

This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts

V. Kradinov; A. Barut; E. Madenci; D. R. Ambur

2001-01-01

148

Optimum design of bolted composite lap joints under mechanical and thermal loading  

Microsoft Academic Search

A new approach is developed for the analysis and design of mechanically fastened composite lap joints under mechanical and thermal loading. Based on the combined complex potential and variational formulation, the solution method satisfies the equilibrium equations exactly while the boundary conditions are satisfied by minimizing the total potential. This approach is capable of modeling finite laminate planform dimensions, uniform

Vladimir Yurievich Kradinov

2003-01-01

149

Secondary bending in multi fastener, composite-to-aluminium single shear lap joints  

Microsoft Academic Search

A novel technique to study secondary bending due to the eccentric load path in single shear, composite-to-aluminium lap joints has been developed and used in a parametric study. The method is based on the specimen curvature, which is derived from lateral displacements of the surface. The lateral displacements are measured with an optical measurement system or calculated with the finite

Johan Ekh; Joakim Schön; L. Gunnar Melin

2005-01-01

150

Development of Rotary Joint Sensor using Ionic Polymer Metallic Composites (IPMC)  

Microsoft Academic Search

Ionic Polymer Metallic Composite (IPMC) is a type of smart material that has been proposed for use as a rotary joint sensor. Previous studies have identified the sensing properties of IPMC that would be useful for this purpose, but the testing methods are still inadequate, and more work needs to be carried out so that IPMC sensors can be used

Jian Chew; Aidan van den Hurk

151

Joint Composition: The Collaborative Letter Writing of a Scribe and His Client in Mexico.  

ERIC Educational Resources Information Center

Presents a detailed description of a scribe and his client in Mexico producing a letter through "joint composition," a term used to refer to letter-writing episodes involving two or more active participants. Shows how the participants negotiated their points of view and pooled their knowledge to produce a specific type of document. (PA)

Kalman, Judy

1996-01-01

152

Application of the point stress criterion to the failure of composite pinned joints  

Microsoft Academic Search

An analysis was performed to evaluate the bearing strength of pin-loaded composite joints using a two parameter characteristic curve model. This model involves determination of characteristic dimensions in tension and compression and based on this model, a two-dimensional stress analysis was used to determine the stress distribution around the fastener hole. In this analysis, characteristic dimensions in tension and compression

H. A. Whitworth; O. Aluko; N. A. Tomlinson

2008-01-01

153

Stacking Sequence Effects on Fatigue Intra-laminar Damage Progression in Composite Joints  

NASA Astrophysics Data System (ADS)

In this paper the effects of the stacking sequence on the fatigue intra-laminar damage accumulation in pinned composite joints is investigated. A fatigue damage propagation numerical model based on gradual material degradation rules and Hashin fatigue failure criteria is formulated, implemented in a finite element platform and then used to simulate the intra-laminar fatigue damage evolution in the analysed composite joints. The model has been preliminary validated against literature experimental data in terms of s-n curves providing confirmation of its effectiveness in predicting the joints fatigue life. Different stacking sequences: zero-dominated, quasi-isotropic, cross-ply with different 0 ° and 90 ° plies distributions, have been considered when investigating the influence of the stacking sequence on the fatigue behaviour of the joints. The simulation of the joints' fatigue life provided detailed information on the intra-laminar damage mechanisms on-set and evolution related to fatigue gradual degradation of material stiffness and strength for different values of the applied maximum stresses.

Riccio, A.; Mozzillo, G.; Scaramuzzino, F.

2013-06-01

154

Ultrasonic guided wave monitoring of composite wing skin-to-spar bonded joints in aerospace structures  

NASA Astrophysics Data System (ADS)

The monitoring of adhesively bonded joints by ultrasonic guided waves is the general topic of this paper. Specifically, composite-to-composite joints representative of the wing skin-to-spar bonds of unmanned aerial vehicles (UAVs) are examined. This research is the first step towards the development of an on-board structural health monitoring system for UAV wings based on integrated ultrasonic sensors. The study investigates two different lay-ups for the wing skin and two different types of bond defects, namely poorly cured adhesive and disbonded interfaces. The assessment of bond state is based on monitoring the strength of transmission through the joints of selected guided modes. The wave propagation problem is studied numerically by a semi-analytical finite element method that accounts for viscoelastic damping, and experimentally by ultrasonic testing that uses small PZT disks preferably exciting and detecting the single-plate s0 mode. Both the models and the experiments confirm that the ultrasonic energy transmission through the joint is highly dependent on the bond conditions, with defected bonds resulting in increased transmission strength. Large sensitivity to the bond conditions is found at mode coupling points, as a result of the large interlayer energy transfer.

Matt, Howard; Bartoli, Ivan; Lanza di Scalea, Francesco

2005-10-01

155

Stress and failure analysis of mechanically fastened joints in composite laminates  

Microsoft Academic Search

The literature published on single mechanically fastened joints in fiber-reinforced plastics is reviewed. A finite-element model is developed to predict the response of pin-loaded composite plates. The model takes into account contact at the pin–hole interface, progressive damage, large deformation theory, and a non-linear shear stress–strain relationship. To predict the progressive ply failure, the analysis combines Hashin and the maximum

Marie-Laure Dano; Guy Gendron; André Picard

2000-01-01

156

Singular stress fields near contact boundaries in a composite bolted joint  

Microsoft Academic Search

Singular stresses arising in the neighborhood of contact surfaces introduced in laminated orthotropic plates by mechanical joining with clamp-up were investigated by using local asymptotic solutions and full-field numerical analysis. Three-dimensional B-spline approximation of the displacements and a penalty function-based contact solution was used in the numerical analysis. Recent work has shown that fracture in bolted composite joints may initiate

T. J. Whitney; E. V. Iarve; R. A. Brockman

2004-01-01

157

Carbon nanotube-based health monitoring of mechanically fastened composite joints  

Microsoft Academic Search

The onset of local damage in joints, such as delamination, cracking and fastener loosening can often be difficult to detect and has long-term implications on the performance of the structure. As the use of advanced fiber composites expands in large-scale structural applications, where joining of large structural members using adhesives and\\/or mechanical fasteners are employed, these connections represent a potential

Erik T. Thostenson; Tsu-Wei Chou

2008-01-01

158

Fatigue failure characterisation of resistance-welded thermoplastic composites skin\\/stringer joints  

Microsoft Academic Search

An experimental investigation characterising the fatigue failure mechanisms of resistance-welded thermoplastic composites skin\\/stringer joints is presented. Unidirectional (UD) and quasi-isotropic adherends were welded using stainless steel meshes as heating elements. The specimen geometry consisted of a flange laminate, representing a stringer, welded onto a skin laminate. In order to avoid current leakage to the electrically conductive adherends, a ceramic-coated heating

M. Dubé; P. Hubert; A. Yousefpour; J. Denault

2009-01-01

159

Fatigue in mechanically fastened composite and metallic joints; Proceedings of the Symposium, Charleston, SC, Mar. 18, 19, 1985  

SciTech Connect

The present conference considers advanced fastener technology for composite and metallic joints, a fatigue life-enhancing and high interference bushing installation employing the 'ForceMate' technique, fatigue life improvement by cold working fastener holes in 7050 aluminum alloy, the fatigue strength of bolted and adhesively bonded structural steel joints, and the effect of load transfer on the fatigue of mechanically fastened metallic joints. Also discussed are the evaluation of a stochastic initial fatigue quality model for fastener holes, the experimental characterization of cracks at open holes and in rounded-end straight attachment lugs, the fatigue of riveted metallic joints, an enhanced stop-drill repair procedure for cracked structures, the influence of fastener flexibility on load transfer and fatigue life prediction in multiple row joints, the strength and lifetime of bolted laminates, and the fatigue of bolted continuous-fiber/sheet-molding-compound composite-metal joints.

Potter, J.M.

1986-01-01

160

Custom fabrication of composite tibial hemi-knee joint combining CAD/CAE/CAM techniques.  

PubMed

A custom fabrication approach combining computer-aided design (CAD), computer-aided engineering (CAE), and computer-aided manufacturing (CAM) techniques for constructing a novel composite tibial hemi-knee joint is presented. Anatomical modelling was used to provide the computer model with specific geometry for individuals and the finite element method (FEM) was adopted to understand the loading distribution on each component of the composite substitute. Rapid prototyping (RP) was employed to build the negative patterns, based on which the titanium alloy tibial tray and the porous artificial bone were custom fabricated through quick casting and powder sintering techniques. The results show that the titanium alloy component bears most of the loading while the artificial bone shares little, which could prevent it from fracturing in vivo. The final porous artificial bone has controllable microchannels (600 microm) and random micropores (100-200 microm), which ensures full interconnectivity and is expected to address the biological consideration. Clinical application demonstrates that the composite tibial hemi-knee joint has enough mechanical strength and can fit with the upper hemi-knee joint. This novel approach provides a new way to repair large bone defects in the loading sites. PMID:17236516

He, Jiankang; Li, Dichen; Lu, Bingheng; Wang, Zhen; Tao, Zhang

2006-11-01

161

Thermal expansion behavior and performance of VLP diffusion-bonded joints of SiC p\\/A356 composites  

Microsoft Academic Search

Effects of the bonding thermal cycle and heat treatment on thermal expansion behaviors and mechanical performance of SiCp\\/A356 composites and their joints were investigated. Joints were made by using the vibration liquid phase (VLP) diffusion bonding process, and treated by the solution and aging. It has been found that the CTE of the base metal is not significantly influenced by

Zhiwu Xu; Jiuchun Yan; Weiwei Zhao; Huibin Xu; Shiqin Yang

2005-01-01

162

Fatigue in mechanically fastened composite and metallic joints; Proceedings of the Symposium, Charleston, SC, Mar. 18, 19, 1985  

Microsoft Academic Search

The present conference considers advanced fastener technology for composite and metallic joints, a fatigue life-enhancing and high interference bushing installation employing the 'ForceMate' technique, fatigue life improvement by cold working fastener holes in 7050 aluminum alloy, the fatigue strength of bolted and adhesively bonded structural steel joints, and the effect of load transfer on the fatigue of mechanically fastened metallic

1986-01-01

163

Finite difference three-dimensional solution of stresses in adhesively bonded composite tubular joint subjected to torsion  

Microsoft Academic Search

Traditionally, the adhesive layer in adhesively bonded joints is simplified as having constant shear and peel stresses across the thickness. In this study, it is modeled as a separate 3D elastic body without the uniform stress assumption. The stress state in an adhesively bonded fiber-reinforced composite tubular joint subjected to a torsional load is theoretically analyzed. A finite difference method

Wei Xu; Guoqiang Li

2010-01-01

164

A study of failure in bonded lap joints using fracture mechanics  

NASA Astrophysics Data System (ADS)

Although adhesively bonded lap joint has already been widely applied in structures, the strength prediction of the joint is still a challenge. Among many parameters which affect the failure load of the lap joint, the adhesive layer thickness is a very important one. In this study, fracture mechanics is used to analyze the failure mechanism of the lap joint and evaluate the thickness effect on strength of the lap joint. Generally, the adhesive material is softer than the substrates and the crack in the adhesive layer is constrained by the rigid boundaries. The stress field is changed due to the effect of the rigid boundaries. For linear elastic material, the K-Dominance zone is highly reduced and the traditional constant stress intensity factor prediction over-predicts the failure load of the specimens. Constant effective fracture toughness is proposed for better strength prediction by considering of the non-singular stress term ahead of the crack tip. For elastic-plastic material, CTOA is proven to be insensitive to the constraining of the rigid boundaries and can be used as the failure criterion for fracture analysis. Both experimental and FEA simulation show that constant CTOA criterion well predicts the adhesive thickness effect on strength of the DCB specimens for mode I fracture failure. The failure initiation mode of single lap joint is analyzed and the constant CTOA criterion is also proven to be capable to prediction the strength of single lap joint.

Qian, Haiyang

165

Stress and strength analysis of composite joints using direct boundary element method  

NASA Astrophysics Data System (ADS)

The stress distribution and the strength of bolted joints of orthotropic composite plates under uniform loading are investigated. A direct boundary element method with quadratic isoparametric elements in conjunction with a fundamental solution derived by Rizzo and Shippy (1970) is used. Plates with rigid bolts are treated as 2D plane stress problems, and the bolt size is considered to be identical to the hole dimension. The prediction of the laminate strength is based on the Yamada-Sun (1978) failure criterion. Some numerical results for various edge distances and material properties are presented for illustrative purposes.

Lin, Chien-Chang; Lin, Chuen-Horng

166

Some studies on evaluation of degradation in composite adhesive joints using ultrasonic techniques.  

PubMed

Experimental and theoretical studies on degradation of composite-epoxy adhesive joints were carried out on samples having different interfacial and cohesive properties. Oblique incidence ultrasonic inspection of bonded joints revealed that degradation in the adhesive can be measured by significant variation in reflection amplitude as also by a shift in the minima of reflection spectrum. It was observed that severe degradation of the adhesive leads to failure dominated by interfacial mode. Through this investigation it is demonstrated that a correlation exists between the bond strength and a frequency shift in reflection minimum. The experimental data was validated using analytical models. Though both bulk adhesive degradation and interfacial degradation influences the shift in spectrum minimum, the contribution of the latter was found to be significant. An inversion algorithm was used to determine the interfacial transverse stiffness using the experimental oblique reflection spectrum. The spectrum shift was found to depend on the value of interfacial transverse stiffness using which a qualitative assessment can be made on the integrity of the joint. PMID:23541960

Vijaya Kumar, R L; Bhat, M R; Murthy, C R L

2013-03-07

167

Analytical Modeling of ASTM Lap Shear Adhesive Specimens.  

National Technical Information Service (NTIS)

An analytical model was developed to predict the stress distribution within the specimen specified in ASTM D 3165 'Strength Properties of Adhesives in Shear by Tension Loading of Single-Lap-Joint Laminated Assemblies.' In the developed model, the composit...

C. Yang J. S. Tomblin Z. Guan

2003-01-01

168

A Multi-Objective Advanced Design Methodology of Composite Beam-to-Column Joints Subjected to Seismic and Fire Loads  

SciTech Connect

A multi-objective advanced design methodology dealing with seismic actions followed by fire on steel-concrete composite full strength joints with concrete filled tubes is proposed in this paper. The specimens were designed in detail in order to exhibit a suitable fire behaviour after a severe earthquake. The major aspects of the cyclic behaviour of composite joints are presented and commented upon. The data obtained from monotonic and cyclic experimental tests have been used to calibrate a model of the joint in order to perform seismic simulations on several moment resisting frames. A hysteretic law was used to take into account the seismic degradation of the joints. Finally, fire tests were conducted with the objective to evaluate fire resistance of the connection already damaged by an earthquake. The experimental activity together with FE simulation demonstrated the adequacy of the advanced design methodology.

Pucinotti, Raffaele [Department of Mechanics and Materials, Mediterranean University of Reggio Calabria, loc. Feo di Vito, Reggio Calabria, 89126 (Italy); Ferrario, Fabio; Bursi, Oreste S. [Department of Mechanical and Structural Engineering, University of Trento, via Mesiano 7, Trento, 38050 (Italy)

2008-07-08

169

A Multi-Objective Advanced Design Methodology of Composite Beam-to-Column Joints Subjected to Seismic and Fire Loads  

NASA Astrophysics Data System (ADS)

A multi-objective advanced design methodology dealing with seismic actions followed by fire on steel-concrete composite full strength joints with concrete filled tubes is proposed in this paper. The specimens were designed in detail in order to exhibit a suitable fire behaviour after a severe earthquake. The major aspects of the cyclic behaviour of composite joints are presented and commented upon. The data obtained from monotonic and cyclic experimental tests have been used to calibrate a model of the joint in order to perform seismic simulations on several moment resisting frames. A hysteretic law was used to take into account the seismic degradation of the joints. Finally, fire tests were conducted with the objective to evaluate fire resistance of the connection already damaged by an earthquake. The experimental activity together with FE simulation demonstrated the adequacy of the advanced design methodology.

Pucinotti, Raffaele; Ferrario, Fabio; Bursi, Oreste S.

2008-07-01

170

Testing of composite steel top-and-seat-and-web angle joints at ambient and elevated temperatures, Part 1: Ambient tests  

Microsoft Academic Search

This paper presents six ambient tests on composite steel top-and-seat-and-web (TSW) angle joint specimens subject to monotonic loading. It is well known that the inherent strength and stiffness of composite semi-rigid joints can improve the structural behaviour of steel frame structures. However, experimental works on the composite steel TSW angle joints are very limited. The main objective of this study

Zhen Yuan; Kang Hai Tan; Seng Kiong Ting

2011-01-01

171

Testing of composite steel top-and-seat-and-web angle joints at ambient and elevated temperatures: Part 2 — Elevated-temperature tests  

Microsoft Academic Search

An experimental programme of eight elevated-temperature tests on composite steel top-and-seat-and-web (TSW) angle joints was carried out to investigate the behaviour of this form of joints under fire conditions. It is found that the inherent strength and stiffness of composite joints can significantly improve the structural behaviour of steel framed structures under fire conditions. However, experimental works on composite steel

Zhen Yuan; Kang Hai Tan; Seng Kiong Ting

2011-01-01

172

Peel ply surface treatment for composite assemblies: Chemistry and morphology effects  

Microsoft Academic Search

Glass\\/epoxy and carbon\\/epoxy composites were manufactured using a series of polyester and polyamide based peel ply treatments. The influence of peel ply removing upon surface characteristics was assessed with performing contact angle measurements, laser profilometry, SEM and ToF-SIMS analysis.The surface properties of the composite material prior to bonding and the single lap shear performances of resulting assemblies were compared, in

Q. Bénard; M. Fois; M. Grisel

2005-01-01

173

Methodology for optimal configuration in structural health monitoring of composite bonded joints  

NASA Astrophysics Data System (ADS)

In this study, a structural health monitoring (SHM) strategy is proposed in order to detect disbonds in a composite lap-joint. The structure under study is composed of a carbon fiber reinforced polymer (CFRP) bonded to a titanium plate and artificial disbonds are simulated by inserting Teflon tapes of various dimensions within the joint. In situ inspection is ensured by piezoceramics bonded to the structure to generate and measure guided waves. Theoretical propagation and through-thickness stress distribution are first studied in order to determine damage sensitivity with respect to the mode and frequency of the generated guided wave. The optimal configuration of the system in terms of piezoceramic size, shape and inter-unit spacing is then validated using finite element modeling (FEM) in 3D. Experimental assessment of propagation characteristics is conducted using laser Doppler vibrometer (LDV) in order to justify theoretical and numerical assumptions and pitch-catch measurements are then performed to validate the efficient detection of the damage and accurate estimation of its size.

Quaegebeur, N.; Micheau, P.; Masson, P.; Castaings, M.

2012-10-01

174

Analytical and experiment study of clearance and bearing-bypass load effects in composite bolted joints  

SciTech Connect

A combined analytical and experimental study is conducted to determine the effects of clearance and bearing-bypass loading for mechanically fastened joints in composites. A simple method of analysis is developed to account for the nonlinear effects of bolt-hole clearance. The nonlinear load-contact variations for clearance-fit fasteners are also measured using specially instrumented fastener. For a quasi-isotropic graphite/epoxy laminate, results show that the contact arc as well as the peak stresses around the hole and their locations are strongly influenced by the clearance. After a slight initial nonlinearity, the peak stresses vary linearly with applied load. The typical clearance levels are shown to have only a minor influence on the overall joint stiffness. Quasi-isotropic graphite/epoxy laminates (T300/5208) were tested under combined bearing and bypass loading to study failure modes and strengths. Radiographs were made after damage onset and after ultimate load to examine the failure criteria to analyze the test data. The near the bolt-hole are calculated for each test condition, and then used with appropriate failure criteria to analyze the test data. The tension data show a linear interaction for combined bearing and bypass loading with damage developing the net-tension mode and growing to failure in the same mode. Failure modes are more complex in compression.

Naik, R.V.A.

1986-01-01

175

A compact analytic method for stress distribution in composite pinned joints  

NASA Astrophysics Data System (ADS)

An analysis was performed to evaluate the stress distribution in composite pin loaded joints. In this analysis involving a push fit pin, the pin was modeled as rigid and the plate as an infinite orthotropic plate. The analysis involves first the specification of displacement expressions in form of a trigonometric series that satisfy the boundary conditions for the contact region in terms of a set of undetermined coefficients. Based on this assumed distribution, the Lekhnitskii complex variable approach is used to obtain the stress functions needed to evaluate the contact stress within the joint. Unknown coefficients in the displacement expression were obtained by assuming coulomb friction within the contact region and then evaluating the displacement at discrete points within this region. Material properties of carbon fiber reinforced plastic laminates and a graphite-epoxy laminate was used for the study and the stress distribution for various values of coefficient of friction analyzed and the results compared with the previous investigations. This analysis reveals that friction has a pronounced effect on stress distribution around the hole boundary.

Aluko, Olanrewaju

176

Finite element analysis of laminated composite plates with multi-pin joints considering friction  

NASA Astrophysics Data System (ADS)

The problems in multi-pin joints of laminated composite plates are analyzed, considering the friction effects in the contact boundary. The coulomb friction law is used and the contact constraint are handled by extended interior penalty methods. The perturbed variational principle is adopted to treat the non-differential term due to the coulomb friction, and the obtained equilibrium equation is discretized by the finite element method. The normal contact pressures and the tangential forces due to the frictional effect in the contact area are obtained by the penalty term without the increment of the number of unknowns. Numerical experiments confirm that the formulation using adopting the extended interior penalty and the regularization process for the non-differentiable term is mathematically sound and numerically efficient.

Kim, Seung Jo; Kim, Jin Hee

1995-05-01

177

Contents and compositions of glycosaminoglycans in different sites of the human hip joint cartilage.  

PubMed Central

The distribution of glycosaminoglycans (GAGs) in different functional regions (weight-bearing and nonweight-bearing portions) of the human hip joint cartilage was studied. The results obtained were as follows: (1) Weight-bearing cartilage contains larger amounts of GAGs than nonweight-bearing, cartilage. (2) Weight-bearing cartilage contains keratan sulphate in higher ratio to chondroitin sulphate than nonweight-bearing cartilage. (3) The differences in content and composition of GAGs between the weight-bearing and nonweight-bearing portions are more pronounced in the femoral head than in the acetabulum. The preliminary analyses showed that the chondroitin sulphate from the acetabular cartilage contained exclusively 6-sulphated disaccharide units and there was some heterogeneity in keratan sulphate.

Yoshida, K; Azuma, H

1982-01-01

178

Changes in the reflected spectra of embedded chirped fibre Bragg gratings used to monitor disbonding in bonded composite joints  

Microsoft Academic Search

Recent work has outlined a method for health monitoring the structural integrity of adhesively bonded composite joints based on the use of a chirped fibre Bragg grating (CFBG) embedded within an adherend, but not within the glue-line. In this paper, the reflected CFBG spectra for disbonds of different lengths have been predicted with the aid of a finite-element model of

J. Palaniappan; H. Wang; S. L. Ogin; A. M. Thorne; G. T. Reed; A. D. Crocombe; Y. Rech; S. C. Tjin

2007-01-01

179

Comparison of the bony ingrowth into an osteochondral defect and an artificial osteochondral composite device in load-bearing joints  

Microsoft Academic Search

In order to preserve as much subchondral cancellous bone as possible in the repair of damaged joint surfaces, we have attempted to develop an artificial articular cartilage, using polyvinyl alcohol hydrogel, a rubber-like gel. In this study, osteochondral defects were made and an osteochondral composite device was implanted in the weight-bearing portions of medial and lateral femoral condyles of dogs.

Y.-S. Chang; H.-O. Gu; M. Kobayashi; M. Oka

1998-01-01

180

Assessment of a Friction Joint Concept for the Roadwheel Housing Attachment of the Composite Infantry Fighting Vehicle.  

National Technical Information Service (NTIS)

Evaluation of a friction joint concept was undertaken to assess its viability as a critical joining techniques for the Composite Infantry Fighting Vehicle. Through thickness viscoelastic relaxation effects of the thick (0/90/ 45) S2 glass/polyester woven ...

C. Cavallaro K. D. Weight R. B. Dooley S. M. Serabian

1991-01-01

181

Generic element formulation for modelling bolted lap joints  

NASA Astrophysics Data System (ADS)

Joints have significant effects on the dynamic response of the assembled structures due to existence of two non-linear mechanisms in their interface, namely slipping and slapping. These mechanisms affect the structural response by adding considerable damping into the structure and lowering the natural frequencies due to the stiffness softening. Neglecting these effects in modelling of joints produces errors in predictions of the structure responses. In this paper, a non-linear generic element formulation is developed for modelling bolted lap joints. The generic element is formed by satisfying all conditions that are known for a joint interface and hence providing a non-linear parametric formulation for the families of allowable joint models. Dynamic response of the developed model for the assembled structure including the generic joint interface element is obtained using the incremental harmonic balance (IHB) method. The generic parameters of the joint are identified by minimising the difference between the model response obtained from IHB method and the observed behaviour of the structure. The procedure is demonstrated by modelling an actual structure containing a single lap bolted joint in the middle. The frequency responses of the structure around the first two resonance frequencies are measured by exciting the structure using a sinusoidal force at each individual frequency. The measured responses are compared with the predictions of the model containing a parametric generic joint element. The parameters of the joint interface model are successfully identified by minimising the difference between the measured responses and the model predictions.

Ahmadian, Hamid; Jalali, Hassan

2007-07-01

182

A statistical approach to the analysis of ultimate strengths of bolted joints in laminated composites  

Microsoft Academic Search

The general linear models (GLM) routine in the statistical software package SAS has been utilized to develop a statistical model for the prediction of joint failure in single-shear joints in IM7\\/8551 graphite\\/epoxy laminates on the basis of the results of an extensive bolted-joint strength testing program. Ultimate joint strength values from the experimental study were utilized as input for the

K. C. Schulz; H. J. Hietala; P. F. Packman

1996-01-01

183

Dynamic shear strength of adhesive joints made of metallic and composite adherents  

Microsoft Academic Search

The use of adhesive joints has gained good acceptance in the automotive and aerospace industries in recent years, particularly for joining glass fiber reinforced plastics (GFRP) to metals. Such joints will be subjected to short duration dynamic loads in service. The present study focuses on the evaluation of the shear strength of adhesive joints prepared using four different commercial adhesives

Sohan Lal Raykhere; Prashant Kumar; R. K. Singh; Venkitanarayanan Parameswaran

2010-01-01

184

Characteristics of plasma surface treated composite adhesive joints at high environmental temperature  

Microsoft Academic Search

When an adhesive joint is exposed to high environmental temperature, the load transmission capability of the adhesive joint decreases because the stiffness and strength of structural adhesive decrease. The load transmission capability of adhesive joint at high environmental temperature can be improved by increasing the surface free energy of adherends with surface pretreatments.In this paper, a capacitively coupled radio frequency

Jin Kook Kim; Dai Gil Lee

2002-01-01

185

Treatment of Unsymmetric Adhesively Bonded Composite Sandwich Panels-To-Flange Joints  

Microsoft Academic Search

An analytical solution for the determination of stresses in unsymmetric adhesively bonded joints is presented. The classical sandwich plate theory and an adhesive interface constitutive model are employed for this development. In addition, an analytical solution for the consideration of the effect of fracture in the joints, using the modified crack closure also is developed. Joints with various configurations (symmetrical

F. TAHERI; G. P. ZOU

2004-01-01

186

Mechanism of electromigration-induced failure in the 97Pb-3Sn and 37Pb-63Sn composite solder joints  

NASA Astrophysics Data System (ADS)

The electromigration-induced failure in the composite solder joints consisting of 97Pb-3Sn on the chip side and 37Pb-63Sn on the substrate side was studied. The under-bump metallization (UBM) on the chip side was 5 ?m thick electroplated Cu coated on sputtered TiW/Cu and on the substrate side was electroless Ni/Au. It was observed that failure occurred in joints in a downward electron flow (from chip to substrate), while those joints having the opposite current polarity showed only minor changes. During electromigration, in addition to the compositional change by the moving of Pb atoms in the same direction as the electrons, current crowding was observed inside the UBM and it enhanced the phase transformation of Cu to Cu3Sn and to Cu6Sn5 at the UBM/solder interface. Due to the growth of Cu6Sn5, the Cu UBM was consumed rapidly, resulting in void formation-induced failure at the cathode side. The Cu6Sn5 intermetallic compound and void were first initiated from the upper left-hand side corner of the contact window which matches the current crowding region. The sequence of Cu UBM consumption and void formation is presented. The current crowding has been confirmed by simulation. The mechanism of electromigration-induced failure in the composite solder joint structure is discussed.

Nah, J. W.; Paik, K. W.; Suh, J. O.; Tu, K. N.

2003-12-01

187

Thermal analysis for resistance welding of large-scale thermoplastic composite joints  

SciTech Connect

The need for effective and reliable joining methods continues to grow as the use of thermoplastic composites becomes widespread. It is now possible to join large-scale components with the development of an automated sequential resistance welding process. The thermal history generated by the heating element placed at the interface between adherends determines the quality and performance of the welded joint. This article presents a thermal analysis for the resistance welding of large-scale components that overcomes the limitations of previous models. To simulate welding of the interface, a heat generation term was incorporated that accounts for the Joule heating of graphite fibers in the heating element. A parametric study was conducted to investigate the influence of welding parameters and assess the uniformity of interface temperatures. Components were joined by the resistance welding process to obtain experimental verification. Regions of localized overheating where potential current leakage may occur were identified as a function of process parameters. Insights on promoting more uniform heating for the resistance welding process are discussed. 11 refs.

Holmes, S.T.; Gillespie, J.W. Jr. (Delaware Univ., Newark (United States))

1993-06-01

188

Thermal analysis for resistance welding of large-scale thermoplastic composite joints  

NASA Astrophysics Data System (ADS)

The need for effective and reliable joining methods continues to grow as the use of thermoplastic composites becomes widespread. It is now possible to join large-scale components with the development of an automated sequential resistance welding process. The thermal history generated by the heating element placed at the interface between adherends determines the quality and performance of the welded joint. This article presents a thermal analysis for the resistance welding of large-scale components that overcomes the limitations of previous models. To simulate welding of the interface, a heat generation term was incorporated that accounts for the Joule heating of graphite fibers in the heating element. A parametric study was conducted to investigate the influence of welding parameters and assess the uniformity of interface temperatures. Components were joined by the resistance welding process to obtain experimental verification. Regions of localized overheating where potential current leakage may occur were identified as a function of process parameters. Insights on promoting more uniform heating for the resistance welding process are discussed.

Holmes, Scott T.; Gillespie, John W., Jr.

1993-06-01

189

Effect of filler metal composition on the strength of yttria stabilized zirconia joints brazed with Pd-Ag-CuOx  

SciTech Connect

The Ag-CuOx system is of interest to be used to be used as an air braze filler metal for joining high temperature electrochemical devices. Previous work has shown that the melting temperatures can be increased by adding palladium to Ag-CuOx and it is expected that this may aid high temperature stability. This work compares the room temperature bend strength of joints made between yttria-stabilized zirconia (YSZ) air brazed using Ag-CuOx without palladium and with 5 and 15mol% palladium additions. It has been found that in general palladium decreases joint strength, especially in low copper oxide compositions filler metals. At high copper oxide contents, brittle fracture through both copper oxide rich phases and the YSZ limits joint strength.

Darsell, Jens T.; Weil, K. Scott

2008-09-08

190

Use of high and low frequency dielectric measurements in the NDE of adhesively bonded composite joints  

NASA Astrophysics Data System (ADS)

Dielectric spectroscopy has been developed as a non-destructive technique for assessment of moisture content and structural integrity of adhesively bonded joints. Knowledge of these parameters is particularly crucial for the aerospace industry, since environmental degradation of adhesive joints presents a major limit on their utilization. High and low frequency measurements have been carried out on joints assembled from CFRP adherend, and a commercially available adhesive (AF 163-2K). The samples have been aged in deionised water at 75oC to chart the effect water ingress has on bond durability. In addition, some joints have been exposed to cryogenic temperatures to mimic the conditions joints experience whilst an aircraft is in flight. In this way it has been possible to determine the extent of degradation caused by freezing of water within the joint structure. Dielectric behaviour of the joints was studied in both the frequency and in the time domain. Frequency domain analysis allows the amount and effects of moisture ingress in the bondline to be assessed, whereas the time domain highlights the onset of joint defects with increasing exposure time. Mechanical testing of the joints has been carried out to enable correlation between changes in strength and failure mechanism due to moisture ingress, with changes in the dielectric data. In addition, dielectric studies of the neat adhesive have been undertaken, as have gravimetric and dynamic mechanical thermal analysis. These have helped reveal the effects of ageing upon the adhesive layer itself.

Pethrick, R. A.; Hayward, D.; McConnell, B. K.; Crane, R. L.

2005-05-01

191

Combined in-plane and through-the-thickness analysis for failure prediction of bolted composite joints  

Microsoft Academic Search

Although two-dimensional methods provide accurate predictions of contact stresses and bolt load distribution in bolted composite joints with multiple bolts, they fail to capture the effect of thickness on the strength prediction. This study presents an analysis method to account for the variation of stresses in the thickness direction by augmenting a two-dimensional analysis with a one-dimensional through-the-thickness analysis. The

V. Kradinov; E. Madenci; D. R. Ambur

2007-01-01

192

Post-earthquake fire and seismic performance of welded steel–concrete composite beam-to-column joints  

Microsoft Academic Search

The performance of steel–concrete composite full strength joints endowed with concrete filled tubes, designed with a multi-objective methodology dealing with seismic actions followed by fire is presented in this paper. In detail, instead of a traditional single-objective design where fire safety and seismic safety are independently achieved and the sequence of seismic and fire loading are not taken into account,

R. Pucinotti; O. S. Bursi; J. F. Demonceau

2011-01-01

193

SNARE complexes of different composition jointly mediate membrane fusion in Arabidopsis cytokinesis.  

PubMed

Membrane fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes. Although membrane fusion is required for separating daughter cells in eukaryotic cytokinesis, the SNARE complexes involved are not known. In plants, membrane vesicles targeted to the cell division plane fuse with one another to form the partitioning membrane, progressing from the center to the periphery of the cell. In Arabidopsis, the cytokinesis-specific Qa-SNARE KNOLLE interacts with two other Q-SNAREs, SNAP33 and novel plant-specific SNARE 11 (NPSN11), whose roles in cytokinesis are not clear. Here we show by coimmunoprecipitation that KNOLLE forms two SNARE complexes that differ in composition. One complex is modeled on the trimeric plasma membrane type of SNARE complex and includes, in addition to KNOLLE, the promiscuous Qb,c-SNARE SNAP33 and the R-SNARE vesicle-associated membrane protein (VAMP) 721,722, also involved in innate immunity. In contrast, the other KNOLLE-containing complex is tetrameric and includes Qb-SNARE NPSN11, Qc-SNARE SYP71, and VAMP721,722. Elimination of only one or the other type of KNOLLE complex by mutation, including the double mutant npsn11 syp71, causes a mild or no cytokinesis defect. In contrast, the two double mutants snap33 npsn11 and snap33 syp71 eliminate both types of KNOLLE complexes and display knolle-like cytokinesis defects. Thus the two distinct types of KNOLLE complexes appear to jointly mediate membrane fusion in Arabidopsis cytokinesis. PMID:23515225

El Kasmi, Farid; Krause, Cornelia; Hiller, Ulrike; Stierhof, York-Dieter; Mayer, Ulrike; Conner, Laura; Kong, Lingtian; Reichardt, Ilka; Sanderfoot, Anton A; Jürgens, Gerd

2013-03-20

194

Investigation of optimal surface treatments for carbon\\/epoxy composite adhesive joints  

Microsoft Academic Search

Although an adhesive joint can distribute the load over a larger area than a mechanical joint, requires no holes, adds very little weight to the structure and has superior fatigue resistance, but it not only requires a careful surface preparation of the adherends but also is affected by service environments. In this paper, suitable conditions for surface treatments such as

Jin Kook Kim; Hak Sung Kim; Dai Gil Lee

2003-01-01

195

Effect of alloying armco iron on the properties of composite joints  

Microsoft Academic Search

In order to obtain high-quality welded joints between aluminum and its alloys and various types of steel, we resort to the preliminary coating of the steel with zinc, aluminum, or other metal. Ryabov [1] has shown how the various forms of zinc coating affect the properties and thickness of the diffusion zone which determines the strength of the welded joints.

V. R. Ryabov; V. I. Yumatova; A. P. Butnik

1973-01-01

196

Electromigration and thermomigration studies in composite high lead and eutectic tin-lead flip chip solder joint  

NASA Astrophysics Data System (ADS)

The effect of thermomigration and the combination effect of thermomigration and electromigration have been studied in composite SnPb flip chip solder joints. Because Al line on the silicon chip side is the major heat source exerted on flip chip solder joint, temperature gradient across the joint is induced when a long Al line is stressed with high current density. Under a estimated temperature gradient of 1000°C/cm, Sn-rich and Pb-rich phase separation is found to occur. Experimental results have shown that Sn-rich phase accumulates at the hot side and Pb-rich phase accumulates at the cold side after thermomigration. When solder bumps are current high current density, thermomigration was found to accompany electromigration. Not only Pb-rich phase migrated toward the anode side and Sn-rich phase migrated toward the cathode side due to electromigration, Sn-rich phase was found to migrate along the top of solder joint due to thermomigration. It was found that as void propagates along the top of the solder joint, current crowding region shifts with the tip of the void. This created a local hot spot and thus a lateral temperature gradient was induced for thermomigration to occur. To isolate the thermal effect from the current effect, ac stressing at 60 Hz was also utilized. Interestingly, ac seems to have an effect other than thermal effect due to the difference in microstructure evolution between pure thermomigration and ac case after stressing. Further investigation at different frequency is needed to fully understand the effect of ac. Furthermore, analysis was performed to explain the phenomena of phase separation and phase reversal in the solder joint considering a constraint volume within underfill. Both Kirkendall effect and back stress were considered. Finally, detail morphological change after thermomigration and electromigration were investigated. Grain refinement was found to occur at a certain stressing condition. Production of entropy and morphological instability were utilized to explain the phenomenon.

Huang, Annie Tzuyu

197

21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.  

Code of Federal Regulations, 2013 CFR

...across-the-joint. This generic type of device includes prostheses that consist of a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular component made of ultra-high molecular weight polyethylene with carbon...

2013-04-01

198

Residual stress distribution in an Al{sub 2}O{sub 3}-Ni joint bonded with a composite layer  

SciTech Connect

Neutron diffraction was used to study the residual stress distribution in an axisymmetric Al{sub 2}O{sub 3}-Ni joint bonded with a 40 vol% Al{sub 2}O{sub 3}-60 vol% Ni composite layer. A series of measurements was taken along the axis of symmetry through the Al{sub 2}O{sub 3} and composite layers. It is shown that after taking into account the finite neutron diffraction sampling volume, both the trends and peak values of the experimental strain distribution were in excellent agreement with calculations of a simple finite element model, where the rule-of-mixtures approach was used to describe the constitutive behavior of the composite interlayer. In particular, the predicted steep strain gradient near the interface was confirmed by the experimental data.

Wang, X.L.; Watkins, T.R. [Oak Ridge National Lab., TN (United States); Rabin, B.H.; Williamson, R.L.; Bruck, H.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1996-07-01

199

The effect of environment on the fatigue of bonded composite joints. Part 1: testing and fractography  

Microsoft Academic Search

In this work, the effect that test environment and pre-conditioning had on the fatigue behaviour of CFRP\\/epoxy lap–strap joints was investigated. It was shown that the fatigue resistance of the lap–strap joints did not vary significantly until the glass transition temperature, Tg, was approached, at which point a considerable reduction in the fatigue threshold load was observed. It was also

I. A Ashcroft; M. M. Abdel Wahab; A. D Crocombe; D. J Hughes; S. J Shaw

2001-01-01

200

Microstructure and mechanical properties of the Si 3N 4\\/42CrMo steel joints brazed with Ag–Cu–Ti + Mo composite filler  

Microsoft Academic Search

The Si3N4 ceramic was joined to 42CrMo steel using Ag–Cu–Ti+Mo composite filler. Effect of Mo particles content on the microstructure and mechanical properties of the joints were investigated. Defect-free joints were received when the Si3N4\\/42CrMo steel joints were brazed with Ag–Cu–Ti+Mo composite filler. The results show that a continuous reaction layer which is composed of TiN and Ti5Si3 was formed

Y. M. He; J. Zhang; Y. Sun; C. F. Liu

2010-01-01

201

Adhesion strength and fatigue life improvement of co-cured composite\\/metal lap joints by silane-based interphase formation  

Microsoft Academic Search

A silane coupling agent, ?-glycidoxypropyltrimethoxysilane (?-GPS), was used to promote the adhesion strength of composite\\/metal joints fabricated by co-cure bonding process. The thin layer of silane interphase between the epoxy resin of the composite and the steel surface was investigated using SEM. The structure and properties of the interphase are presented. The effect of the interphase on the adhesion strength

Won-Seock Kim; Jung-Ju Lee

2007-01-01

202

A linked manipulator with ion-polymer metal composite (IPMC) joints for soft- and micromanipulation  

Microsoft Academic Search

IPMCs are electroactive materials that bend in electric field. This paper describes a linked manipulator using IPMC joints. We argue that this design reduces the control complexity of an IPMC manipulator and increases the precision of the device. The design rationale stems from our theoretical work in material modeling. It suggests that when electrically decoupled short IPMC strips are connected

Maarja Kruusmaa; Andres Hunt; Andres Punning; Mart Anton; Alvo Aabloo

2008-01-01

203

A Stacked-Shell Finite Element Approach for Modelling a Dynamically Loaded Composite Bolted Joint Under in-Plane Bearing Loads  

NASA Astrophysics Data System (ADS)

This paper presents the results of a study into a novel application of the "stacked-shell" laminate modelling approach to dynamically loaded bolted composite joints using the explicit finite element code PAM-CRASH. The stacked-shell approach provides medium-high fidelity resolution of the key joint failure modes, but is computationally much more efficient than full 3D modelling. For this work, a countersunk bolt in a composite laminate under in-plane bearing loading was considered. The models were able to predict the onset of damage, failure modes and the ultimate load of the joint. It was determined that improved debris models are required in order to accurately capture the progressive bearing damage after the onset of joint failure.

Pearce, G. M. K.; Johnson, A. F.; Hellier, A. K.; Thomson, R. S.

2013-03-01

204

Jointly Constraining Upper Mantle Seismic, Thermal and Compositional Structures From Mineral Physics and Seismic Data  

Microsoft Academic Search

The upper mantle velocity structures and thermal and compositional models are important to the understanding of the dynamics and evolution of the mantle. Several phase transformations exist in the upper mantle, and they are sensitive to mantle composition, temperature and chemical interactions between the olivine- and pyroxene- normative components. With the accumulation of in-situ measurements of elastic properties and accurate

Y. Wang; L. Wen; D. Weidner; Y. He

2007-01-01

205

Optimisation of the rivet joints of the CFRP composite material and aluminium alloy  

Microsoft Academic Search

Purpose: The project included analysis of strain, cracking, and failure of riveted joints of plate elements made from the carbon-fibre-reinforced plastics (CFRP) and from the 6061 aluminium alloy. Design\\/methodology\\/approach: The modelled static tensile strength test carried out for the plates from CFRP and from the 6061 aluminium alloy joined with the steel rivet. Computer simulation was carried out with IDEAS

W. Hufenbach; L. A. Dobrza?ski; M. Gude; J. Konieczny; A. Czulak

2007-01-01

206

Custom fabrication of a composite hemi-knee joint based on rapid prototyping  

Microsoft Academic Search

Purpose – To present a custom design and fabrication method for a novel hemi-knee joint substitute composed of titanium alloy and porous bioceramics based on rapid prototyping (RP) and rapid tooling (RT) techniques. Design\\/methodology\\/approach – The three-dimensional (3D) freeform model of a femur bone was reconstructed based on computerized tomography images via reverse engineering and the 3D reconstruction accuracy was

Jiankang He; Dichen Li; Bingheng Lu; Zhen Wang; Tao Zhang

2006-01-01

207

An Iterative Expectation-Maximization Algorithm Based Joint Estimation Approach for CDMA\\/OFDM Composite Radios  

Microsoft Academic Search

In this paper, an innovative frequency domain joint estimation algorithm for synchronization parameter and channel impulse response (CIR) in direct sequence code division multiple access (DS-CDMA) systems is proposed. The algorithm is based on the expectation-maximization (EM) method. It can provide accurate estimation of channel state information and synchronization parameter for a DS-CDMA receiver even with a simple equalization module

Tianqi Wang; Cheng Li; Hsiao-hwa Chen

2008-01-01

208

A Progressive Damage Model for Mechanically Fastened Joints in Composite Laminates  

Microsoft Academic Search

A three-dimensional finite element model is developed to predict damage progression and strength of mechanically fastened joints in carbon fibre-reinforced plastics that fail in the bearing, tension and shear-out modes. The model is based on a three-dimensional finite element model, on a three-dimensional failure criterion and on a constitutive equation that takes into account the effects of damage on the

P. P. Camanho; F. L. Matthews

1999-01-01

209

Joints of carbon fiber-reinforced SiC composites to Ti-alloy brazed by Ag–Cu–Ti short carbon fibers  

Microsoft Academic Search

Ag–Cu–Ti short carbon fibers were used as brazing material to join carbon fiber-reinforced SiC composite and Ti-alloy. The effects of the content of short carbon fibers, brazing temperature and holding time on the shear strength and microstructure of the brazed joints were investigated. The fibers uniformly distribute in the brazing layer of the performed joint and are preferentially oriented in

Guobiao Lin; Jihua Huang; Hong Zhang

2007-01-01

210

21 CFR 888.3490 - Knee joint femorotibial metal/composite non-constrained cemented prosthesis.  

Code of Federal Regulations, 2013 CFR

...cobalt-chromium-molybdenum, and a tibial condylar component or components made of ultra-high molecular weight polyethylene with carbon fibers composite and are intended for use with bone cement (§ 888.3027). (b) Classification. Class...

2013-04-01

211

Body Composition in Relation to Muscle Strength and Range of Joint Motion.  

National Technical Information Service (NTIS)

The data on 27 body composition, anthropometric and physical performance items were obtained from 45 male subjects and the interrelationships among these measures investigated. Many statistically significant (p = .05) zero-order correlations were found be...

L. L. Laubach

1969-01-01

212

Construction of tissue-engineered osteochondral composites and repair of large joint defects in rabbit.  

PubMed

In this study, a novel three-dimensional (3D) heterogeneous/bilayered scaffold was constructed to repair large defects in rabbit joints. The scaffold includes two distinct but integrated layers corresponding to the cartilage and bone components. The upper layer consists of gelatin, chondroitin sulphate and sodium hyaluronate (GCH), and the lower layer consists of gelatin and ceramic bovine bone (GCBB). The two form a 3D bilayered scaffold (GCH-GCBB), which mimics the natural osteochondral matrix for use as a scaffold for osteochondral tissue engineering. The purpose of this study was to evaluate the efficacy of this novel scaffold, combined with chondrocytes and bone marrow stem cells (BMSCs) to repair large defects in rabbit joints. Thirty-six large defects in rabbit femoral condyles were created; 12 defects were treated with the same scaffold combined with cells (group A); another 12 defects were treated with cell-free scaffolds (group B); the others were untreated (group C). At 6 and 12?weeks, in group A hyaline-like cartilage formation could be observed by histological examination; the newly formed cartilage, which stained for type II collagen, was detected by RT-PCR at high-level expression. Most of the GCBB was replaced by bone, while little remained in the underlying cartilage. At 36?weeks, GCBB was completely resorbed and a tidemark was observed in some areas. In contrast, groups B and C showed no cartilage formation but a great amount of fibrous tissue, with only a little bone formation. In summary, this study demonstrated that a novel scaffold, comprising a top layer of GCH, having mechanical properties comparable to native cartilage, and a bottom layer composed of GCBB, could be used to repair large osteochondral defects in joints. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22777833

Deng, Tianzheng; Lv, Jing; Pang, Jianliang; Liu, Bing; Ke, Jie

2012-07-01

213

Evolution equations for the joint probability of several compositions in turbulent combustion  

SciTech Connect

One-point statistical simulations of turbulent combustion require models to represent the molecular mixing of species mass fractions, which then determine the reaction rates. For multi-species mixing the Dirichlet distribution has been used to characterize the assumed joint probability density function (PDF) of several scalars, parametrized by solving modeled evolution equations for their means and the sum of their variances. The PDF is then used to represent the mixing state and to obtain the chemical reactions source terms in moment closures or large eddy simulation. We extend the Dirichlet PDF approach to transported PDF methods by developing its governing stochastic differential equation (SDE). The transport equation, as opposed to parametrizing the assumed PDF, enables (1) the direct numerical computation of the joint PDF (and therefore the mixing model to directly account for the flow dynamics (e.g. reaction) on the shape of the evolving PDF), and (2) the individual specification of the mixing timescales of each species. From the SDE, systems of equations are derived that govern the first two moments, based on which constraints are established that provide consistency conditions for material mixing. A SDE whose solution is the generalized Dirichlet PDF is also developed and some of its properties from the viewpoint of material mixing are investigated. The generalized Dirichlet distribution has the following advantages over the standard Dirichlet distribution due to its more general covariance structure: (1) its ability to represent differential diffusion (i.e. skewness) without affecting the scalar means, and (2) it can represent both negatively and positively correlated scalars. The resulting development is a useful representation of the joint PDF of inert or reactive scalars in turbulent flows: (1) In moment closures, the mixing physics can be consistently represented by one underlying modeling principle, the Dirichlet or the generalized Dirichlet PDF, and (2) based on the SDEs transported PDF mixing models for multi-species diffusion can be constructed by specifying the SDE coefficients.

Bakosi, Jozsef [Los Alamos National Laboratory

2010-01-01

214

High conductivity composite flip-chip joints and silver-indium bonding to bismuth telluride for high temperature applications  

NASA Astrophysics Data System (ADS)

Two projects are reported. First, the barrier layer and silver (Ag)-indium (In) transient liquid phase (TLP) bonding for thermoelectric (TE) modules at high temperature were studied, and followed with a survey of Ag microstructure and grain growth kinetics. Second, the high electrical conductivity joint materials bonded by both Ag-AgIn TLP and solid-state bonding processes for small size flip-chip applications were designed. In the first project, barrier and Ag-In TLP bonding layer for TE module at high temperature application were studied. Bismuth telluride (Bi2 Te3) and its alloys are used as materials for a TE module. A barrier/bonding composite was developed to satisfy the TE module for high temperature operation. Titanium (Ti)/ gold (Au) was chosen as the barrier layers and an Ag-rich Ag-In joint was chosen as the bonding layer. An electron-beam evaporated Ti layer was selected as the barrier layer. An Ag-In fluxless TLP bonding process was developed to bond the Bi 2Te3 chips to the alumina substrates for high temperature applications. To prepare for bonding, the Bi2Te3 chips were coated with a Ti/Au barrier layer followed by a Ag layer. The alumina substrates with titanium-tungsten (TiW)/Au were then electroplated with the Ag/In/Ag structure. These Bi2Te3 chips were bonded to alumina substrates at a bonding temperature of 180ºC with a static pressure as low as 100psi. The resulting void-free joint consists of five regions: Ag, (Ag), Ag2In, (Ag), and Ag, where (Ag) is Ag-rich solid solution with In atoms in it and Ag is pure Ag. This joint has a melting temperature higher than 660ºC, and it manages the coefficient of thermal expansion (CTE) mismatch between the Bi2Te3 and alumina substrate. The whole Ti/Au barrier layer and Ag-In bonding composite between Bi 2Te3 and alumina survived after an aging test at 250°C for 200 hours. The Ag-In joint transformed from Ag/(Ag)/Ag2In/(Ag)/Ag to a more reliable (Ag) rich layer after the aging test. Ag thin films were grown on various substrates and annealed at different conditions. The substrates include alumina metalized with TiW/Au, Bi 2Te3 metalized with palladium (Pd)/Au, silicon (Si) metalized with chromium (Cr)/Au, Si metalized with Pd/Au, 304 stainless steel metalized with nickel (Ni), and copper (Cu). The pre-exponential factor and activation energy of Ag grown on alumina/TiW/Au and Si/Cr/Au at 250-450°C were deduced from experimental results as 1.26cm2/s and 153kJ/mol, and as 0.07cm2/s and 140kJ/mol, respectively. In the second project, we studied the Ag-AgIn bonding and solid-state bonding. Several joint materials and bonding systems were studied with small dimenstion (10?m and 40mum) flip-chip designs, which include Ag joint with Ag-In transient liquid phase bonding, and Ag, Ag/Au and Cu/Au interconnections with solid-state bonding. The 40?m Ag-AgIn flip-chip interconnect process occurs at 180°C. An array of 50x50 Ag flip-chip joints with a 100?m pitch and 40?m joint diameter was created and bonded to the Cu substrate by depositing Ag/In/Ag at 180°C. The joint has a structure of Ag/(Ag)/Ag2In/(Ag) that connects the Si chip to the Cu substrate. The whole joint layer has a minimum melting temperature at 660°C. Cu/Au, Ag/Au, and Ag flip-chip interconnects were bonded to Cu substrate by solid-state bonding. The Cu substrate here was emulated as Cu electrodes on a package substrate. During the solid-state bonding process, heat and pressure were applied, and the bonding was done in a 100 torr vacuum. In the Cu/Au and Ag/Au flip-chip solid-state bonding experiments, an array of Cu/Au or Ag/Au interconnects with columns of 40mum x 40mum were created by photolithography and electroplating processes, and then bonded to the Cu substrate using a solid-state bonding process at 200°C with a static pressure of 250-400psi. The corresponding load for each column was set to as low as 0.22-0.35g. Cross section SEM images show that Cu/Au columns were all well bonded to the Cu substrate without any voids or cracks. The measured fracture force of Cu/Au and Ag/Au flip-chips wer

Lin, Wen P.

215

The Effect of Composition on the Wetting Behavior and Joint Strength of the Ag-CuO Reactive Air Braze  

SciTech Connect

One of the challenges in manufacturing solid-state electrochemical devices is in joining the ceramic and metallic components such that the resulting joint is rugged, hermetic, and stable under continuous high temperature operation in an oxidizing atmosphere. A well proven method of joining dissimilar materials is by brazing. Unfortunately many of the commercially available ceramic-to-metal braze alloys exhibit oxidation behavior which is unacceptable for potential use in a high temperature electrochemical device. An alternative braze alloy composition designed for oxidation resistance has been developed to join ferritic stainless steel to a variety of electrochemically active ceramic membranes including YSZ, nickel oxide, and mixed conducting perovskite oxides. The results of this study to date will be discussed.

Weil, K. Scott; Coyle, Christopher A.; Kim, Jin Yong Y.; Hardy, John S.

2003-05-15

216

Structural health monitoring of composite T-joints for assessing the integrity of damage zones  

NASA Astrophysics Data System (ADS)

This paper uses one category of Structural Health Monitoring (SHM) which uses strain variation across a structure as the key to damage detection. The structure used in this study was made from Glass Fibre Reinforced Plastic (GFRP). This paper discusses a technique developed called "Global Neural network Architecture Incorporating Sequential Processing of Internal sub Networks (GNAISPIN)" to predict the presence of multiple damage zones, determine their positions and also predict the extent of damage. Finite Element (FE) models of T-joints, used in ship structures, were created using MSC Patran(R) . These FE models were created with delaminations embedded at various locations across the bond-line of the structure. The resulting strain variation across the surface of the structure was observed. The validity of the Finite Element model was then verified experimentally. GNAISPIN was then used in tandem with the Damage Relativity Analysis Technique to predict and estimate the presence of multiple delaminations.

Kesavan, A.; Deivasigamani, M.; John, S.; Herszberg, I.

2006-04-01

217

Stress Analysis of In-Plane, Shear-Loaded, Adhesively Bonded Composite Joints and Assemblies.  

National Technical Information Service (NTIS)

Recent small aircraft that have been certified in the United States, such as the Cirrus SR20 and the Lancair Columbia 300, share similar structural attributes. Specifically, they are both of nearly all-composite construction and both make extensive use of...

H. Kim K. Kedward

2001-01-01

218

Optimal design of the press fit joint for a hybrid aluminum\\/composite drive shaft  

Microsoft Academic Search

In this work, a one-piece hybrid drive shaft composed of aluminum and carbon\\/epoxy composite was designed for a rear wheel drive automobile. The aluminum yoke was joined to the hybrid shaft by the press fit joining method using a steel ring which has many small teeth to increase reliability and to reduce manufacturing cost. To obtain high strength of the

Hak Sung Kim; Dai Gil Lee

2005-01-01

219

Effect of radial clearance between bolt and washer on the bearing strength of composite bolted joints  

SciTech Connect

When composite materials are bolted together, the relative diameters of the bolt hole, the constraining washer and the bolt itself have a profound effect on the ultimate bearing strength. Previous studies have investigated the effects of clearance between the bolt and the hole diameter. In this study, the effect of the difference between the bolt diameter and the inside diameter of the washer, which provides the lateral constraint at the edge of the hole, is examined. To explain the significant variation of bearing strength with bolt-to-washer clearance, a model is proposed to explain the mechanics of load transfer and the lateral deformation at the edge of the hole. The test results, using a quasi-isotropic graphite epoxy laminate, support the proposed model and provide data for designers. 16 refs.

Herrington, P.D.; Sabbaghian, M. (Louisiana State University, Baton Rouge (United States))

1992-01-01

220

A Simulated Annealing Procedure for the Joint Inversion of Spectroscopic and Compositional Data.  

NASA Astrophysics Data System (ADS)

A simulated annealing algorithm capable of inverting thermal emission spectra and compositional data acquired from a common geologic target has been developed. The inversion allows for the identification and proportion estimation of low concentration mineral endmembers. This method will be especially applicable to the 2007 Mars Mobile Geobiology Explorer equipped with an emission spectrometer for mineralogical analyses and a Laser Induced Breakdown Spectrometer for the remote acquisition of elemental information. The coupled inversion is cast as a multidimensional minimization problem where the hyperspace volume to be investigated is defined by the library endmembers at the disposal of the algorithm. This is a vector space in which exists all possible combinations of the library endmembers, with the endmember suite serving as an orthogonal set of basis vectors that span the hyperspace. The goal of the minimization is to locate the hyperspace coordinate that has the lowest associated model error value. This will correspond to the best possible model composition and mineralogy that can be generated by linearly mixing members of the endmember mineral suite. As opposed to standard unmixing routines, the simulated annealing algorithm is flexible enough to minimize any type of model error function. This allows the algorithm to interpret elemental analyses at any level of rigor, including elemental presence, relative abundances, abundance ratios, or exact mole percent. A synthetic data set was developed and systematically degraded with noise of various form and magnitude prior to being inverted with the simulated annealing algorithm as well as two purely spectral unmixing procedures. The simulated annealing procedure outperformed both of the alternate algorithms with an overall factor of two improvement in the mean sum of squares of deviations in the solution parameters. The detailed results from synthetic data inversions as well as the analysis of laboratory data will be presented.

Seelos, F. P.; Arvidson, R. E.

2001-12-01

221

Detection of fatigue cracks and torque loss in bolted joints  

NASA Astrophysics Data System (ADS)

Fatigue crack growth during the service life of aging aircraft is a critical issue and monitoring of such cracks in structural hotspots is the goal of this research. This paper presents a procedure for classification and detection of cracks generated in bolted joints which are used at numerous locations in aircraft structures. Single lap bolted joints were equipped with surface mounted piezoelectric (pzt) sensors and actuators and were subjected to cyclic loading. Crack length measurements and sensor data were collected at different number of cycles and with different torque levels. A classification algorithm based on Support Vector Machines (SVMs) was used to compare signals from a healthy and damaged joint to classify fatigue damage at the bolts. The algorithm was also used to classify the amount of torque in the bolt of interest and determine if the level of torque affected the quantification and localization of the crack emanating from the bolt hole. The results show that it is easier to detect the completely loose bolt but certain changes in torque, combined with damage, can produce some non-unique classifier solutions.

Coelho, Clyde K.; Das, Santanu; Chattopadhyay, Aditi; Papandreou-Suppappola, Antonia; Peralta, Pedro

2007-05-01

222

Failure Mechanisms of Thermomechanically Loaded SnAgCu\\/Plastic Core Solder Ball Composite Joints in Low-Temperature Co-Fired Ceramic\\/Printed Wiring Board Assemblies  

Microsoft Academic Search

The thermal fatigue endurance of completely lead-free 95.5Sn4Ag0.7Cu\\/plastic core solder ball (PCSB) composite joint structures\\u000a in low-temperature Co-fired ceramic\\/printed wiring board (LTCC\\/PWB) assemblies was investigated using thermal cycling tests\\u000a over the temperature ranges of ?40?C–125?C and 0?C–100?C. Two separate creep\\/fatigue failures initiated and propagated in\\u000a the joints during the tests: (1) a crack along the intermetallic compound (IMC)\\/solder interface on

O. Nousiainen; J. Putaala; T. Kangasvieri; R. Rautioaho; J. Vähäkangas

2007-01-01

223

Three-dimensional plate and contact/friction elements for laminated composite joints  

NASA Astrophysics Data System (ADS)

A contact/friction isoparametric finite element for the analysis of connections between laminated composite plates is presented. The element is compatible with a three-dimensional plate element based on layer-wise constant shear theory. The contact/friction element is based on a simple regularization of the unilateral contact with an orthotropic Coulomb friction problem. Two different friction coefficients in orthogonal directions and a constitutive law to model slip in any direction are used to account for the orthotropic surface texture of fiber-reinforced materials. The contact and friction constitutive law is distributed over the entire surface in contact/friction. The integration scheme is chosen to accurately account for the partial contact and slip inside the element, thus avoiding unnecessary mesh refinement. Unlike nodal gap elements, the proposed element applies the contact and friction constitutive laws uniformly over the contact/friction surface regardless of mesh refinement or element distortion. The irreversibility of the process leads to unsymmetric secant stiffness matrix. However, an iterative procedure working on symmetric matrices is proposed. Finally, numerical results are presented.

Barbero, E. J.; Luciano, R.; Sacco, E.

1995-02-01

224

Mechanical Characterization of Adhesive Bonded Sheet Metal Joints at Elevated Temperature  

NASA Astrophysics Data System (ADS)

A new approach is expected for heat resisting metal joints with inorganic adhesive. In the present study, the mechanical characterization of the inorganic adhesive and the strength evaluation of metal joints are realized by an experimental procedure that includes a static test for single lap joints bonded with inorganic adhesives. The inorganic adhesive can be cured at 150°C, and the maximum temperature resistance proposed is up to 1,200°C. A tensile shear test for the joints with a nickel adherend is performed at an elevated temperature of up to 400°C. The effect of material property, overlap length, and thickness of adherend on the joint strength is discussed based on stress analysis for corresponding joint models using a Finite Element Method. It is important to confirm whether fracture occurred in the adhesive layer or at the interface between the adhesive and the adherend. Therefore, the deformation and fracture behavior of the adhesive layer is investigated microscopically by the photographs of a scanning electron microscope (SEM) for the fracture surface.

Mori, Kiyomi; Azimin, Muhd; Tanaka, Masashi; Ikeda, Takashi

225

Effect of current crowding and Joule heating on electromigration-induced failure in flip chip composite solder joints tested at room temperature  

SciTech Connect

The electromigration of flip chip solder joints consisting of 97Pb-3Sn and 37Pb-63Sn composite solders was studied under high current densities at room temperature. The mean time to failure and failure modes were found to be strongly dependent on the change in current density. The composite solder joints did not fail after 1 month stressed at 4.07x10{sup 4} A/cm{sup 2}, but failed after just 10 h of current stressing at 4.58x10{sup 4} A/cm{sup 2}. At a slightly higher current stressing of 5.00x10{sup 4} A/cm{sup 2}, the composite solder joints failed after only 0.6 h due to melting. Precipitation and growth of Cu{sub 6}Sn{sub 5} at the cathode caused the Cu under bump metallurgy to be quickly consumed and resulted in void formation at the contact area. The void reduced the contact area and displaced the electrical path, affecting the current crowding and Joule heating inside the solder bump. Significant Joule heating inside solder bumps can cause melting of the solder and quick failure. The effect of void propagation on current crowding and Joule heating was confirmed by simulation.

Nah, J.W.; Suh, J.O.; Tu, K.N. [Department of Materials Science and Engineering, University of California at Los Angeles (UCLA), Los Angeles, California 90095-1595 (United States)

2005-07-01

226

A novel approach to predict the pin load distribution of multiple bolt-jointed composite laminate based on the circuit model  

NASA Astrophysics Data System (ADS)

The circuit model was applied to predict the pin load distribution of composite multiple bolt-joint structure. The load, flexibility and deformation of the mechanics model were equivalent to the current, resistance and voltage of the circuit model, respectively. Based on the above assumption, it could be found that the Hooke's law and the deformation compatibility equation in the origin mechanics model transformed into the Ohm's law and the voltage balance equation in the new circuit model. This approach translated the complex model of composite multiple bolt-jointed into a simple circuit model which consisted of some series circuits and parallel circuits. The analysis of the new circuit model had formed n-1 independence voltage balance equations and a current balance equation, thus, the current and load of each bolt could be calculated. In the new model, power sources which were added as required in some branch circuits could also simulate the clearance or interference in the origin model. Compared with the result of the multiple bolt-joints composite laminate test, the new approach could make an excellent performance to estimate the load distribution.

Yang, Xiankun; Chen, Haoyuan; Cheng, Linan; Zheng, Xitao

2011-11-01

227

Effect of welding speed on mechanical strength of friction welded joint of YSZ–alumina composite and 6061 aluminum alloy  

Microsoft Academic Search

Successful application of ceramics in many devices and structures requires some type of ceramic metal joining. All applications require a high-strength metal–ceramic bond. Even successful joint formation does not guarantee mechanical soundness of the joint. The inherent differences in physical properties between the ceramic and the metal make it extremely difficult to find an effective joining process that maintains the

M. B. Uday; M. N. Ahmad Fauzi; H. Zuhailawati; A. B. Ismail

2011-01-01

228

Interface microstructure and shear strength in the diffusion brazing joint of TiC–Al 2 O 3 ceramic composite with W18Cr4V tool steel  

Microsoft Academic Search

The diffusion brazing of TiC–Al2O3 ceramic composite with W18Cr4V tool steel is realized by using Ti and Cu filler metals at 1500°K for 1 h under a pressure\\u000a of 15 MPa in a vacuum of 10–5 Pa. Thus, a brazed TiC–Al2O3\\/W18Cr4V joint was obtained with an interface shear strength of up to 105 MPa. The microstructural characteristics of the\\u000a TiC–Al2O3\\/

Juan Wang; Yajian Li; Wanqun Huang

2009-01-01

229

Plug and play type joints in steel and steel–concrete composite constructions: Development guide and design considerations  

Microsoft Academic Search

Traditionally, for countries in Western Europe, joints in steel frame structures are realised using bolts and welds. In the workshop, the components are made using welding end plates and attachments and drilling of the bolt holes. On site, these structural components are connected together using bolts and nuts. The activities on site mean a large physical effort of the steel

Frans S. K. Bijlaard; Jan W. P. M. Brekelmans

2008-01-01

230

The Effect of Composition on the Wetting Behavior and Joint Strength of the Ag-CuO Reactive Air Braze  

Microsoft Academic Search

One of the challenges in manufacturing solid-state electrochemical devices is in joining the ceramic and metallic components such that the resulting joint is rugged, hermetic, and stable under continuous high temperature operation in an oxidizing atmosphere. A well proven method of joining dissimilar materials is by brazing. Unfortunately many of the commercially available ceramic-to-metal braze alloys exhibit oxidation behavior which

K. Scott Weil; Christopher A. Coyle; Jin Yong Y. Kim; John S. Hardy

2003-01-01

231

The effect of increasing carcass weight of finishing boars and gilts on joint composition and meat quality  

Microsoft Academic Search

Two hundred and eighty-eight crossbred (3\\/4 Landrace × 1\\/4 Large White) pigs, comprising equal numbers of boars and gilts, were housed in single sex groups from 50 kg liveweight to slaughter at liveweights of 92, 105, 118 and 131 kg (carcass weights of 70, 80, 90 and 100 kg). Sample joints from the left longissimus dorsi muscle were obtained at

V. E. Beattie; R. N. Weatherup; B. W. Moss; N. Walker

1999-01-01

232

Seismic retrofitting of damaged exterior beam–column joints using fibre reinforced plastic composite–steel plate combined technique  

Microsoft Academic Search

A conventional gravity load design philosophy for reinforced concrete (RC) structures has been slowly replaced by seismic design since the 1970s. But, till recently, capacity design and ductile detailing were not strictly implemented in practice in many developing countries which are prone to seismic hazard. In the present study, performance of exterior beam–column joints designed based on ductile and non-ductile

Saptarshi Sasmal; Balthasar Novák; K. Ramanjaneyulu; V. Srinivas; Constanze Roehm; N. Lakshmanan; Nagesh R. Iyer

2010-01-01

233

Effect of the combination of electromigration and thermomigration on phase migration and partial melting in flip chip composite SnPb solder joints  

NASA Astrophysics Data System (ADS)

Composite SnPb flip chip solder joints are used to study the combined effect of electromigration and thermomgration. The study showed that electromigration have led to the redistribution of Sn-rich phase and Pb-rich phase and displaced the low melting Sn-rich phase to the downward electron current crowding region in the contact area on the chip side. A pancake-type void forms and propagates at the contact interface and is accompanied by the migration of the Sn-rich phase followed by the partial melting of the solder joint. The migration of the Sn-rich phase was unexpected, and the location of the melting was unpredicted. We propose here that the migration of Sn-rich phase in the contact area is caused by thermomigration in the lateral direction owing to the existence of a localized hot spot at the current crowding region. The melting behavior is time dependent because it requires an incubation time for void formation, void propagation, and phase migration. Finally, the partial melting at the Sn-rich region occurs due to a large Joule heating at the end of the void growth before an electrical opening takes place.

Huang, Annie T.; Tu, K. N.; Lai, Yi-Shao

2006-08-01

234

Optical examination of load transfer in riveted lap joints using portable holographic interferometry  

NASA Astrophysics Data System (ADS)

In mechanically fastened single lap joints, such as those employed on aircraft fuselage skin splices, there are two distinct mechanisms of load transfer. At low values of load the transfer occurs primarily through friction between the component sheets while at higher loads the load is transferred by friction as well as through bearing at the fasteners. The load level at which the bearing mode of load transfer comes into action significantly affects the fatigue life of the joint, since the fasteners are stressed only at loads above this threshold load value. The portable holographic interferometry testing system (PHITS) is a robust, portable and sensitive non-destructive inspection system which produces contours of relative out of plane displacement by the method of superposition. PHITS is applied here to monitor the load transfer mechanism and identify the threshold at which the bearing mode comes into effect. In the friction mode there is no relative displacement between the fasteners and the skin panels. In the bearing mode the fasteners are loaded, causing a distinct tipping of the rivets, which is readily observable in the fringe pattern of deflection contours recorded by the holographic system.

Shankar, Krishnakumar; Baird, John P.; Clark, Robert K.; Williamson, Hugh M.

1997-03-01

235

Effect of pitch distance, row spacing, end distance and bolt diameter on multi-fastened composite joints  

Microsoft Academic Search

Two-dimensional finite element modelling has been used to determine the contact stress and load distribution in a multi-fastened composite laminate plate forming the inner lap of a double-lap joi configuration subjected to tensile loading. The effect of both elastic and rigid outer laps was investigated. The results obtained for the former showed good agreement with previously published work. For a

Surachate Chutima; Alvin P. Blackie

1996-01-01

236

Residual strains in an Al{sub 2}O{sub 3}-Ni joint bonded with a composite interlayer: Experimental measurements and FEM analyses  

SciTech Connect

A cylindrical Al{sub 2}O{sub 3}-Ni joint bonded with a 4.0 mm thick composite interlayer of 40 vol% Al{sub 2}O{sub 3}-60 vol% Ni was fabricated by powder processing, and the residual strains in the specimen were studied experimentally using neutron diffraction, X-ray diffraction, and optical fluorescence spectroscopy. Experimental measurements were compared with finite element modeling results obtained using a variety of different constitutive assumptions. The predicted residual strain distribution within the Al{sub 2}O{sub 3} along the center of the specimen was in reasonable agreement with neutron diffraction measurements, although the magnitude of the error in the experimental measurements did not allow a distinction to be made between the various modeling assumptions examined. In contrast, the predicted peak strains within the Al{sub 2}O{sub 3} along the specimen surface were significantly higher than those measured by X-ray diffraction or optical fluorescence spectroscopy, suggesting that strain relief occurred near the free edge during cooling. The mechanism of strain relief is believed to involve damage accumulation within the composite interlayer that was not accounted for in the constitutive models used.

Rabin, B.H.; Williamson, R.L.; Bruck, H.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Wang, X.L.; Watkins, T.R. [Oak Ridge National Lab., TN (United States); Feng, Y.Z.; Clarke, D.R. [Univ. of California, Santa Barbara, CA (United States)

1998-06-01

237

Inter- and intra-examiner reliability of single and composites of selected motion palpation and pain provocation tests for sacroiliac joint.  

PubMed

The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and provocation tests are used to examine the SIJ. It has been suggested that use of a cluster of motion palpation or provocation tests is a more acceptable method than single test to assess SIJ. This study examined the inter- and intra-examiner reliability of single and composites of the motion palpation and provocation tests together. Twenty-five patients between the ages of 20 and 65 years participated. Four motion palpation and three provocation tests were examined three times on both sides (left, right) by two examiners. Kappa coefficient and prevalence-adjusted and bias-adjusted kappa (PABAK) were calculated to evaluate the reliability. PABAK for intra- and inter-examiner reliability of individual tests ranged from 0.36 to 0.84 (95% CI: -0.22 to 1.12) and 0.52 to 0.84 (95% CI: -0.18 to 1.08) which is considered fair to substantial. PABAK for intra- and inter-examiner reliability for clusters of motion palpation or provocation tests ranged from 0.44 to 0.92 (95% CI: -0.36 to 1.2) which is considered moderate to excellent reliability. PABAK for intra- and inter-examiner reliability of composites of motion palpation and provocation tests ranged from 0.44 to 1.00 (95% CI: -0.22 to 1.12) and 0.52 to 0.92 (95% CI: -0.02 to 1.32) which is considered substantial to excellent. It seems that composites of motion palpation and provocation tests together have reliability sufficiently high for use in clinical assessment of the SIJ. PMID:18373938

Arab, Amir Massoud; Abdollahi, Iraj; Joghataei, Mohammad Taghi; Golafshani, Zahra; Kazemnejad, Anoshirvan

2008-03-25

238

Strength prediction of adhesive joints using the modified damage zone theory  

Microsoft Academic Search

The composite joint has become an important research area because the structural efficiency of a structure with a joint is determined by its joints rather than by its basic structure since the joints are often the weakest areas in composite structures. In this paper, the strengths of adhesive joints consisting of metal and composites were predicted and tested by the

Chang-Su Ban; Young-Hwan Lee; Jin-Ho Choi; Jin-Hwe Kweon

2008-01-01

239

Joint seismic, geodynamic and mineral physical constraints on three-dimensional mantle heterogeneity: Implications for the relative importance of thermal versus compositional heterogeneity  

NASA Astrophysics Data System (ADS)

The joint interpretation of seismic and geodynamic data requires mineral physical parameters linking seismic velocity to density perturbations in the Earth's mantle. The most common approach is to link velocity and density through relative scaling or conversion factors: R?/s = dln?/dlnVS. However, the range of possible R?/s values remains large even when only considering thermal effects. We directly test the validity of several proposed depth-dependent conversion profiles developed from mineral physics studies for thermally-varying properties of mantle materials. The tests are conducted by simultaneously inverting shear wave traveltime data and a diverse suite of convection-related constraints interpreted with viscous-flow response functions of the mantle. These geodynamic constraints are represented by surface spherical harmonic basis functions (up to harmonic degree 16) and they consist of the global free-air gravity field, tectonic plate divergences, dynamic surface topography and the excess ellipticity of the core-mantle boundary (CMB). The tests yield an optimum 1-D thermal R?/s profile that is generally compatible with all considered data, with the exception of the dynamic surface topography that is most sensitive to the shallow upper mantle. This result is not surprising given that cratonic roots are known to be compositionally-distinct from the surrounding ambient mantle. Moreover, it is expected that the temperature-dependence of the thermal R?/s in the upper mantle is significant due to the temperature-dependence of seismic attenuation or Q. Therefore, a simple 1-D density-velocity relationship is insufficient. To address this problem, we obtained independent estimates of the first-order correction factors to the selected R?/s profile within the cratonic roots and in the ambient (thermal) upper mantle. These correction factors, defined as ?R?/s/?lnVS, are highly negative within the cratons signifying considerable compositional buoyancy. This result confirms that the negative buoyancy associated with the low temperatures in the cratons is significantly counteracted by the composition-induced positive buoyancy resulting in near-neutral buoyancy of the cratonic roots. Within the ambient upper mantle, the correction factors are found to be positive which is consistent with the expected behaviour of the R?/s relationship in thermally-varying upper-mantle material. We obtain a significantly greater reconciliation of the global gravity anomalies and dynamic surface topography when applying these laterally-varying corrections compared to a simple 1-D R?/s relationship. Inversion for a fully 3-D R?/s relationship reveals secondary effects including additional compositional variation within the cratonic roots and the deep-mantle superplume structures. We estimate the relative magnitude of the thermal and compositional (non-thermal) contributions to mantle density anomalies and conclude that thermal effects dominate shear wave and density heterogeneity throughout the non-cratonic mantle. We also demonstrate the potential pitfalls of scaling a purely seismically-derived model to obtain density rather than performing a true joint inversion to obtain velocity and density simultaneously.

Simmons, Nathan A.; Forte, Alessandro M.; Grand, Stephen P.

2009-06-01

240

Evolving flexible joint morphologies  

Microsoft Academic Search

Transferring virtual robotic designs into physical robots has become possible with the development of 3D printers. Accurately simulating the performance of real robots in a virtual environment requires modeling a variety of conditions, including the physical composition of the robots themselves. In this paper, we investigate how modeling material flexibility through the use of a passive joint affects the resulting

Jared M. Moore; Philip K. McKinley

2012-01-01

241

Microstructure of Vacuum-Brazed Joints of Super-Ni/NiCr Laminated Composite Using Nickel-Based Amorphous Filler Metal  

NASA Astrophysics Data System (ADS)

Vacuum brazing of super-Ni/NiCr laminated composite and Cr18-Ni8 stainless steel was carried out using Ni-Cr-Si-B amorphous filler metal at 1060, 1080, and 1100 °C, respectively. Microstructure and phase constitution were investigated by means of optical and scanning electron microscopy, energy-dispersive spectroscopy, x-ray diffraction, and micro-hardness tester. When brazed at 1060-1080 °C, the brazed region can be divided into two distinct zones: isothermally solidified zone (ISZ) consisting of ?-Ni solid solution and athermally solidified zone (ASZ) consisting of Cr-rich borides. Micro-hardness of the Cr-rich borides formed in the ASZ was as high as 809 HV50 g. ASZ decreased with increase of the brazing temperature. Isothermal solidification occurred sufficiently at 1100 °C and an excellent joint composed of ?-Ni solid solution formed. The segregation of boron from ISZ to residual liquid phase is the reason of Cr-rich borides formed in ASZ. The formation of secondary precipitates in diffusion-affected zone is mainly controlled by diffusion of B.

Ma, Qunshuang; Li, Yajiang; Wu, Na; Wang, Juan

2013-06-01

242

Ceramic joints  

DOEpatents

Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

Miller, Bradley J. (Worcester, MA); Patten, Jr., Donald O. (Sterling, MA)

1991-01-01

243

Implication of unequal rivet load distribution in the failures and damage tolerant design of metal and composite civil aircraft riveted lap joints  

Microsoft Academic Search

Riveted lap joints are being used widely in civil aircraft structures. Conventional design procedures assume that the joint can be designed as if all rivets carry load equally. As found in literature associated with fatigue and fracture, forensic studies on structural failures, this assumption is not entirely valid. In this paper, the regulatory codes for civil aircraft as applicable to

S. Sathiya Naarayan; Satish Chandra

2009-01-01

244

The mechanics and tribology of fretting fatigue with application to riveted lap joints  

NASA Astrophysics Data System (ADS)

Fretting is the synergistic combination of wear, corrosion, and fatigue damage mechanisms driven by the partial slip of contacting surfaces. The surface microslip and near-surface contact stresses associated with fretting can lead to severe reduction in service lifetimes of contacting components as diversified as bearings, turbine blades and mechanically-fastened joints, both structural and biological. This tribologically induced degradation has come under close scrutiny by those responsible for maintaining aging fleets of both commercial and military aircraft. Thus a critical need exists for predicting fretting crack nucleation in riveted aluminum. aircraft joints. Fulfilling this need requires characterizing both the near-surface mechanics and intimately-related tribology of fretting. To this end, a well characterized experimental setup has been developed to generate carefully controlled and monitored fretting contacts to investigate the nature of the near-surface conditions. Included in this investigation were in-situ observations of the fretting contact stress field via a non-invasive thermal imaging technique and a characterization of the evolution of friction under partial slip conditions. With specific qualitative and quantitative understanding of these near-surface conditions, a series of fretting fatigue experiments have been conducted to validate a mechanics-based model for predicting fretting fatigue crack nucleation. Finally, efforts have been directed toward extending this understanding of fretting crack nucleation to riveted aircraft structure through modeling of the riveting process and a related experimental program designed to link riveting process parameters and fretting damage in single-lap joint structures. This work focuses specifically on determination of the residual stresses induced during rivet installation and the morphological characterization of fretting fatigue damage in the riveted test specimens manufactured under controlled conditions.

Szolwinski, Matthew Paul

245

Joint Replacement (Finger and Wrist Joints)  

MedlinePLUS

... mean to have a “joint replacement” or an “artificial joint”? The abnormal bone and lining structures of ... When should joint replacement surgery NOT be done? Artificial joints should not be done when: There is ...

246

Numerical analysis of adhesively bonded T-joints with structural sandwiches and study of design parameters  

Microsoft Academic Search

Adhesively bonded T-joints are extensively used in assembling sandwich structures. The advantage of adhesive bonded joints over bolted or riveted joints is that the use of fastener holes in mechanical joints inherently results in micro and local damages to the composite laminate during their fabrication. One type of adhesive joint in such structures is the T-joint between sandwich panels. The

S. M. R. Khalili; A. Ghaznavi

2011-01-01

247

Special two-dimensional and three-dimensional geometrically nonlinear finite elements for analysis of adhesively bonded joints  

NASA Astrophysics Data System (ADS)

Finite element models have been successfully used to analyze adhesive bonds in actual structures, but this takes a considerable amount of time and a high computational cost. The objective of this study is to develop a simple and cost-effective finite element model for adhesively bonded joints which could be used in industry. Stress and durability analyses of crack patch geometries are possible applications of this finite element model. For example, the lifetime of aging aircraft can be economically extended by the application of patches bonded over the flaws located in the wings or the fuselage. Special two- and three-dimensional adhesive elements have been developed for stress and displacement analyses in adhesively bonded joints. Both the 2-D and 3-D elements are used to model the whole adhesive system: adherends and adhesive layer. In the 2-D elements, adherends are represented by Bernoulli beam elements with axial deformation and the adhesive layer by plane stress or plane strain elements. The nodes of the plane stress-strain elements that lie in the adherend-adhesive interface are rigidly linked with the nodes of the beam elements. The 3-D elements consist of shell elements that represent the adherends and solid brick elements to model the adhesive. This technique results in smaller models with faster convergence than ordinary finite element models. The resulting mesh can represent arbitrary geometries of the adhesive layer and include cracks. Since large displacements are often observed in adhesively bonded joints, geometric nonlinearity is modeled. 2-D and 3-D stress analyses of single lap joints are presented. Important 3-D effects can be appreciated. Fracture mechanics parameters are computed for both cases. A stress analysis of a crack patch geometry is presented. A numerical simulation of the debonding of the patch is also included.

Andruet, Raul Horacio

248

Characterization and Prediction of Fracture within Solder Joints and Circuit Boards  

NASA Astrophysics Data System (ADS)

Double cantilever beam (DCB) specimens with distinct intermetallic microstructures and different geometries were fractured under different mode ratios of loading, psi, to obtain critical strain energy release rate, Jc. The strain energy release rate at crack initiation, Jci, increased with phase angle, psi, but remained unaffected by the joint geometry. However, the steady-state energy release rate, Jcs, increased with the solder layer thickness. Also, both the Jci and Jcs decreased with the thickness of the intermetallic compound layer. Next, mode I and mixed-mode fracture tests were performed on discrete (l=2 mm and l=5 mm) solder joints arranged in a linear array between two copper bars to evaluate the J = Jci (psi) failure criteria using finite element analysis. Failure loads of both the discrete joints and the joints in commercial electronic assemblies were predicted reasonably well using the J ci from the continuous DCBs. In addition, the mode-I fracture of the discrete joints was simulated with a cohesive zone model which predicted reasonably well not only the fracture loads but also the overall load-displacement behavior of the specimen. Additionally, the Jci calculated from FEA were verified estimated from measured crack opening displacements in both the continuous and discrete joints. Finally, the pad-crater fracture mode of solder joints was characterized in terms of the Jci measured at various mode ratios, psi. Specimens were prepared from lead-free chip scale package-PCB assemblies and fractured at low and high loading rates in various bending configurations to generate a range of mode ratios. The specimens tested at low loading rates all failed by pad cratering, while the ones tested at higher loading rates fractured in the brittle intermetallic layer of the solder. The J ci of pad cratering increased with the phase angle, psi, but was independent of surface finish and reflow profile. The generality of the J =Jci(psi) failure criterion to predict pad cratering fracture was then demonstrated by predicting the fracture loads of single lap-shear specimens made from the same assemblies.

Nadimpalli, Siva Prasad Varma

249

Investigation of the design and static behavior of cylindrical tubular composite adhesive joints utilizing the finite element method and stress-based failure theories  

NASA Astrophysics Data System (ADS)

The stress and strength behavior of cylindrical tubular adhesive joints composed of dissimilar materials was explored. This was accomplished with the finite element method (FEM) and stress-based failure theories. Also, it was shown how a design of experiments (DOE) based method can be used to objectively organize the process of optimizing joint strength by using stress-based failure criteria. The finite element program used in this work was written in-house from scratch to implement the FEM for the purpose of solving both axisymmetric and three-dimensional linear elastic governing equations of static equilibrium. The formulation of the three-dimensional model is presented, and the required operations to arrive to the axisymmetric model are also presented. The axisymmetric model is two dimensional, capable of using four and eight node quadrilateral elements. However, only four node elements are used because a mesh of eight node elements requires more memory and increased mesh refinement. The three-dimensional model is capable of using eight and twenty node brick elements, but only eight node brick elements are used for the same reason. Both of the axisymmetric and three-dimensional models calculate the nodal displacements, strains, stress values for each material, and strength values for each material. The external static loads can be individually applied, or coupled together. The outputs seem to be most useful for interpretation when plotted through-the-thickness (TTT) and along-the-length (ATL) of the joint or tube. Outputs are valid only for materials that behave linearly elastic up to (or near) failure, and the stress-based failure criteria are used to define that limit. A small laboratory-sized joint was modeled to look at the theoretical stress and strength distributions plotted along-the-length of the joint at different radial locations. These stress and strength distributions can be correlated to the type of load being applied because of unique or prominent features seen in the stress and strength distributions. The load can be a uniform temperature change, axial load, torque load, internal and external pressure, and/or bending load. A variance in the stress or strength for different joint sizes and materials is not examined closely due to the many possible combinations of these parameters.

Lambert, Michael D.

250

Deformation behavior of model MMC scarf joints  

Microsoft Academic Search

The mechanical response of metal interlayers constrained between two fiber-reinforced MMC (metal–matrix composites) sub-elements was investigated. The fibers were polycrystalline Al2O3, discontinuous at the joint, embedded in Al–4.5Mg, that was continuous through the joint and constituted both the composite matrix and the interlayer material. The specimens were produced by pressurized melt infiltration and comprised interlayers oriented from 0 to 75°

D. D Brink; J. C Mailand; C. G Levi; F. A Leckie

2000-01-01

251

Effect of nano-TiO2 addition on wettability and interfacial reactions of Sn0.7Cu composite solder\\/Cu solder joints  

Microsoft Academic Search

The influences of intermixing nano-TiO2 particles on the wettability and interfacial reaction of Sn0.7Cu composite solder with Cu substrate were investigated. The wettability of the Sn0.7Cu composite solder alloy was measured by the sessile-drop method under a 10-3 Torr vacuum solder at 250 °C up to 1800 s. Scanning electron microscopy (SEM) was used to quantify the interfacial microstructure for

L. C. Tsao; B. C. Wang; C. W. Chang; M. W. Wu

2010-01-01

252

Static strength of riveted joints in Fibre Metal Laminates  

Microsoft Academic Search

The ultimate strength of riveted joints utilizing fiber metal laminates (FML), a composite of aluminum alloy and glass or aramid prepreg layers, is investigated both analytically and experimentally. A structural analysis of the static strength of the joints, the failure modes including delamination, the effects of residual stress, and the application of a computer program to the design of joints

W. J. Slagter

1994-01-01

253

Joint strength predictions for adhesive joints to be used over a wide temperature range  

Microsoft Academic Search

The objective of this investigation was to design a joint, suitable for use from low to high-temperatures, by the combination of two adhesives, one for strength at high-temperatures and one for strength at low-temperatures. Such a joint is needed for the fuselage of supersonic aircraft, where aluminium or titanium \\/composite joints are common and kinetic heating at high speeds can

Lucas F. M. da Silva; R. D. Adams

2007-01-01

254

An Analytical Study on Debonding of Circular Single-Lap Patch Repairs Subjected to Axisymmetric Load  

NASA Astrophysics Data System (ADS)

Present paper is an analytical study on a patch repair problem. An exact solution based on a simplified plate model is obtained for single-patch-repaired circular plates with axisymmetric debondings between the patch and the base plate subjected to a uniform radial displacement, where significant bending deformation occurs owing to asymmetric configuration of the repaired plate. The debondings locate both at the outside edge of the patch and at the edge of the hole. The theoretical solution agreed well with a finite element solution. The basic mechanism of debonding problem of two dimensional patch repaired plate is discussed through the present theoretical solution and the finite element solutions. The nonlinear finite element results show that nonlinear effect is significant, while the nonlinear solution finally approaches the linear solution obtained by neglecting bending deformation. The linear solutions of energy release rate of the debonding crack with and without considering bending effect gives an upper and a lower limit. The linear exact solution neglecting bending deformation is applicable as a rough estimate at an early design stage since not only the solution gives upper limit but also the effect of the bending deformation on energy release rate of debonding crack decays quickly with the increase of the applied inplane displacement.

Suemasu, Hiroshi; Saito, Masayuki; Aoki, Yuichiro

255

Optimizations of wear resistance and toughness of hydroxyapatite nickel free stainless steel new bio-composites for using in total joint replacement  

Microsoft Academic Search

The aim of this work was to produce novel bio-composites made of hydroxyapatite and nickel free stainless steel (prepared by heat treating bone ash) and studying their mechanical properties including their tribology under various loads, toughness, and compressive and bending strengths. Different amounts of nickel free stainless steel powder (30, 40, 50 and 60wt.%) was added to this hydroxyapatite powder

M. Younesi; M. E. Bahrololoom

2010-01-01

256

Jointness: A Selected Bibliography.  

National Technical Information Service (NTIS)

JDEIS is the Joint Doctrine, Education and Training Community Electronic Information System. It encompasses a searchable Joint Doctrine Database, a Joint Education section that includes the JPME Prospective Research Topics Database, as well as award-winni...

L. Garder

2010-01-01

257

Characterization of adhesive bonded lap joints of C\\/C–SiC composite and Ti–6Al–4V alloy under varying conditions  

Microsoft Academic Search

The effect of glueline thickness, glueline length, etching time, temperature, exposure time and strain rate on C\\/C–SiC composite and Ti–6Al–4V alloy adherences were examined before and after adhesive bonding. The results show that the C\\/C–SiC adherence is more sensitive to strain rate and temperature than the Ti–6Al–4V adherence because of poor oxidizing resistance and high brittleness.

V. K Srivastava

2003-01-01

258

Strength Improvement of Adhesively-Bonded Joints Using a Reverse-Bent Geometry  

Microsoft Academic Search

Adhesive bonding of components has become more efficient in recent years due to the developments in adhesive technology, which has resulted in higher peel and shear strengths, and also in allowable ductility up to failure. As a result, fastening and riveting methods are being progressively replaced by adhesive bonding, allowing a big step towards stronger and lighter unions. However, single-lap

R. D. S. G. Campilho; A. M. G. Pinto; M. D. Banea; R. F. Silva; L. F. M. da Silva

2011-01-01

259

Tubular lap joints for wind turbine applications  

SciTech Connect

A combined analytical/experimental study of the strength of thick- walled, adhesively bonded PMMA-to-aluminum and E-glass/epoxy composite-to-aluminum tubular lap joints under axial load has been conducted. Test results include strength and failure mode data. Moreover, strain gages placed along the length of the outer tubular adherend characterize load transfer from one adherend to the other. The strain gage data indicate that load transfer is nonuniform and that the relatively compliant PMMA has the shorter load transfer length. Strains determined by a finite element analysis of the tested joints are in excellent agreement with those measured. Calculated bond stresses are highest in the region of observed failure, and extensive bond yielding is predicted in the E- glass/epoxy composite-to-aluminum joint prior to joint failure. 4 refs., 13 figs., 1 tab.

Reedy, E.D. Jr.; Guess, T.R.

1990-01-01

260

The use of nickel/aluminum explosively reactive nanolayers as localized heat sources in solder joints  

NASA Astrophysics Data System (ADS)

Although solder reflow continues to be the current state of the art in joining technology, conventional reflow makes use of furnace heating, in which all components must be exposed to temperatures higher than the melting temperature of the solder. Damaging temperature sensitive components and thermal stresses involved in joining materials of different thermal expansion coefficients are critical drawbacks in using furnace heating. An alternative heat source is provided by Ni/Al reactive nanolayer foils, which is a material comprised of thousands of alternating, nanoscale layers of Al and Ni. A small pulse of energy in the form of an electric spark ignites the reaction by initiating interlayer atomic diffusion. The reaction between these layers is exothermic, releasing enough heat to allow the reaction to propagate through the remainder of the sample. Due to its shape and localized nature of heat released, solder can be melted without heating layers beyond the solder, such as temperature sensitive bond components. In this study, a process is developed to integrate Ni/Al reactive nanolayer foils into bond structures using materials in current technologies. Si/solder/Si and Cu/solder/Cu solder joints are fabricated by reactive nanolayer soldering and are used to study the microstructure and mechanical properties. The microstructural and chemical analysis are performed using scanning and transmission electron microscopy and as well as X-Ray diffraction and energy dispersive analysis, respectively. Single-lap shear testing, through-thickness tensile testing, in-situ nanocompression, and nanoindentation are used to characterize the mechanical strength. Ni/Al nanolayers become a single phase, nanocrystalline NiAl phase as a result of the explosive reaction. The wetting of Sn-based solders is good on this layer, as evidenced by the interlocking branched microstructure as well as the formation of Ni3Sn4 at the interface. A joint shear strength of approximately 30 MPa was yielded when the initial temperature was 70°C and the applied pressure was 15 MPa. In-situ nanocompression results show the direct observation of <110> slip and nanoindentation analysis showed that the NiAI layer has large compressive residual stress.

Tong, Michael Shou-Ming

261

Joint Injection/Aspiration  

MedlinePLUS

... osteoarthritis. What usually is injected into the joint space? Corticosteroids (such as methylprednisolone and triamcinolone formulated to ... for producing inflammation and pain within the joint space. Although corticosteroids may also be successfully used in ...

262

Arthritis: Metacarpophalangeal (MP) Joint  

MedlinePLUS

... activities. Arthritis is the wearing away of the cartilage at a joint. Cartilage is the coating layer of tissue on the ... that acts as a shock-absorber. Loss of cartilage can lead to joint destruction and a shift ...

263

Large displacement spherical joint  

DOEpatents

A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)

2002-01-01

264

Collapsible mechanical joint  

NASA Astrophysics Data System (ADS)

A mechanical joint that can be configured to be either flexible or rigid is presented. The mechanical joint comprises three members which are flexibly attached to each other with a cable. When the cable is tightened, the three members come together to form a rigid joint capable of withstanding structural loads.

Robertson, Glen A.

1993-11-01

265

Bolted Hybrid Joints.  

National Technical Information Service (NTIS)

The report presents the results of an analytical study of hybrid steel butt joints of A36, A440 and A514 steel. The joints were fastened by either A325 or A490 bolts. The studies were designed to determine the effect of various variables on the joint stre...

R. Kormanik J. W. Fisher

1966-01-01

266

The effect of controlled shot peening on fusion welded joints  

Microsoft Academic Search

This work examines the effect of controlled shot peening (CSP) treatment on the fatigue strength of an ASTM A516 grade 70 carbon steel welded joint. Metallurgical modifications, hardness, elemental compositions, and internal discontinuities, such as porosity, inclusions, lack of penetration, and undercut found in treated and untreated fusion welded joints, were characterized. The fatigue results of as-welded and peened skimmed

Nur Azida Che Lah; Aidy Ali; Napsiah Ismail; Lim Poon Chai; Abdul Aziz Mohamed

2010-01-01

267

Multiaxial fatigue life evaluation of tubular adhesively bonded joints  

Microsoft Academic Search

The only viable method for joining plastic tubes and composite shafts is by bonding them adhesively. These structures are often subjected to complex cyclic loadings. Failure of these tubular joints not only depends on the applied loads, but also depends on the tube geometry, material properties of adhesive and tubes, and defects in the joint.The shear stress distribution in the

H. Nayeb-Hashemi; J. N. Rossettos; A. P. Melo

1997-01-01

268

Fatigue fracture of fully saturated bonded joints  

Microsoft Academic Search

The objective of this study was to compare the fatigue crack growth characteristics of adhesively bonded joints at several temperatures in air and salt water. Motivated by current trends in automotive structures, the specimens consisted of urethane adhesive bonding composite adherends with swirled glass fibers in an isocyanurate matrix. A modified cracked lap shear configuration under four-point bending was used

Kenneth M. Liechti; G. Alexis Arzoumanidis; Soo-Jae Park

2002-01-01

269

Joining of composite materials  

SciTech Connect

This Conference Proceedings contains 9 papers, of which one is abstracted separately, describing the latest achievement in effective methods of joining of composite structures. Most composite systems do not deform plastically and thus cannot alleviate stress concentration. The papers cover the design, analysis, testing and inspection of joined interfaces. Data are given for both mechanically fastened and adhesively bonded joints.

Kedward, K.T.

1981-01-01

270

Adhesive joints at high and low temperatures using similar and dissimilar adherends and dual adhesives  

Microsoft Academic Search

Adhesive joints with dual adhesives to be used over a wide temperature range (?55 to 200°C) were studied theoretically in a previous paper. The joint strength predictions have shown that, for identical adherends, the mixed modulus technique is of little benefit. However, for metal\\/composite joints, there is a real improvement, especially if the difference of coefficients of thermal expansion is

Lucas F. M. da Silva; R. D. Adams

2007-01-01

271

Structure and composition of the crust and upper mantle of the Archean-Proterozoic boundary in the Fennoscandian shield obtained by joint inversion of receiver function and surface wave phase velocity of recording of the SVEKALAPKO array  

NASA Astrophysics Data System (ADS)

We present a 3-D model of absolute values of S-wave velocities and VP/VS ratios in the crust and upper mantle beneath the SVEKALAPKO temporary seismic array that covered the transition zone between Archean and Proterozoic domains in the Precambrian Fennoscandian Shield. The model was obtained using joint inversion of P-wave receiver functions, Rayleigh phase velocities and traveltimes of waves converted from the 410 km discontinuity. P-wave receiver functions and traveltimes of Ps waves converted from the 410 km boundary were estimated for 30 broad-band stations of the SVEKALAPKO array and short-period, small-aperture RUKSA array in Russian Karelia. The phase velocities of Rayleigh waves were taken from previous surface wave studies (Bruneton et al. 2004a,b). For each station, the different data sets were merged and inverted by simulated annealing method. After that, a 3-D S-wave velocity model and distribution of VP/VS ratio was obtained from 1-D velocity models, using special interpolation technique. The new 3-D seismic model demonstrates pronounced lateral variations of values of VS and VP/VS ratio in the crust and uppermost mantle. The depth to the Moho boundary varies from 51 to 63 km in our model, which agrees with the results of previous controlled-source seismic studies in the region. The Moho boundary is overlain by a high-velocity lower crust (HVLC), with high VS, which is non-uniform in composition and origin. Our study showed no systematic correlation between the lithosphere structure and tectonothermal age of Archean and Proterozoic crustal terrains in the study area. The exposed Archean-Proterozoic suture (so-called Ladoga-Bothnian Bay Zone) is not observed as a mega-scale structure in the crust and upper mantle. Generally, the Archean-Proterozoic transition occupies a larger area in the lithosphere than it was thought earlier. It is marked by a Moho depression stretching to the North and by a zone of high VP and high VP/VS in the mantle. Our results supports the theory that the Fennoscandian Shield was assembled as a result of extensive collisional accretion of island arcs and microcontinental blocks and shows that these processes were working both in Archean and Proterozoic.

Kozlovskaya, Elena; Kosarev, Grigoriy; Aleshin, Igor; Riznichenko, Oksana; Sanina, Irina

2008-10-01

272

Design/analysis of the JWST ISIM bonded joints for survivability at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

A major design and analysis challenge for the JWST ISIM structure is thermal survivability of metal/composite adhesively bonded joints at the cryogenic temperature of 30K (-405°F). Current bonded joint concepts include internal invar plug fittings, external saddle titanium/invar fittings and composite gusset/clip joints all bonded to hybrid composite tubes (75mm square) made with M55J/954-6 and T300/954-6 prepregs. Analytical experience and design work done on metal/composite bonded joints at temperatures below that of liquid nitrogen are limited and important analysis tools, material properties, and failure criteria for composites at cryogenic temperatures are sparse in the literature. Increasing this challenge is the difficulty in testing for these required tools and properties at cryogenic temperatures. To gain confidence in analyzing and designing the ISIM joints, a comprehensive joint development test program has been planned and is currently running. The test program is designed to produce required analytical tools and develop a composite failure criterion for bonded joint strengths at cryogenic temperatures. Finite element analysis is used to design simple test coupons that simulate anticipated stress states in the flight joints; subsequently, the test results are used to correlate the analysis technique for the final design of the bonded joints. In this work, we present an overview of the analysis and test methodology, current results, and working joint designs based on developed techniques and properties.

Bartoszyk, Andrew; Johnston, John; Kaprielian, Charles; Kuhn, Jonathan; Kunt, Cengiz; Rodini, Benjamin; Young, Daniel

2005-08-01

273

Joint warfare system (JWARS)  

Microsoft Academic Search

The Joint Warfare System (JWARS) is a campaign-level model of military operations that is currently being developed under contract by the Office of the Secretary of Defense (OSD) for use by OSD, the Joint Staff, the Services, and the War fighting Commands. The behavior of military forces can be simulated from ports of embarkation through to their activities in combat.

A. Simlote

2003-01-01

274

Joint Seal Materials.  

National Technical Information Service (NTIS)

Three major experimental field installations of approximately 7 types of joint sealing materials were used to compare and evaluate the products of numerous sealant manufacturers. The sealants were placed in contraction joints (3/8 in. x 2 in.) which were ...

J. G. F. Hiss J. R. Lambert W. M. McCarty

1968-01-01

275

Joint remote state preparation  

Microsoft Academic Search

Alice, Bob and Charlie are three remote parties. Alice and Bob share the classical knowledge of a secret qubit state. We consider the following question: 'how can Alice and Bob jointly prepare the qubit state for Charlie?' Two different protocols are proposed for such a joint remote state preparation. The first protocol uses a single GHZ state while the second

Ba An Nguyen; Jaewan Kim

2008-01-01

276

Stress analysis of lap joints involving natural fibre reinforced interface layers  

Microsoft Academic Search

This paper is concerned with a fatigue study of composite adhesive lap joints. The tests were carried out on specimen joints manufactured using different stacking sequences: solely bi-directional woven E-glass fibres and polypropylene composites; and hybrid stacked composites. The main objective of the work was to improve the fatigue strength using hybrid fibre composites with a polypropylene\\/hemp natural fibre layer

J. M. Ferreira; H. Silva; J. D. Costa; M. Richardson

2005-01-01

277

Transforming Logistics: Joint Theater Logistics.  

National Technical Information Service (NTIS)

Effective and efficient management of joint theater logistics is a challenge for theater commanders. Current doctrine for joint theater logistics management provides broad non-directive guidance for developing a joint theater logistics system that can opt...

S. W. Pate

2006-01-01

278

Reliability and Failure Mechanism of Current-Stressed 99.3Sn0.7Cu\\/96.5Sn3Ag0.5Cu Composite Flip-Chip Solder Joints with Cu or Au\\/Ni\\/Cu Substrate Pad Metallization  

Microsoft Academic Search

Electromigration and thermomigration in the flip chip package are apparent in the reliability test. The 99.3Sn-0.7Cu\\/96.5Sn-3Ag-0.5Cu composite flip-chip solder joints with Ti\\/Ni(V)\\/Cu under bump metallurgy and different surface finishes are investigated when applied current density of 10 kA\\/cm2 and 15 kA\\/cm2 at 150degC and 125degC, respectively. Experimental results show the solder migrates to the Al trace in the chip when

Ying-Ta Chiu; Yu-Hsiu Shao; Yi-Shao Lai

2008-01-01

279

Adhesion study of thermoplastic polyimides with Ti-6Al-4V alloy and PEEK-graphite composites  

SciTech Connect

High glass transition (e.g. 360C) melt processable thermoplastic polyimide homopolymers and poly(imide-siloxane) segmented copolymers were prepared from a number of diamines and dianhydrides via solution imidization, polydimethylsilxane segment incorporation and molecular weight control with non-reactive phthalimide end-groups. The adhesive bond performance of these polyimides was investigated as a function of molecular weight, siloxane incorporation, residual solvent, test temperature, and polyimide structure via single-lap shear samples prepared from treated Ti-6Al-4V alloy adherends and compression-molded film adhesives of scrim-cloth adhesives. The adhesive bond strengths increased greatly with siloxane-segment incorporation at 10, 20 and 30 wt% and decreased slightly with total polymer molecular weight. As the test temperature was increased, adhesive bond strength increased, decreased or showed a maximum at some temperatures depending on the polyimide structure and siloxane content. The poly(imide-30% siloxane) segmented copolymer and a miscible poly(ether-imide) also demonstrated excellent adhesive bond strength with poly(arylene ether ketone) PEEK{reg sign}-graphite composites.

Yoon Taeho.

1991-01-01

280

ASCO/FDA JOINT  

Center for Drug Evaluation (CDER)

Text VersionPage 1. ASCO/FDA JOINT LUNG CANCER PANEL 2002-2003 Paul Bunn, MD (NCE-Chair) University of Colorado Cancer Center Denver, CO ... More results from www.fda.gov/downloads/drugs/developmentapprovalprocess

281

Joint Agency Turbulence Experiment.  

National Technical Information Service (NTIS)

Doppler radar data acquired during the 1981 Joint Agency Turbulence Experiment are presented. Pulse-pair processed reflectivity factor and Doppler spectrum mean data collected during volume scan periods are displayed over constant height surfaces at aircr...

A. R. Bohne

1983-01-01

282

Joint fluid Gram stain  

MedlinePLUS

... and shape of the cells help identify the bacteria. ... Abnormal results mean bacteria were seen on the Gram stain. This may be a sign of a joint infection, for example, gonococcal arthritis or arthritis due to Staphylococcus aureus.

283

Joint aspiration and injection.  

PubMed

Joint aspiration/injection is an invaluable procedure for the diagnosis and treatment of joint disease. The knee is the commonest site to require aspiration although any non-axial joint is accessible for obtaining synovial fluid. Septic arthritis and crystal arthritis can be readily diagnosed by aspirating synovial fluid. Intra-articular injection of long-acting insoluble corticosteroids produces rapid resolution of inflammation in most injected joints and is a well established procedure in rheumatological practice. The technique involves only a knowledge of basic anatomy and should not be unduly painful for the patient. Provided sterile equipment and a sensible, aseptic approach are used it is a safe procedure. This chapter addresses the indications, technical principals, expected benefits and risks of intra-articular corticosteroid injection. The use of other intra-articular injections including osmic acid, radioisotopes and hyaluronic acid, which are less universally utilised than intra-articular corticosteroid, will also be addressed. PMID:15939363

Courtney, Philip; Doherty, Michael

2005-06-01

284

Joint Healthcare Manpower Standards.  

National Technical Information Service (NTIS)

The purpose of the Standard is to ensure that the peacetime staffing requirements of the Military Health Services System (MHSS) provide quality medical care in a productive environment. The Joint Healthcare Manpower Standards (JHMS) provide the Department...

V. Melidosian

1989-01-01

285

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

An annual report of the JSEP (Joint Services Electronics Program) in solid state electronics, quantum electronics, information electronics, control and optimization, and electromagnetic phenomena is presented. Results of the research to date are summarize...

M. Tinkham

1991-01-01

286

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

An annual report of the JSEP (Joint Services Electronics Program) in solid state electronics, quantum electronics, information electronics, control and optimization, and electromagnetic phenomena is presented. Results of the research to date are summarize...

M. Tinkham

1987-01-01

287

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

This annual report of the JSEP (Joint Services Electronic Program) in solid state electronics, quantum electronics, information electronics, control and optimization, and electromagnetic phenomenon is presented. Results of the research to date are summari...

M. Tinkham

1985-01-01

288

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

An annual report of the JSEP (Joint Services Electronics Program) in Electromagnetics, Quantum Electronics, Solid State Electronics, Materials and Devices and Information System is presented. In addition, results of the research to date are summarized and...

W. G. Oldham

1986-01-01

289

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

An annual report of the JSEP (Joint Services Electronic Program) in solid state electronics, quantum electronics, information electronics control and optimization and electromagnetic phenomenon is presented. Results of the research to date are summarized ...

M. Tinkham

1985-01-01

290

Joint Services Electronics Program.  

National Technical Information Service (NTIS)

An annual report of the JSEP (Joint Services Electronics Program) in solid state electronics, quantum electronics, information electronics, control and optimization, and electromagnetic phenomena is presented. Results of the research to date are summarize...

M. Tinkham

1986-01-01

291

Prosthetic Joint Infections  

PubMed Central

Prosthetic joint infections represent a major therapeutic challenge for both healthcare providers and patients. This paper reviews the predisposing factors, pathogenesis, microbiology, diagnosis, treatment and prophylaxis of prosthetic joint infection. The most optimal management strategy should be identified based on a number of considerations including type and duration of infection, antimicrobial susceptibility of the infecting pathogen, condition of infected tissues and bone stock, patient wishes and functional status.

Aslam, Saima; Darouiche, Rabih O.

2012-01-01

292

Joint remote state preparation  

NASA Astrophysics Data System (ADS)

Alice, Bob and Charlie are three remote parties. Alice and Bob share the classical knowledge of a secret qubit state. We consider the following question: 'how can Alice and Bob jointly prepare the qubit state for Charlie?' Two different protocols are proposed for such a joint remote state preparation. The first protocol uses a single GHZ state while the second one uses a pair of EPR states as the quantum channel whose entanglement is not necessarily maximal.

Nguyen, Ba An; Kim, Jaewan

2008-05-01

293

High pressure ceramic joint  

DOEpatents

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Ward, Michael E. (Poway, CA); Harkins, Bruce D. (San Diego, CA)

1993-01-01

294

A safe joint with a joint torque sensor  

Microsoft Academic Search

In this study, a safe joint with a joint torque sensor is presented. The safe joint, named “Spring-Clutch”, is a simple passive mechanism that consists of a spring, a cam, and a joint torque sensor. When the torque applied is less than a pre-set threshold, the Spring-Clutch acts as a rigid joint between the input and output. However, if the

Dong-Eun Choi; Gi-Hun Yang; Junho Choi; Woosub Lee; Changhyun Cho; Sungchul Kang

2011-01-01

295

New plastic joints for plastic orthoses  

Microsoft Academic Search

Plastic joints for orthoses have more advantages than metal joints. They are lightweight, noiseless comfortable to use, rust proof, corrosion free, and radiolucent. Two types of plastic joints were developed by the authors, one for the ankle joint and the other for the knee joint, elbow joint or hip joint. Polypropylene was chosen as the joint material because of its

H. WATANABE; T. KUTSUNA; H. MORINAGA; T. OKABE

296

INDICATIONS FOR SACROILIAC JOINT FUSION  

Microsoft Academic Search

Sacroiliac joint fusion remains a useful piece of the surgical armamentarium. Newer percutaneous techniques for fusion supplement the older established procedures. The sacroiliac joint functions in the transmission of forces from the spine to the lower extremities and vice versa. It is a diarthrodial synovial joint that connects the sacrum to the ilium. The sacroiliac joint is unusual in that

Christopher A. Iobst; John A. Glaser

297

Joint impingement syndrome: clinical features  

Microsoft Academic Search

Joint impingement is a painful syndrome caused by the friction of joint tissues, which is both the cause and the effect of altered joint biomechanics. From the anatomical and clinical viewpoints, these syndromes are classified as bone impingement, soft tissue impingement and entrapment neuropathy, depending on what joint portion impinges on the others. We considered the most important impingement syndromes

Andrea Billi; Alessia Catalucci; Antonio Barile; Carlo Masciocchi

1998-01-01

298

Distal radioulnar joint injuries.  

PubMed

Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

Thomas, Binu P; Sreekanth, Raveendran

2012-09-01

299

Distal radioulnar joint injuries  

PubMed Central

Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis.

Thomas, Binu P; Sreekanth, Raveendran

2012-01-01

300

Periprosthetic Joint Infections  

PubMed Central

Implantation of joint prostheses is becoming increasingly common, especially for the hip and knee. Infection is considered to be the most devastating of prosthesis-related complications, leading to prolonged hospitalization, repeated surgical intervention, and even definitive loss of the implant. The main risk factors to periprosthetic joint infections (PJIs) are advanced age, malnutrition, obesity, diabetes mellitus, HIV infection at an advanced stage, presence of distant infectious foci, and antecedents of arthroscopy or infection in previous arthroplasty. Joint prostheses can become infected through three different routes: direct implantation, hematogenic infection, and reactivation of latent infection. Gram-positive bacteria predominate in cases of PJI, mainly Staphylococcus aureus and Staphylococcus epidermidis. PJIs present characteristic signs that can be divided into acute and chronic manifestations. The main imaging method used in diagnosing joint prosthesis infections is X-ray. Computed tomography (CT) scan may assist in distinguishing between septic and aseptic loosening. Three-phase bone scintigraphy using technetium has high sensitivity, but low specificity. Positron emission tomography using fluorodeoxyglucose (FDG-PET) presents very divergent results in the literature. Definitive diagnosis of infection should be made by isolating the microorganism through cultures on material obtained from joint fluid puncturing, surgical wound secretions, surgical debridement procedures, or sonication fluid. Success in treating PJI depends on extensive surgical debridement and adequate and effective antibiotic therapy. Treatment in two stages using a spacer is recommended for most chronic infections in arthroplasty cases. Treatment in a single procedure is appropriate in carefully selected cases.

Lima, Ana Lucia L.; Oliveira, Priscila R.; Carvalho, Vladimir C.; Saconi, Eduardo S.; Cabrita, Henrique B.; Rodrigues, Marcelo B.

2013-01-01

301

The Composition of Coding Joints Formed in V(D)J Recombination Is Strongly Affected by the Nucleotide Sequence of the Coding Ends and Their Relationship to the Recombination Signal Sequences  

Microsoft Academic Search

V(D)J recombination proceeds in two stages. Precise cleavage at the border of the conserved recombination signal sequences (RSSs) and the coding ends results in flush double-stranded signal ends and coding ends terminating in hairpins. In the second stage, the signal and coding ends are processed into signal and coding joints. Coding ends containing certain nucleotide homopolymers affect the efficiency of

UTHAYASHANKER R. EZEKIEL; TIANHE SUN; GRAZYNA BOZEK; URSULA STORB

1997-01-01

302

[Knee joint cyst].  

PubMed

Ninety cases of knee joint cysts were treated surgically. This included 50 patients with rheumatoid arthritis, 22 patients with degenerative-deforming changes, ten children with true cysts, and eight ones with post-traumatic cysts. Double-contrast X-ray examination with Lipiodol Ultra-fluid and air is of the best diagnostic value. All cases of knee joint cysts were treated surgically with a careful plastic closure of cyst gate. For this purpose the authors used the arcus tendon of the semi-membranous muscle. In cases of rheumatoid arthritis and degenerative changes cyst removal was preceded by synovectomy of the knee joint. Early and remote were good, no recurrence was observed. PMID:1299044

Noczy?ski, L; Benarz, W; Wojczys, R

1992-11-01

303

Joint polar satellite system  

NASA Astrophysics Data System (ADS)

The Joint Polar Satellite System (JPSS) is a joint NOAA/NASA mission comprised of a series of polar orbiting weather and climate monitoring satellites which will fly in a sun-synchronous orbit, with a 1330 equatorial crossing time. JPSS resulted from the decision to reconstitute the National Polar-orbiting Operational Environmental Satellite System (NPOESS) into two separate programs, one to be run by the Department of Defense (DOD) and the other by NOAA. This decision was reached in early 2010, after numerous development issues caused a series of unacceptable delays in launching the NPOESS system.

Trenkle, Timothy; Driggers, Phillip

2011-10-01

304

New Joint Sealants. Criteria, Design and Materials.  

ERIC Educational Resources Information Center

|Contents include--(1) sealing concrete joints, (2) sealing glass and metal joints, (3) metal and glass joint sealants from a fabricator's viewpoint, (4) a theory of adhesion for joint sealants, (5) geometry of simple joint seals under strain, (6) joint sealant specifications from a manufacturer's viewpoint, (7) joint sealant requirements from an…

Building Research Inst., Inc., Washington, DC.

305

Joint Fires Training Guide for a Corps Joint Task Force.  

National Technical Information Service (NTIS)

A detailed analysis of responsibilities, inputs, processes, outputs, and interactions was conducted for the staff elements and cells involved in joint fires at the Corps Joint Task Force level. This research product documents that analysis. The purpose of...

J. F. Love

1998-01-01

306

Position domain joint tracking  

Microsoft Academic Search

It was shown that the Vector Delay Lock Loop (VDLL) enhances the robustness of a GNSS receiver by exploiting the spatial correlation of the received signals. But due to the periodicity of the carrier, the VDLL only operates on the codephase and the carrier-frequency. In contrast to the VDLL, the Joint Tracking receiver manages to sustain the carrier-phase lock even

Kaspar Giger; C. Gu?nther

2010-01-01

307

First metatarsophalangeal joint arthrodesis.  

PubMed

First MTP joint arthrodesis continues to be a time-honored, effective, and valuable procedure as a primary or secondary surgery for various pathologies afflicting the first ray segment. Though commonly thought of as a salvage procedure, it has proven beneficial in the management of primary hallux limitus and rigidus, geriatric hallux valgus deformity, severe arthritis of any etiology, and conditions in which joint instability or deformity are not readily correctable by more traditional approaches. Since its initial description in the 1800s, the procedure has continued to be popular among orthopedic and podiatric surgeons. Success of the procedure is highly dependent on the position of fusion. Though surgeons are often fascinated and at times obsessed with a particular fixation technique, it cannot be over-emphasized that this takes a back seat to the importance of achieving proper position to meet the needs of an individual patient. Unlike joint resection or implant arthroplasty procedures, which commonly leave the hallux lacking stability and propulsion, first MPJ fusion has been shown to be effective during weight bearing and propulsion. The success enjoyed by the senior author continues to reinforce that motion is not necessary at the first MTP joint for good, pain-free function. PMID:15012033

Yu, Gerard V; Gorby, Paul O

2004-01-01

308

Clad metal joint closure  

SciTech Connect

A plasma arc spray overlay of cladding metals is used over joints between clad metal pieces to provide a continuous cladding metal surface. The technique permits applying an overlay of a high melting point cladding metal to a cladding metal surface without excessive heating of the backing metal.

Siebert, O.W.

1985-04-09

309

Dolphin Skeleton (Gliding Joint)  

NSDL National Science Digital Library

The dolphin is built to be sleek. Its body is made of almost entirely backbone (a gliding joint) which makes it very flexible under water. The ribs protect the inner organs of the dolphin and the tail beats from side to side, thrusting the animal forward.

Ketan Patel (California State University, Fullerton;)

2007-07-14

310

Joint Criminal Enterprise  

Microsoft Academic Search

The Joint Criminal Enterprise (JCE) doctrine has made an impressive appearance on the stage of the International Criminal Tribunal for the former Yugoslavia. However, the initial enthusiasm has faded somewhat recently as doubts about the doctrine's broad applicability have started to dominate the discussion. In this article, the author argues that we should not deplore the partial demise of the

Harmen van der Wilt

2007-01-01

311

Imaging the temporomandibular joint  

SciTech Connect

This book encompasses all imaging modalities as they apply to the Temporomandibular Joint and its disorders. The volume employs correlative line drawings to elaborate on diagnostic images. It helps teach methods of TMJ imaging and describes findings identified by different imaging modalities to both radiologists and dental clinicians.

Katzberg, R.W.; Manzione, J.V.; Westesson, P.L.

1988-01-01

312

BETTER BRAZED JOINTS  

Microsoft Academic Search

Brazing is presented as a technique for making high quality joints for ; use in corrosive environments and at elevated temperatures. The characteristics ; of an ideal, as well as commercially available brazing alloys based on silver, ; nickel, palladium, and gold are discussed. The conditions and equipment required ; for this type of brazing are described, as are the

1963-01-01

313

Bladder Operated Robotic Joint.  

National Technical Information Service (NTIS)

This invention is a robotic joint which is operated by inflatable bladders and which can be used in applications where it is desired to move or hold an object. A support block supports an elongated plate to which is pivotally attached a finger. A tension ...

G. A. Robertson

1992-01-01

314

Increasing the Strength of Adhesively Bonded Joints by Tapering the Adherends  

SciTech Connect

Wind turbine blades are often fabricated with composite materials. These composite blades are frequently attached to a metallic structure with an adhesive bond. For the baseline composite-to-steel joint considered in this study, failure typically occurs when the adhesive debonds from the steel adherend. Previous efforts established that the adhesive peel stresses strongly influence the strength of these joints for both single-cycle and fatigue loading. This study focused on reducing the adhesive peel stresses present in these joints by tapering the steel adherends. Several different tapers were evaluated using finite element analysis before arriving at a final design. To confirm that the selected taper was an improvement to the existing design, the baseline joint and the modified joint were tested in both compression and tension. In these axial tests, the compressive strengths of the joints with tapered adherends were greater than those of the baseline joints for both single-cycle and low-cycle fatigue. In addition, only a minor reduction in tensile strength was observed for the joints with tapered adherends when compared to the baseline joints. Thus, the modification would be expected to enhance the overall performance of this joint.

GUESS,TOMMY R.; METZINGER,KURT E.

1999-09-09

315

Joint Laser Designation Procedures (JLASER).  

National Technical Information Service (NTIS)

This publication provides joint procedures for employing laser designators with target acquisition systems and laser-guided weapons to enhance the combat effectiveness of joint US forces. Application Procedures established in this publication apply to the...

1991-01-01

316

A Systems Biology Approach to Synovial Joint Lubrication in Health, Injury, and Disease  

PubMed Central

The synovial joint contains synovial fluid (SF) within a cavity bounded by articular cartilage and synovium. SF is a viscous fluid that has lubrication, metabolic, and regulatory functions within synovial joints. SF contains lubricant molecules, including proteoglycan-4 and hyaluronan. SF is an ultrafiltrate of plasma with secreted contributions from cell populations lining and within the synovial joint space, including chondrocytes and synoviocytes. Maintenance of normal SF lubricant composition and function are important for joint homeostasis. In osteoarthritis, rheumatoid arthritis, and joint injury, changes in lubricant composition and function accompany alterations in the cytokine and growth factor environment and increased fluid and molecular transport through joint tissues. Thus, understanding the synovial joint lubrication system requires a multi-faceted study of the various parts of the synovial joint and their interactions. Systems biology approaches at multiple scales are being used to describe the molecular, cellular, and tissue components and their interactions that comprise the functioning synovial joint. Analyses of the transcriptome and proteome of SF, cartilage, and synovium suggest that particular molecules and pathways play important roles in joint homeostasis and disease. Such information may be integrated with physicochemical tissue descriptions to construct integrative models of the synovial joint that ultimately may explain maintenance of health, recovery from injury, or development and progression of arthritis.

Hui, Alexander Y.; McCarty, William J.; Masuda, Koichi; Firestein, Gary S.; Sah, Robert L.

2013-01-01

317

Sacroiliac joint abnormalities in paraplegics  

Microsoft Academic Search

We studied 186 paraplegic patients to clarify the pathogenesis of the sacroiliac (SI) joint abnormalities reported in these patients. Partial or complete fusion of SI joints was noted in 47 patients (25%), and milder degrees of abnormalities of these joints were present in 27 patients (15%). The abnormalities differed from those seen in ankylosing spondylitis and were found more commonly

M A Khan; I Kushner; A A Freehafer

1979-01-01

318

Joint Experimentation: A Systems Approach.  

National Technical Information Service (NTIS)

The Secretary of Defense charged the United States Atlantic Command (USACOM) on I October 1998 to conduct Joint Experimentation (JE) in support of the Defense of Department (DoD) Joint Vision 2010 concept. Since a common definition of joint experimentatio...

K. T. Royar

2000-01-01

319

Double slotted socket spherical joint  

DOEpatents

A new class of spherical joints is disclosed. These spherical joints are capable of extremely large angular displacements (full cone angles in excess of 270.degree.), while exhibiting no singularities or dead spots in their range of motion. These joints can improve or simplify a wide range of mechanical devices.

Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)

2001-05-22

320

The Challenges of Joint Attention  

Microsoft Academic Search

This paper discusses the concept of joint at- tention and the dierent skills underlying its development. We argue that joint attention is much more than gaze following or simul- taneous looking because it implies a shared intentional relation to the world. The current state-of-the-art in robotic and computational models of the dierent prerequisites of joint attention is discussed in relation

Frederic Kaplan; Verena V. Hafner

2004-01-01

321

Optimization and implementation of the smart joint actuator  

NASA Astrophysics Data System (ADS)

A new actuator system is being developed at the Cornell Laboratory of Intelligent Material Systems to address the problems of dynamic self-actuated shape change. This low profile actuator, known as the 'smart joint', is capable of maintaining rigidity in its nominal configuration, but can be actively strained to induce rotation at flexure joints. The joint is energetically efficient, only requiring power consumption during active morphing maneuvers used to move between shapes. The composite beam mechanism uses shape memory alloy (SMA) for strain actuation, with shape memory polymer (SMP) providing actively tailored rigidity due to its thermally varying properties. The first phase of the actuator development was modeling of the generic composite structure, proving analytically and computationally that the joint can produce useful work. The next phase focuses on optimization of this joint structure and usage, including ideal layering configurations and thicknesses in order to maximize various metrics specific to particular applications. Heuristic optimization using the simulated annealing algorithm is employed to best determine the structure of the joint at various scaling ratios, layering structures, and with varying external loading taken into account. The results are briefly compared to finite element models.

Manzo, Justin; Garcia, Ephrahim

2008-05-01

322

Metalceramic joint assembly  

Microsoft Academic Search

A metal-ceramic joint assembly in which a brazing alloy is situated between metallic and ceramic members. The metallic member is either an aluminum-containing stainless steel, a high chromium-content ferritic stainless steel or an iron nickel alloy with a corrosion protection coating. The brazing alloy, in turn, is either an Au-based or Ni-based alloy with a brazing temperature in the range

Jian

2002-01-01

323

Charcot joint of shoulder  

Microsoft Academic Search

Neuropathic arthropathy involving the shoulder is a relatively rare chronic disorder characterized by the destruction of the\\u000a joint which is also associated with decreased sensory innervation (Lequesne et al. in Rev Rhum Mal Osteoartic 49(6):427–437,\\u000a 1982; Yan?k et al. in Rheumatol Int 24(4):238–241, 2004). Here, we report a case of neuropathic arthropathy of the shoulder (charcot shoulder), secondary to syringomyelia

Korhan Ozkan; Umut Yavuz; Budak Akman; Namik Kemal Ozkan; Levent Eralp

2008-01-01

324

Joint Venture Marketing  

Microsoft Academic Search

Joint venture marketing links a for profit organization with a non-profit organization for their mutual benefit. Since American Express launched its 1981 Statue of Liberty\\/Ellis Island campaign, the strategy has proliferated among all types of health care organizations, manufacturers and even financial and educational institutions. With the successes have come concerns about non-profits having to compromise their integrity, the elimination

Nora Ganin Barnes

1991-01-01

325

Jointly Sponsored Research Program  

Microsoft Academic Search

U.S. Department of Energy (DOE) Cooperative Agreement DE-FC26-98FT40321 funded through the Office of Fossil Energy and administered at the National Energy Technology Laboratory (NETL) supported the performance of a Jointly Sponsored Research Program (JSRP) at the Energy & Environmental Research Center (EERC) with a minimum 50% nonfederal cost share to assist industry in commercializing and effectively applying highly efficient, nonpolluting

Everett A. Sondreal; John G. Hendrikson; Thomas A. Erickson

2009-01-01

326

38 CFR 4.45 - The joints.  

Code of Federal Regulations, 2010 CFR

...vertebrae, are considered groups of minor joints, ratable on a parity with major joints. The lumbosacral articulation and both sacroiliac joints are considered to be a group of minor joints, ratable on disturbance of lumbar spine...

2009-07-01

327

49 CFR 213.121 - Rail joints.  

Code of Federal Regulations, 2012 CFR

...Transportation 4 2012-10-01 2012-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

2012-10-01

328

49 CFR 213.121 - Rail joints.  

Code of Federal Regulations, 2011 CFR

...Transportation 4 2011-10-01 2011-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

2011-10-01

329

Metacarpophalangeal joint arthritis.  

PubMed

Arthritis of the metacarpophalangeal joint can result in considerable disability and pain. Inflammatory, posttraumatic, crystalline, and osteoarthritis are common etiologies of joint disease. A variety of nonsurgical treatment options have been shown to be effective, including activity modification, anti-inflammatory medications, splinting, and cortisone injections. In addition, newer generation disease-modifying antirheumatic drugs geared toward the treatment of rheumatoid arthritis have shown promise in retarding the inflammatory process. Another, relatively newer, conservative treatment option includes topical anti-inflammatories such as diclofenac sodium that are now approved by the Federal Drug Administration. Surgical treatment options most commonly include arthroplasty and arthrodesis. In the treatment of thumb metacarpophalangeal arthritis, arthrodesis is a popular and generally reliable surgical solution. In the fingers, arthroplasty remains the most common treatment option. Traditional constrained silicone joint replacements remain the most commonly used. Newer generation, unconstrained, surface replacement arthroplasties have shown promise in the treatment of osteoarthritis and select cases of inflammatory arthritis in which there is good bone stock, no or minimal deformity, adequate supporting soft tissues, and good disease control. PMID:21276901

Rizzo, Marco

2011-02-01

330

Dynamic glenohumeral joint stability.  

PubMed

Stability of the glenohumeral joint with an anterior, posterior, and inferior displacement force of 50 N was measured in a dynamic shoulder model. Controlled hydrodynamic actuator forces were applied to the deltoid muscle and to the rotator cuff in seven anatomic specimens. During elevation of the arm the position of the humerus was measured with a six-degree-of-freedom ultrasonic sensor device. The rotational center of the humeral head was used as a reference point for translation. A displacement force of 50 N led to significant humeral head displacement anteriorly and posteriorly but not inferiorly. A 50% reduction of rotator cuff forces increased anterior displacement by 46% and posterior displacement by 31%. Venting of the glenohumeral joint space and of the subacromial bursa resulted in a 50% increase of anterior displacement, a 19% increase of posterior displacement, and significant inferior displacement. This study demonstrates that in addition to passive stabilizers and negative intraarticular pressure, rotator cuff force significantly contributes to stabilization of the glenohumeral joint during arm motion. Muscle strength and coordination should gain more emphasis in the diagnosis and treatment of shoulder instability. PMID:9524340

Wuelker, N; Korell, M; Thren, K

331

Laboratory characterization of rock joints  

SciTech Connect

A laboratory characterization of the Apache Leap tuff joints under cyclic pseudostatic and dynamic loads has been undertaken to obtain a better understanding of dynamic joint shear behavior and to generate a complete data set that can be used for validation of existing rock-joint models. Study has indicated that available methods for determining joint roughness coefficient (JRC) significantly underestimate the roughness coefficient of the Apache Leap tuff joints, that will lead to an underestimation of the joint shear strength. The results of the direct shear tests have indicated that both under cyclic pseudostatic and dynamic loadings the joint resistance upon reverse shearing is smaller than that of forward shearing and the joint dilation resulting from forward shearing recovers during reverse shearing. Within the range of variation of shearing velocity used in these tests, the shearing velocity effect on rock-joint behavior seems to be minor, and no noticeable effect on the peak joint shear strength and the joint shear strength for the reverse shearing is observed.

Hsiung, S.M.; Kana, D.D.; Ahola, M.P.; Chowdhury, A.H.; Ghosh, A. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

1994-05-01

332

Joint slip in steel electric transmission towers  

Microsoft Academic Search

Joint slip is the relative displacement of a bolted joint under shear. It is greater in transmission towers as bolt diameters are small, members joined are thin, bearing type joints with a lower clamping force are used, and coefficient of friction of galvanized faying surfaces is low. This study on behaviour of such joints, incorporated 36 joint tests, generated joint

N Ungkurapinan; S. R. De S Chandrakeerthy; R. K. N. D Rajapakse; S. B Yue

2003-01-01

333

Fatigue crack growth acceleration due to intermittent overstressing in adhesively bonded CFRP joints  

Microsoft Academic Search

Double cantilever beam joints were used to investigate cohesive and interlaminar crack growth in bonded composite joints under constant and variable amplitude (VA) loading. Numerical crack growth integration was used to predict the VA fatigue life using constant amplitude data. This underestimated the fatigue crack growth rate for interlaminar cracks, indicating crack growth acceleration due to load interactions. This was

S Erpolat; I. A Ashcroft; A. D Crocombe; M. M Abdel-Wahab

2004-01-01

334

Effects of Carbon Nanotube Reinforcement on Adhesive Joints for Naval Applications.  

National Technical Information Service (NTIS)

The adhesive joint strength of various carbon fiber composite and steel joints was studied using Mode II fracture strength testing. The effect of the addition of multi-walled carbon nanotubes (MWNTs) to the adhesive was also studied. The effects of the MW...

G. L. Burkholder

2009-01-01

335

Novel joint deformation models and their application to delamination fracture analysis  

Microsoft Academic Search

Split beam type of fracture specimens is commonly used in the delamination evaluation of laminated composites. The compliance and energy release rate (ERR) of the specimens are examined in this study in the new light of the crack tip deformation. Three joint deformation models (i.e., the rigid, semi-rigid, and flexible joint models) describing the different degrees of crack tip deformation

Pizhong Qiao; Jialai Wang

2005-01-01

336

A tribological and biomimetic study of potential bone joint repair materials  

Microsoft Academic Search

This research investigates materials for bone-joint failure repair using tribological and biomimicking approaches. The materials investigated represent three different repairing strategies. Refractory metals with and without treatment are candidates for total joint replacements due to their mechanical strength, high corrosion resistance and biocompatibility. A composite of biodegradable polytrimethylene carbonate, hydroxyl apatite, and nanotubes was investigated for application as a tissue

Rahul Ribeiro

2006-01-01

337

Modified Soldered Joints of Current-Carrying Superconductors.  

National Technical Information Service (NTIS)

The improved soldered joints of composite superconductors are proposed. Their resistivity was measured under different variants of preparing at T=4.2 K and B less than or equal to 6 T. 4 refs.; 1 fig.; 1 tab. (Atomindex citation 19:070701)

I. N. Goncharov L. Miu

1987-01-01

338

2009 Wood and Fiber Product Seminar : VTT and USDA joint activity  

Treesearch

The programme focus is precisely on the development of sustainable ... and USDA in the field of wood- and fiber-based materials, and to evaluate possible joint ... Keywords: Biomaterial, wood, fiber, composites, packaging, passive building, ...

339

Joint hypermobility syndrome.  

PubMed

Although perceived as a rare condition, joint hypermobility syndrome is common. Its prevalence in rheumatology clinics is extremely high. Early estimates suggest that it may be the most common of all rheumatologic conditions. The problem lies in the general lack of awareness of the syndrome, its means of recognition, and the resultant failure to diagnose it correctly when present. It is a worldwide problem. This article provides an overview of hypermobility and hypermobility syndrome, stressing its multisystemic nature and the negative impact that it may have on quality of life, with particular reference to gastrointestinal involvement. PMID:23597972

Fikree, Asma; Aziz, Qasim; Grahame, Rodney

2013-05-01

340

On representations for joint moments using a joint coordinate system.  

PubMed

In studies of the biomechanics of joints, the representation of moments using the joint coordinate system has been discussed by several authors. The primary purpose of this technical brief is to emphasize that there are two distinct, albeit related, representations for moment vectors using the joint coordinate system. These distinct representations are illuminated by exploring connections between the Euler and dual Euler bases, the "nonorthogonal projections" presented in a recent paper by Desroches et al. (2010, "Expression of Joint Moment in the Joint Coordinate System," ASME J. Biomech. Eng., 132(11), p. 11450) and seminal works by Grood and Suntay (Grood and Suntay, 1983, "A Joint Coordinate System for the Clinical Description of Three-Dimensional Motions: Application to the Knee," ASME J. Biomech. Eng., 105(2), pp. 136-144) and Fujie et al. (1996, "Forces and Moment in Six-DOF at the Human Knee Joint: Mathematical Description for Control," Journal of Biomechanics, 29(12), pp. 1577-1585) on the knee joint. It is also shown how the representation using the dual Euler basis leads to straightforward definition of joint stiffnesses. PMID:24008987

O'Reilly, Oliver M; Sena, Mark P; Feeley, Brian T; Lotz, Jeffrey C

2013-11-01

341

Creep in shear of experimental solder joints  

SciTech Connect

Thermal fatigue failures of solder joints in electronic devices are a great concern in the electronics industry. Since the fatigue load is often in shear the details of thermal fatigue failure in shear are of particular interest. Recent work indicates that similar failure mechanisms operate in both thermal fatigue in shear and unidirectional creep in shear. Additionally, since the operative temperatures during thermal fatigue represent high solder homologous temperatures, creep deformation is certainly involved. These factors and the relative ease of conducting creep experiments encourage the study of solder joints under shear creep conditions. This work presents steady state shear creep rate vs shear stress data for several solder compositions, including the binary eutectic alloy and Pb-Sn alloyed with small amounts of Bi, Cd, In, and Sb, in a joint configuration. These data indicate that conventional creep mechanisms operate in the temperature and shear strain rate ranges studied. Extensive microstructural information is also reported. The microstructural evolution under creep conditions indicates that the instability of the as-cast binary Pb-Sn eutectic microstructure initiates creep failure. Changes of the as-solidified microstructure with the third element addition are reported as are the microstructural responses of each of these alloys to creep deformation. The efficacy of postponing the microstructural instability with the addition of small amounts of ternary elements is discussed. 27 refs., 13 figs., 1 tab.

Tribula, D.; Morris, J.W. Jr.

1989-09-01

342

Metal to ceramic sealed joint  

DOEpatents

A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.

Lasecki, J.V.; Novak, R.F.; McBride, J.R.

1991-08-27

343

Joining of polymer composite materials  

SciTech Connect

Under ideal conditions load bearing structures would be designed without joints, thus eliminating a source of added weight, complexity and weakness. In reality the need for accessibility, repair, and inspectability, added to the size limitations imposed by the manufacturing process and transportation/assembly requirements mean that some minimum number of joints will be required in most structures. The designer generally has two methods for joining fiber composite materials, adhesive bonding and mechanical fastening. As the use of thermoplastic materials increases, a third joining technique -- welding -- will become more common. It is the purpose of this document to provide a review of the available sources pertinent to the design of joints in fiber composites. The primary emphasis is given to adhesive bonding and mechanical fastening with information coming from documentary sources as old as 1961 and as recent as 1989. A third, shorter section on composite welding is included in order to provide a relatively comprehensive treatment of the subject.

Magness, F.H.

1990-11-01

344

Thermal Bonding of Thermoplastic Composites: Influence of Matrix and Interlayer on the Weld Fracture Toughness.  

National Technical Information Service (NTIS)

The various factors influencing the toughness of welded joints in thermoplastic composites are investigated. Three factors are identified as having a positive influence on weld quality. The use of an interlayer which creates fiber migration in the joint z...

B. Goffaux I. Verpoest

1990-01-01

345

A Biomimetic Structural Health Monitoring Approach Using Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

A self-sensing nanocomposite material has been developed to track the presence of damage in complex composite structures. Multiwalled carbon nanotubes are integrated with polymer matrix to develop a novel bonding material with sensing capabilities. The changes of the piezoresistance in the presence of damage are used to monitor the condition of bonded joints, where the usual bonding material is replaced by the self-sensing nanocomposite. The feasibility of this concept is investigated through experiments conducted on single-lap joints subject to monotonic tensile loading conditions. The results show that the self-sensing nanocomposite is sensitive to crack propagation within the matrix material. An acoustic emission-based sensing technique has been used to validate these results and shows good correlation with damage growth. A digital image correlation system is used to measure the shear strain field in the joint area.

Liu, Yingtao; Rajadas, Abhishek; Chattopadhyay, Aditi

2012-07-01

346

Influence of position and composition on adhesion to injection-molded TPO plaques as model automotive parts  

Microsoft Academic Search

Single lap shear adhesion measurements on model isotactic polypropylene and thermoplastic polyolefin (TPO) substrates which sandwich a chlorinated polyolefin (CPO) show similar values of the fracture strength, as determined from the stress at break, but much larger deformation at break for the substrates that contain a copolymer of ethylene with 9wt% butane (EBR9) as an impact modifier. We also found

Kangqing Deng; Neda Felorzabihi; Mitchell A. Winnik; Zhaohua Jiang; Zhihui Yin; Yuanqin Liu; Philip V. Yaneff; Rose A. Ryntz

2009-01-01

347

Development of a satellite structure with the sandwich T-joint  

Microsoft Academic Search

In this study, a monocoque satellite structure composed of many composite sandwich panels, which consist of two carbon fiber\\/epoxy composite faces and an aluminum honeycomb core, was designed to reduce structural mass and to improve static and dynamic structural rigidity. To join composite sandwich panels with T-shape joints, a new I-shape side insert, which was fixed inside the composite sandwich

Byoung Jung Kim; Dai Gil Lee

2010-01-01

348

CRUCIFORM CONTROL ROD JOINT  

DOEpatents

An invention is described which relates to nuclear reactor control rod components and more particularly to a joint between cruciform control rod members and cruciform control rod follower members. In one embodiment this invention provides interfitting crossed arms at adjacent ends of a control rod and its follower in abutting relation. This holds the members against relative opposite longitudinal movement while a compression member keys the arms against relative opposite rotation around a common axis. Means are also provided for centering the control rod and its follower on a common axis and for selectively releasing the control rod from its follower for the insertion of a replacement of the control rod and reuse of the follower. (AEC)

Thorp, A.G. II

1962-08-01

349

Smart material joint band  

NASA Astrophysics Data System (ADS)

The present invention relates to an improved connector for joining two tubular members together. The connector is formed by a plurality of longitudinally extending fingers extending from an end of one of the tubular members and at least one locking groove in the other of the tubular members for receiving the fingers. The connector further includes a circumferentially extending wire member which is received in a notch in a head portion of each of the plurality of fingers. The wire member is preferably formed from a shape memory alloy and has an original circumference less than the circumference of a circle formed by the notches in the head portions of the fingers. The connector includes apertures through which electric wires may be connected to the shape memory alloy ring member so as to cause the shape memory alloy ring member to return to its original shape and allow release of the joint connection.

Tucchio, Michael A.; Stoodt, Robert A.; Livsey, Robert A.

1993-12-01

350

Joint Targeting Planning Training Guide.  

National Technical Information Service (NTIS)

This guide resulted from an effort to develop a new approach to assessment and diagnostic training feedback in joint training. The guide resulted from a front-end analysis of joint targeting for an air campaign planning simulation. The analysis generated ...

J. F. Love

1998-01-01

351

Managing International Joint Venture Relationships  

Microsoft Academic Search

The purpose of the study is to describe and analyze the formation and development of international joint venture processes and relationships between the partners over time. Moreover, the study analyzes how far foreign partners have been successful in developing new contacts and in expanding their activities in local markets. We have carried out two case studies on joint ventures between

Akmal S. Hyder; Pervez N. Ghauri

2000-01-01

352

Articulated Joint for Deployable Structures.  

National Technical Information Service (NTIS)

A joint is described for connecting a pair of beams to pivot them between positions in alignment or beside one another, which is of light weight and which operates in a controlled manner. The joint includes a pair of fittings and at least one center link ...

N. D. Craighead R. J. Preliasco T. D. Hult

1983-01-01

353

International retail joint venture learning  

Microsoft Academic Search

Where retail entry mode decision-making is examined in the literature, it has almost exclusively focused upon international store acquisitions and franchising growth and expansion. In contrast, international joint venture decision-making processes are visibly absent in the international retail literature. This article explores three retail multinationals' international retail joint venturing experiences, extracting some of the salient lessons learned at each stage

Mark Palmer

2006-01-01

354

Industrial robots with seven joints  

Microsoft Academic Search

In a physical 3-dimensional free space at most six degrees of freedom can be independent, i.e. three for position and three for orientation. Intuitively robots with six joints are adequate to execute any tasks. However, in reality, constraints often exist under the complex environment so that six joints are not quite enough for the robots. An insertion of an additional

J. Y. S. Luh; Y. L. Gu

1985-01-01

355

Joint attention and language evolution  

Microsoft Academic Search

This study investigates how more advanced joint attentional mechanisms, rather than only shared attention between two agents and an object, can be implemented and how they influence the results of language games played by these agents. We present computer simulations with language games showing that adding constructs that mimic the three stages of joint attention identified in children's early development

Johan Kwisthout; Paul Vogt; Pim Haselager; Ton Dijkstra

2008-01-01

356

High pressure tubular swivel joint  

Microsoft Academic Search

A swivel joint and connection for abutting high pressure hydraulic manifolds are described. The joint consists of 2 flanged nonrotating swivel bodies, with one of the nonrotating swivel bodies having a rotating swivel body journaled in it. A flanged tubular sleeve is secured between the adjacent end faces of the 2 nonrotating swivel bodies. A static annular seal is disposed

Kendrick

1976-01-01

357

High pressure tubular swivel joint  

Microsoft Academic Search

A swivel joint and connection for abutting high pressure hydraulic manifolding are described. The joint consists of 2 flanged nonrotating swivel bodies, with one of the nonrotating swivel bodies having a rotating swivel body journaled in it. A flanged tubular sleeve is secured between the adjacent end faces of the 2 nonrotating swivel bodies, with the opposite ends of the

W. D. Kendrick; B. J. Frazier

1976-01-01

358

Composite drill pipe  

DOEpatents

A composite pipe segment is formed to include tapered in wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self centering receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces. The distal peripheries of the nested end pieces are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes a contact ring in one pipe assembly pierced by a pointed contact in the other to connect the corresponding leads across the joint.

Leslie, James C. (Fountain Valley, CA); Leslie, II, James C. (Mission Viejo, CA); Heard, James (Huntington Beach, CA); Truong, Liem (Anaheim, CA), Josephson; Marvin (Huntington Beach, CA), Neubert; Hans (Anaheim, CA)

2008-12-02

359

Joint Tactics, Techniques, and Procedures for Joint Logistics Over the Shore.  

National Technical Information Service (NTIS)

1. Purpose. This publication sets forth joint doctrine and joint tactics, techniques, and procedures for conducting Joint Logistics Over The Shore (JLOTS) operations by the US Military Services during the conduct of joint operations. It provides basic doc...

1991-01-01

360

How geometric details can affect the strength of adhesive lap joints  

SciTech Connect

The durability of adhesively bonded joints--when utilized as blade attachments--has a significant impact on the performance of wind turbines. Accordingly, there is interest in determining how geometric details affect the strength of these joints. Finite element analyses were performed to aid in the selection of three composite-to-metal joint geometries for compressive axial testing. Both monotonic and low-cycle fatigue tests were conducted. Analysis and testing of these joints provide insight into the effects of adding extra adhesive to the end of the bond or tapering the metal adherend. The issue of whether the relative performance of different joints in monotonic tests can be used to predict the relative fatigue strength of these joints is also addressed.

Metzinger, K.E.; Guess, T.R.

1996-12-31

361

Provocative sacroiliac joint maneuvers and sacroiliac joint block are unreliable for diagnosing sacroiliac joint pain  

Microsoft Academic Search

Mapping studies of pain elicited by injections into the sacroiliac joints (SIJs) suggest that sacroiliac joint syndrome (SIJS) may manifest as low back pain, sciatica, or trochanteric pain. Neither patient-reported symptoms nor provocative SIJ maneuvers are sensitive or specific for SIJS when SIJ block is used as the diagnostic gold standard. This has led to increasing diagnostic use of SIJ

Jean-Marie Berthelot; Jean-Jacques Labat; Benoît Le Goff; François Gouin; Yves Maugars

2006-01-01

362

Applications Of The Universal Joint Task List To Joint Exercise Results  

Microsoft Academic Search

The foundation of readiness is training. The Chairman, Joint Chiefs of Staff (CJCS) Joint Training Program institutes methods for identifying training requirements through review of the Commander-in-Chief's (CINC) missions and the compilation of Joint Mission Essential Task Lists. The Universal Joint Task List comprehensively outlines these joint essential tasks, providing a summary of CINC missions, joint tasks, and corresponding supporting

Sam H. Parry; Michael C. McAneny; Richard J. Dromerhauser

1997-01-01

363

Applications of the universal joint task list to joint exercise results  

Microsoft Academic Search

The foundation of readiness is training. The Chairman, Joint Chiefs of Staff (CJCS) Joint Training Program institutes methods for identifying training requirements through review of the Commander-in-Chief's (CINC) missions and the compilation of Joint Mission Essential Task Lists. The Universal Joint Task List comprehen- sively outlines these joint essential tasks, providing a summary of CINC missions, joint tasks, and corre-

Sam H. Parry; Michael C. McAneny; Richard J. Dromerhauser

1997-01-01

364

Regenerative Medicine and Restoration of Joint Function.  

National Technical Information Service (NTIS)

Currently amputation, arthrodesis (joint fusion), or joint replacement are used to treat a joint with an intra-articular fracture or destroyed by a combat injury. Generation of personalized, anatomically shaped biological implants formed using techniques ...

E. Toyserkani M. Hurtig P. Zalzal R. Kandel R. Pilliar

2012-01-01

365

Evaluation of Joint Sealants of Concrete Pavements.  

National Technical Information Service (NTIS)

This report document investigation of concrete pavement joint sealants which began with project 1371 'Evaluation of Joint Sealants.' The purpose of the continued investigation is to propose specification and test protocol for joint sealants in concrete pa...

A. H. Gurjar T. Tang D. G. Zollinger

1997-01-01

366

Standing Joint Force Headquarters: A Planning Multiplier.  

National Technical Information Service (NTIS)

The Standing Joint Force Headquarters (SJFHQ) provides a planning multiplier by bringing both joint and regional expertise to the Joint Task Force Headquarters (JTFHQ), thereby increasing its capabilities. These capabilities assist in the rapid establishm...

C. A. Barkley

2006-01-01

367

Free Vibration Characteristics of Hybrid SPR Beams  

NASA Astrophysics Data System (ADS)

This paper deals with torsional free vibration analysis of single lap-jointed encastre hybrid SPR beams. The finite element analyses are carried out using the commercially-available ANSYS FEA program. The focus of the analysis is to reveal the influence on the natural frequencies, natural frequency ratios and mode shapes of single lap-jointed encastre hybrid SPR beams caused by variations in the material properties of the adhesives. Numerical examples show that the torsional natural frequencies of single lap jointed encastre hybrid SPR beams increase significantly as the Young's modulus of the adhesive increase, but only slight change with an increase in Poisson's ratio. The mode shapes show that there are different deformations in the jointed section of the odd and even modes. These different deformations may result different dynamic response and different stress distributions.

He, Xiaocong; Dong, Biao; Zhu, Xunzhi

2010-05-01

368

Soldering of mild steels: functional joints  

SciTech Connect

In recent years, adhesive joints have replaced numerous soldered joints, especially in applications where electrical conductivity is not required from the members of the joint. Nevertheless, soldered joints are still used in applications ranging from electronics to high-technology components. The present work seeks to demonstrate that soldered joints, which can be considered as functional joints, have very good mechanical properties and can provide more than acceptable levels of leak tightness. Hence, microstructural characterisation studies have been carried out on the filler metals used to solder mild steel, the surface preparation required to achieve the best final properties has been assessed, the joints characterised by means of radiography and the mechanical properties of the joints determined. The results obtained for soldered joints have been compared with those obtained from adhesive and hybrid joints. Finally, scanning electron microscopy has been performed on the fracture surfaces of the soldered joint.

Molleda, F.; Mora, J.; Molleda, F.J.; Carillo, E.; Mellor, B.G

2003-12-15

369

Lumbar Zygapophysial (Facet) Joint Injections  

MedlinePLUS

... arthritis) in the facet joints may contribute to low back pain and may be visualized on diagnostic imaging. However, ... sometimes called “block”) may be performed. If the low back pain pain is reduced or relieved after an anesthetic ...

370

Joint Service Family Support Network.  

National Technical Information Service (NTIS)

The Joint Service Family Support Network is an Office of the Secretary of Defense pilot program in the Pacific Region, working in concert with civilian agencies, intended to establish a comprehensive multi-agency approach for community support and service...

J. Chambers

2007-01-01

371

Joint Infection (Beyond the Basics)  

MedlinePLUS

... The Basics) Patient information: Septic arthritis (The Basics) Pseudomonas aeruginosa skin, soft tissue, and bone infections Septic arthritis ... Clinical manifestations and diagnosis of prosthetic joint infections Pseudomonas aeruginosa skin, soft tissue, and bone infections Septic arthritis ...

372

Joint Measurement Operations Controller (JMOC).  

National Technical Information Service (NTIS)

The increasingly complex interactions of systems of systems for training today's military means that supporting joint training exercises includes supporting live, virtual and constructive simulations. Capturing and integrating observer-based measures with...

B. Schaab J. Ayers J. Feeney M. Puglisi W. Salter

2011-01-01

373

Global Optimization of Compositional Systems  

Microsoft Academic Search

Embedded systems typically consist of a composition of a set of hardware and software IP modules. Each module is heavily optimized by itself. However, when these modules are composed together, significant additional opportunities for optimizations are introduced because only a subset of the entire functionality is actually used. We propose COSE-a technique to jointly optimize such designs. We use symbolic

Fadi Zaraket; John Pape; Adnan Aziz; Magarida Jacome; Sarfraz Khurshid

2007-01-01

374

Global Optimization of Compositional Systems  

Microsoft Academic Search

Embedded systems typically consist of a composition of a set of hardware and software IP modules. Each module is heavily optimized by itself. However, when these modules are composed together, significant additional opportunities for optimizations are introduced because only a subset of the entire functionality is actually used. We propose COSE—a technique to jointly optimize such designs. We use symbolic

Fadi A. Zaraket; John Pape; Adnan Aziz; Magarida F. Jacome; Sarfraz Khurshid

2007-01-01

375

Joint probabilities and quantum cognition  

NASA Astrophysics Data System (ADS)

In this paper we discuss the existence of joint probability distributions for quantumlike response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

de Barros, J. Acacio

2012-12-01

376

Joint probabilities and quantum cognition  

SciTech Connect

In this paper we discuss the existence of joint probability distributions for quantumlike response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

Acacio de Barros, J. [Liberal Studies, 1600 Holloway Ave., San Francisco State University, San Francisco, CA 94132 (United States)

2012-12-18

377

Analysis of bolted and bonded composite  

Microsoft Academic Search

In the analysis and design of bonded and bolted composite joints, certain input data are required that are not readily available. Many engineering hours at the depots are expended in obtaining the required information. Even when the data are obtained, the accuracy of it is sometimes questionable. The availability of this information in a computerized database would greatly facilitate composite

Seng C. Tan

1992-01-01

378

ACLICO: Un Systeme d'Aide a la Conception des Liaisons Collees (ACLICO: An Aid System for Designing Bonded Joints).  

National Technical Information Service (NTIS)

Practical applications of artificial intelligence techniques in an industrial setting are outlined. ACLICO, an aid system for the design of bonded joints between materials, composite or otherwise, is described. The approach adopted, the architecture of th...

M. Laborie

1991-01-01

379

49 CFR 213.351 - Rail joints.  

Code of Federal Regulations, 2011 CFR

...Transportation 4 2011-10-01 2011-10-01 false Rail joints. 213.351 Section 213.351 Transportation...Operations at Track Classes 6 and Higher § 213.351 Rail joints. (a) Each rail joint, insulated joint, and compromise...

2011-10-01

380

49 CFR 213.351 - Rail joints.  

Code of Federal Regulations, 2012 CFR

...Transportation 4 2012-10-01 2012-10-01 false Rail joints. 213.351 Section 213.351 Transportation...Operations at Track Classes 6 and Higher § 213.351 Rail joints. (a) Each rail joint, insulated joint, and compromise...

2012-10-01

381

Synovial chondromatosis of the acromioclavicular joint  

Microsoft Academic Search

Synovial chondromatosis involving the acromioclavicular joint is very rare. We report a case of synovial chondromatosis of the acromioclavicular joint associated with synovial cyst formation. Arthrography of the acromioclavicular joint revealed that the loose bodies lay within a synovial cyst which was in communication with the acromioclavicular joint. Synovectomy including removal of the synovial cyst and the loose bodies relieved

J. Ozaki; Y. Tomita; Y. Nakagawa; O. Kisanuki; S. Tamai

1993-01-01

382

Degenerative joint disease in captive waterfowl  

Microsoft Academic Search

A retrospective study was conducted to evaluate degenerative joint disease (DJD) in captive waterfowl that died or were euthanized at Fresno's Chaffee Zoo in Fresno, California, USA from 2001 to 2005. Of these, 16 out of 33 birds (48%) had DJD in one or both stifle (femoral–tibiotarsal joint; n = 13), hock (tibiotarsal–tarsometatarsal joint; n = 4), or toe joints

L. A. Degernes; P. S. Lynch; H. L. Shivaprasad

2011-01-01

383

Interface failure in lead free solder joints  

Microsoft Academic Search

The phenomenon of interface failure in lead free solder joints was explored using solder joint array tensile testing. The effects of pad metallization, solder alloy, reflow conditions, and post reflow thermal aging were quantified. The joint strength ranged from 5 to 115MPa. The joint ductility dropped to zero in some cases. The interface microstructure and failure mode were characterized for

Robert Darveaux; Corey Reichman; Nokibul Islam

2006-01-01

384

Jointness and the Impact of the War.  

National Technical Information Service (NTIS)

Operations during World War II clearly and repeatedly demonstrated the advantages of jointness and the penalties for failing to achieve it. At war's end, the Joint Chiefs of Staff (JCS) supported jointness in principle, but the progress of jointness was s...

D. A. Armstrong

1995-01-01

385

Creep properties of Sn-Ag solder joints containing intermetallic particles  

NASA Astrophysics Data System (ADS)

The creep behavior of the eutectic tin-silver joints and tin-silver composite solder joints containing 20 vol.% of Cu6Sn5, Ni3Sn4, and FeSn2 intermetallic reinforcements introduced by in-situ methods was investigated. These creep tests were carried out using single shear lap solder joints at room temperature, 85°C, and 125°C. The creep resistance was similar in magnitude for all alloys, and with increasing temperature, the stressexponents decreased in a manner consistent with power-law breakdown behavior. The FeSn2 intermetallic reinforced composite solder was found to be the most creep-resistant alloy at room temperature. Creep failure was observed to occur within the solder matrix in all these solder joints. Although a detailed analysis of the processes involved was difficult because of smearing of the features in the fracture surface, there were indications of grain-boundary separation, ductile fracture, and interfacial separation.

Choi, S.; Lee, J. G.; Guo, F.; Bieler, T. R.; Subramanian, K. N.; Lucas, J. P.

2001-06-01

386

Development of cryogenic rotatable heat transfer joints  

Microsoft Academic Search

A summary of cryogenic rotatable heat transfer joint technology development, at Rockwell International Space Division, is presented. Starting with the flight qualified radiative joint on the RM-20B IR sensor of the early 70's, leading to rotatable heat pipe joint, gas conductive joints, rolling-contact-conductance joints, and the more recent work on development and evaluation of cryogenic rotatable seals and mechanical interfaces.

J. A. Sadunas; Z. F. Backovsky; D. E. Wilson

1992-01-01

387

Prosthetic Joint Infections in Elderly Patients  

Microsoft Academic Search

Although prosthetic joint infections (PJIs) occur in a small proportion of patients following total joint arthroplasty, they\\u000a have catastrophic consequences on morbidity and joint function and carry a high economic burden in the elderly patients.\\u000a \\u000a Clinical presentation of prosthetic joint infection is highly variable, and differentiating a painful joint arthroplasty secondary\\u000a to mechanical loosening from an indolent infection can be

Camelia E Marculescu; Elie F. Berbari; Douglas R. Osmon

388

Fatigue strength improvement of MIG-welded joint by shot peening  

Microsoft Academic Search

In this study, the effect of controlled shot peening (CSP) treatment on the fatigue strength of an ASTM A516 grade 70 carbon steel MIG-welded joint has been studied quantitatively. Metallurgical modifications, hardness, elemental compositions, and internal discontinuities, such as porosity and inclusions found in treated and untreated fusion welded joints, were characterized. The fatigue results of as-welded and peened skimmed

Nur Azida Che Lah; Aidy Ali

2011-01-01

389

Strength of Double Lap Joints Bonded With Carbon Black Reinforced Adhesive Under Cryogenic Environment  

Microsoft Academic Search

In order to improve the tensile lap shear strength and durability of adhesively bonded joints, nano-size carbon black particles were dispersed in the adhesive using a 3-roll mill. The effect of nano-particles on the mechanical properties of the adhesive and the lap shear strength of the adhesively bonded joints composed of glass\\/epoxy composite were investigated at room and cryogenic temperatures.

Sang Wook Park; Dai Gil Lee

2009-01-01

390

An analysis of a joint shear model for jointed media with orthogonal joint sets; Yucca Mountain Site Characterization Project  

SciTech Connect

This report describes a joint shear model used in conjunction with a computational model for jointed media with orthogonal joint sets. The joint shear model allows nonlinear behavior for both joint sets. Because nonlinear behavior is allowed for both joint sets, a great many cases must be considered to fully describe the joint shear behavior of the jointed medium. An extensive set of equations is required to describe the joint shear stress and slip displacements that can occur for all the various cases. This report examines possible methods for simplifying this set of equations so that the model can be implemented efficiently form a computational standpoint. The shear model must be examined carefully to obtain a computationally efficient implementation that does not lead to numerical problems. The application to fractures in rock is discussed. 5 refs., 4 figs.

Koteras, J.R.

1991-10-01

391

Breathing and temporomandibular joint disease.  

PubMed

Temporomandibular joint disease (TMD) refers to a collection of pain related conditions in the masticatory muscles and temporomandibular joint. Occlusal factors have been implicated in TMD pathogenesis, yet despite decades of research no causal relationship between occlusion and TMD has been found. The significance of psychosocial factors in both the assessment and the long-term management of patients with TMD is receiving increased recognition. The teaching of relaxation skills and coping strategies are effective, proven TMD therapies. The role of breathing re-education in temporomandibular joint (TMJ) disorders is rarely mentioned. A focus on breathing patterns and their disorders potentially explains how biomechanical factors associated with psychosocial influences might lead to pathophysiological changes within the TMJ as well as in the associated muscles. Attention to factors such as breathing and postural rehabilitation provides health professionals valuable, additional tools to help care for patients with TMD. PMID:21665104

Bartley, Jim

2010-06-25

392

Periprosthetic joint infection: Current concept.  

PubMed

Periprosthetic joint infection (PJI) is one of the most devastating and costly complications following total joint arthroplasty (TJA). Diagnosis and management of PJI is challenging for surgeons. There is no "gold standard" for diagnosis of PJI, making distinction between septic and aseptic failures difficult. Additionally, some of the greatest difficulties and controversies involve choosing the optimal method to treat the infected joint. Currently, there is significant debate as to the ideal treatment strategy for PJI, and this has led to considerable international variation in both surgical and nonsurgical management of PJI. In this review, we will discuss diagnosis and management of PJI following TJA and highlight some recent advances in this field. PMID:23531512

Aggarwal, Vinay K; Rasouli, Mohammad R; Parvizi, Javad

2013-01-01

393

Arthroscopy of the Sternoclavicular Joint  

PubMed Central

Traditionally, an open approach has been required to undertake any surgical intervention for intra-articular sternoclavicular joint pathology. This in itself carries a certain operative morbidity, including damage to the underlying mediastinal structures and damage to the sternoclavicular and costoclavicular ligaments, with subsequent joint instability and unsightly scarring. This technical note describes an arthroscopic approach to the sternoclavicular joint that reduces this morbidity. The evolution of the technique including the rationale for portal placement and the angle of instrument insertion is explained. Experience of over 50 arthroscopic procedures including diagnostic arthroscopy, discectomy, excision of loose bodies, and washout and debridement after infection and excision of the medial end of the clavicle for osteoarthritis is detailed.

Tytherleigh-Strong, Graham

2013-01-01

394

Superconducting joint of Bi-2223/Ag superconducting tapes by diffusion bonding  

NASA Astrophysics Data System (ADS)

61-Filaments Bi-2223/Ag superconducting tapes have been joined by diffusion bonding. The critical currents (ICs) of the joints are obtained by using standard four probe method under no magnetic field in the liquid nitrogen. The microstructures of the joints are evaluated by the electron microscope in electron backscatter diffraction mode and the phase compositions of the superconducting cores of the joint and the original tape are determined by X-ray diffraction (XRD). The results show diffusion bonding is effective bonding technique for HTS tapes, and the bonding time is reduced greatly from hundreds of hours to a few hours, and the bonding pressure also changes from 140-4000 MPa to 3 MPa. Furthermore, the diffusion bonding joints sustain superconducting properties, and the critical current ratios (CCRO) of the joints are in the range of 35%-80%. Microstructures of the typical joint display a good bonding and some defects existed in traditional method are avoided. XRD results show that the phase compositions of the superconducting cores have no obvious changes before and after diffusion bonding, which offers physical and material bases for high superconducting property of the joints.

Guo, Wei; Zou, Guisheng; Wu, Aiping; Wang, Yanjun; Bai, Hailin; Ren, Jialie

2009-11-01

395

A new finger joint prosthesis.  

PubMed

A new finger joint prosthesis is being developed for the proximal and distal interphalangeal positions. Currently available "joint spacer" prostheses provide relief from pain and cosmetic improvement, but relatively poor long-term function. The new prosthesis employs a mechanical hinge at the joint. It is fabricated from titanium alloy (6A14V). The hinge mechanism avoids direct metal to metal contact by using high density polyethylene bearings. In vitro tests of the hinge mechanism have passed 75 million cycles of continuous flexure without failure (n = 12). The hinge also incorporates a mechanical limit stop to prevent hyperextension. The hinge mechanism is enclosed in a sealed elastomeric jacket that isolates the hinge from connective tissue ingrowth. The jacket, equivalent to an artificial synovial membrane, has an integrally textured exterior surface designed to promote tissue attachment to the implant to stabilize tissue capsule formation around the joint. To test the in vivo efficacy of the new design, a series of 12 devices were implanted in the knee joint position of adult rabbits. A jacketed prosthesis was implanted on one side, whereas 2 weeks later an unjacketed control was implanted contralaterally. The animals then were maintained for an 8 week period. At sacrifice, the implants were removed, and the response of the surrounding tissues was studied histologically. At the time of implantation, the range of motion of the joints was approximately 100-105 degrees. There was a progressive loss in range of motion observed in both groups. The fibrous tissue capsule around the jacketed implants, however, was significantly reduced in thickness compared with the controls (mean thickness, 1.5 mm vs. 4.5 mm).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8268583

Whalen, R L; Bowen, M A; Sarrasin, M J; Fukumura, F; Harasaki, H

396

Putting the 'O' in Joint DOTMLPF: Organizational Capabilities for Joint Task Force Command and Control.  

National Technical Information Service (NTIS)

Across the defense establishment joint transformation is beginning to take hold though unevenly. Sweeping changes concerning joint doctrine training leader development acquisition, and facilities have taken effect under joint purview and direction through...

J. F. Dickens

2005-01-01

397

Temporomandibular joint disorders in children.  

PubMed

A child's difficulty in verbalizing the precise location and nature of facial pain and jaw dysfunction often results in a nondefinitive history, increasing the importance of the dentist's awareness of the early signs and symptoms of temporomandibular joint disorders (TMD). A focused examination of the masticatory musculature, the temporomandibular joints, and associated capsular and ligamentous structures can reveal if a patient's symptoms are TMD in origin. An accurate differential diagnosis enables timely referral to appropriate health care providers and minimizes the use of diagnostic imaging. PMID:23174613

Howard, James A

2013-01-01

398

Joint bioaccumulation and joint biological activity as ecotoxicological risk indicators  

Microsoft Academic Search

In this contribution, mathematical formulae for the estima- tion of thusly defined indicators are presented. Strategies for assessing biological activity from simultaneous mea- surements of biological effects and internal exposure are given special attention. Relevance of transformation products The question which of the known or suspected transforma- tion products should be included in an assessment of joint persistence (4), secondary

J. Ranke

399

Composite Parameters and Mechanical Compatibility of Material Joints  

Microsoft Academic Search

The elastic behaviour of a bimaterial interface with interfacial cracks, misfit dislocations and interfacial thermal stresses can be described in a simple manner by using the com posite parameters ? and ?, and the effective modulus of elasticity E*, assuming a plane deformation of ideally bonded isotropic materials. A coefficient KT for the thermally in duced stress intensity at the

T. Suga; G. Elssner; S. Schmauder

1988-01-01

400

Knee joint replacement - series (image)  

MedlinePLUS

The knee is a complex joint. It contains the distal end of the femur (the femoral condyles) and the ... The most common cause of knee damage that leads to knee replacement ... is a degenerative disease of the bones of the knee. It causes ...

401

DYNAMIC FRACTURE OF WELDED JOINTS  

Microsoft Academic Search

This paper presents an experimental and analytical investigation of dynamic fracture of T-shaped welded joints (stiffener on a plate) in a high strength steel. A fracture test was designed in which strain rates of several thousand per second can be reached in the weldment region by loading the specimen with tamped explosive. Test conditions can be reliably controlled by adjusting

J. H. GIOVANOLA; R. W. KLOPP; S. W. KIRKPATRICK; W. W. McDONALD

1991-01-01

402

The Strength of Adhesive Joints  

Microsoft Academic Search

The main rules pertaining to the strength of adhesive joints are: (1) This strength is a mechanical (or rheological) property. The local stress which causes the extension of a pre-existing crack can be determined only if the stress pattern in the whole adhint is known and the intensification of stress at flaws is taken into account. (2) The rupture occurs

J. J. Bikerman

1972-01-01

403

Joint Operational Access Concept (JOAC).  

National Technical Information Service (NTIS)

This paper proposes a concept for how joint forces will achieve operational access in the face of armed opposition by a variety of potential enemies and under a variety of conditions, as part of a broader national approach. Operational access is the abili...

2012-01-01

404

Automatic Locking Knee Brace Joint.  

National Technical Information Service (NTIS)

This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis t...

B. Weddendorf

1995-01-01

405

Trends in biological joint resurfacing  

PubMed Central

The treatment of osteochondral lesions and osteoarthritis remains an ongoing clinical challenge in orthopaedics. This review examines the current research in the fields of cartilage regeneration, osteochondral defect treatment, and biological joint resurfacing, and reports on the results of clinical and pre-clinical studies. We also report on novel treatment strategies and discuss their potential promise or pitfalls. Current focus involves the use of a scaffold providing mechanical support with the addition of chondrocytes or mesenchymal stem cells (MSCs), or the use of cell homing to differentiate the organism’s own endogenous cell sources into cartilage. This method is usually performed with scaffolds that have been coated with a chemotactic agent or with structures that support the sustained release of growth factors or other chondroinductive agents. We also discuss unique methods and designs for cell homing and scaffold production, and improvements in biological joint resurfacing. There have been a number of exciting new studies and techniques developed that aim to repair or restore osteochondral lesions and to treat larger defects or the entire articular surface. The concept of a biological total joint replacement appears to have much potential. Cite this article: Bone Joint Res 2013;2:193–9.

Myers, K. R.; Sgaglione, N. A.; Grande, D. A.

2013-01-01

406

Human Zygapophyseal Joint Synovial Folds  

Microsoft Academic Search

The structure of human zygapophyseal joint synovial folds as seen by high-power light microscopy and transmission electron microscopy is described. Small myelinated nerves are demonstrated in association with some capillaries in the synovial folds. This may have clinical significance in the field of spinal pain.Copyright © 1986 S. Karger AG, Basel

L. G. F. Giles; J. R. Taylor; A. Cockson

1986-01-01

407

Cryopumping field joint can testing  

NASA Astrophysics Data System (ADS)

For long installations, vacuum jacketed piping often comes in 40 foot sections that are butt welded together in the field. A short can is then welded over the bare pipe connection to allow for insulation to be protected from the environment. Traditionally, the field joint is insulated with multilayer insulation and a vacuum is pulled on the can to minimize heat leak through the bare section and prevent frost from forming on the pipe section. The vacuum jacketed lines for the Ares I mobile launch platform were to be a combined 2000 feet long, with 60+ pipe sections and field joint cans. Historically, Kennedy Space Center has drilled a hole in the long sections to create a common vacuum with the field joint can to minimize maintenance on the vacuum jacketed piping. However, this effort looked at ways to use a passive system that didn't require a vacuum, but may cryopump to create its own vacuum. Various forms of aerogel, multilayer insulations, and combinations thereof were tested to determine the best method of insulating the field joint while minimizing maintenance and thermal losses.

Johnson, Wesley; Fesmire, James; Meneghelli, Barry

2012-06-01

408

The Rationale for Joint Mobilization.  

ERIC Educational Resources Information Center

|This paper presents an overview of the functions of connective tissue and the mechanisms of joint injury and contracture formation in relation to therapeutic exercise. The components of connective tissue operation are explained, including fibroblasts, macrophages, plasma cells, and collagen. An examination of the histology of connective tissue as…

Burkhardt, Sandy

409

Joint Civilian Orientation Conference Program.  

National Technical Information Service (NTIS)

We reviewed whether the Assistant Secretary of Defense (Public Affairs) (ASD(PA)) administered the Joint Civilian Orientation Conference (JCOC) program in accordance with public law and DoD policies. This is the third in a series of audits conducted at th...

2009-01-01

410

Deterministic joint remote state preparation  

Microsoft Academic Search

We put forward a new nontrivial three-step strategy to execute joint remote state preparation via Einstein-Podolsky-Rosen pairs deterministically. At variance with all existing protocols, in ours the receiver contributes actively in both preparation and reconstruction steps, although he knows nothing about the quantum state to be prepared.

Nguyen Ba An; Cao Thi Bich; Nung Van Don

2011-01-01

411

Deterministic joint remote state preparation  

Microsoft Academic Search

We put forward a new nontrivial three-step strategy to execute joint remote state preparation via Einstein–Podolsky–Rosen pairs deterministically. At variance with all existing protocols, in ours the receiver contributes actively in both preparation and reconstruction steps, although he knows nothing about the quantum state to be prepared.

Nguyen Ba An; Cao Thi Bich; Nung Van Don

2011-01-01

412

Deterministic joint remote state preparation  

NASA Astrophysics Data System (ADS)

We put forward a new nontrivial three-step strategy to execute joint remote state preparation via Einstein-Podolsky-Rosen pairs deterministically. At variance with all existing protocols, in ours the receiver contributes actively in both preparation and reconstruction steps, although he knows nothing about the quantum state to be prepared.

An, Nguyen Ba; Bich, Cao Thi; Don, Nung Van

2011-09-01

413

Arthrodesis of the Trapeziometacarpal Joint  

Microsoft Academic Search

Over a 10-year period, 32 trapeziometacarpal (TM) joint fusions were performed in 29 patients, and reviewed. Pin fixation with tension band wiring was used in 14 cases, screws in eight cases, a plate in six cases, K-wires in three cases and staple fixation in one case. None was bone grafted. Splinting was applied for 4 to 5 weeks. There were

A. CHAMAY; F. PIAGET-MOREROD

1994-01-01

414

Joint calibration of multiple sensors  

Microsoft Academic Search

Many calibration methods calibrate a pair of sensors at a time. For robotic systems with many sensors, they are often time-consuming to use, and can also lead to inaccurate results. In this paper, we combine a number of ideas in the literature to derive a unified framework that jointly calibrates many sensors a large system. Key to our approach are

Quoc V. Le; Andrew Y. Ng

2009-01-01

415

A study of fastener pull-through failure of composite laminates. Part 1: Experimental  

Microsoft Academic Search

Of the extensive number of investigations examining mechanically fastened composite joints, all but a few are limited to consideration of in-plane modes of failure. An experimental and numerical investigation of fastener pull-through failure of composite joints has therefore been undertaken. The experimental program included an investigation of the influence fastener head geometry, laminate thickness, stacking sequence and material system have

A Banbury; D. W Kelly

1999-01-01

416

Function of stiff joints may be restored by Ilizarov joint distraction.  

PubMed

Three patients with joint stiffness caused by trauma or infection are reported. The involved joints are the interphalangeal joint of the thumb, patellofemoral joint, and ankle joint. As an alternative for the indicated arthrodesis in these patients, treatment with articulating joint distraction was performed. By use of adapted Ilizarov external ring fixators, gradual distraction was applied to loosen the joint, followed after loosening by a period of exercise during distraction. In all three patients this experimental approach led to a decrease in pain and improvement of joint function that persisted for at least 2 years after treatment. With the use of Ilizarov joint distraction, joint function in cases of joint stiffness may be restored, and the need for an arthrodesis can be postponed. PMID:9553556

van Roermund, P M; van Valburg, A A; Duivemann, E; van Melkebeek, J; Lafeber, F P; Bijlsma, J W; Verbout, A J

1998-03-01

417

Joint Bayesian analysis of forensic mixtures.  

PubMed

Evaluation of series of PCR experiments referring to the same evidence is not infrequent in a forensic casework. This situation is met when 'series of results in mixture' (EPGs produced by reiterating PCR experiments over the same DNA mixture extract) have to be interpreted or when 'potentially related traces' (mixtures that can have contributors in common) require a combined interpretation. In these cases, there can be uncertainty on the genotype assignment, since: (a) more than one genotype combination fall under the same peak profile; (b) PCR preferential amplification alters pre-PCR allelic proportions; (c) other, more unpredictable technical problems (dropouts/dropins, etc.) take place. The uncertainty in the genotype assignment is in most cases addressed by empirical methods (selection of just one particular profile; extraction of consensual or composite profiles) that disregard part of the evidence. Genotype assignment should conversely take advantage from a joint Bayesian analysis (JBA) of all STRs peak areas generated at each experiment. This is the typical case of Bayesian analysis in which adoption of object-oriented Bayesian networks (OOBNs) could be highly helpful. Starting from experimentally designed mixtures, we created typical examples of 'series of results in mixture' of 'potentially related traces'. JBA was some administered to the whole peak area evidence, by specifically tailored OOBNs models, which enabled genotype assignment reflecting all the available evidence. Examples of a residual ambiguity in the genotype assignment came to light at assumed genotypes with partially overlapping alleles (for example: AB+AC?ABC). In the 'series of results in mixture', this uncertainty was in part refractory to the joint evaluation. Ambiguity was conversely dissipated at the 'potentially related' trace example, where the ABC allelic scheme at the first trace was interpreted together with other unambiguous combinations (ABCD; AB) at the related trace. We emphasize the need to carry out extensive, blind sensitivity tests specifically addressing the residual ambiguity that arises from overlapping results mixed at various quantitative ratios. PMID:22948016

Pascali, Vince L; Merigioli, Sara

2012-09-01

418

Time- and temperature-dependent failures of a bonded joint  

NASA Astrophysics Data System (ADS)

This dissertation summarizes my study of time- and temperature-dependent behavior of a tubular lap bonded joint to provide a design methodology for windmill blade structures. The bonded joint is between a cast-iron rod and a GFRP composite pipe. The adhesive material is an epoxy containing chopped glass fibers. We proposed a new fabrication method to make concentric and void-less specimens of the tubular joint with a thick adhesive bondline to stimulate the root bond of a blade. The thick bondline facilitates the joint assembly of actual blades. For a better understanding of the behavior of the bonded joint, we studied viscoelastic behavior of the adhesive materials by measuring creep compliance at several temperatures during loading period. We observed that the creep compliance depends highly on the period of loading and the temperature. We applied time-temperature equivalence to the creep compliance of the adhesive material to obtain time-temperature shift factors. We also performed constant-rate of monotonically increased uniaxial tensile tests to measure static strength of the tubular lap joint at several temperatures and different strain-rates. We observed two failure modes from load-deflection curves and failed specimens. One is the brittle mode, which was caused by weakness of the interfacial strength occurring at low temperature and short period of loading. The other is the ductile mode, which was caused by weakness of the adhesive material at high temperature and long period of loading. Transition from the brittle to the ductile mode appeared as the temperature or the loading period increased. We also performed tests under uniaxial tensile-tensile cyclic loadings to measure fatigue strength of the bonded joint at several temperatures, frequencies and stress ratios. The fatigue data are analyzed statistically by applying the residual strength degradation model to calculate statistical distribution of the fatigue life. Combining the time-temperature equivalence and the residual strength degradation model enables us to estimate the fatigue life of the bonded joint at different load levels, frequencies and temperatures with a certain probability. A numerical example shows how to apply the life estimation method to a structure subjected to a random load history by rainflow cycle counting.

Sihn, Sangwook

419

29 CFR 791.2 - Joint employment.  

Code of Federal Regulations, 2013 CFR

...REGULATIONS JOINT EMPLOYMENT RELATIONSHIP UNDER FAIR LABOR STANDARDS ACT OF 1938 § 791.2 Joint employment. ...two or more employers at the same time under the Fair Labor Standards Act of 1938, since there is nothing in the...

2013-07-01

420

Simplifying Bridge Expansion Joint Design and Maintenance.  

National Technical Information Service (NTIS)

This report presents a study focused on identifying the most durable expansion joints for the South Carolina Department of Transportation. This is performed by proposing a degradation model for the expansion joints and updating it based on bridge inspecti...

D. Rizos G. Wieger J. M. Caicedo P. Ziehl

2011-01-01

421

30 CFR 36.24 - Engine joints.  

Code of Federal Regulations, 2013 CFR

...PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.24 Engine joints. (a) Cylinder head. The joint between the cylinder head and block of the engine shall be...

2013-07-01

422

38 CFR 4.66 - Sacroiliac joint.  

Code of Federal Regulations, 2010 CFR

...changes from arthritis in this location are decrease or obliteration of the joint space, with the appearance of increased bone density of the sacrum and ilium and sharpening of the margins of the joint. Disability is manifest from erector spinae...

2010-07-01

423

38 CFR 4.66 - Sacroiliac joint.  

Code of Federal Regulations, 2010 CFR

...changes from arthritis in this location are decrease or obliteration of the joint space, with the appearance of increased bone density of the sacrum and ilium and sharpening of the margins of the joint. Disability is manifest from erector spinae...

2009-07-01

424

38 CFR 4.66 - Sacroiliac joint.  

Code of Federal Regulations, 2013 CFR

...changes from arthritis in this location are decrease or obliteration of the joint space, with the appearance of increased bone density of the sacrum and ilium and sharpening of the margins of the joint. Disability is manifest from erector spinae...

2013-07-01

425

49 CFR 583.15 - Joint ownership.  

Code of Federal Regulations, 2012 CFR

...Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AUTOMOBILE PARTS CONTENT LABELING § 583.15 Joint ownership. (a) A carline jointly owned and/or produced by more...

2012-10-01

426

Predicting variability in joint frequencies from boreholes  

NASA Astrophysics Data System (ADS)

Joints in rock are not evenly spaced, but commonly show clustering. This suggests that boreholes that are a short distance apart can intersect very different numbers of joints. A simple 1D model is used to illustrate variability in joint frequencies from vertical wells intersecting steeply dipping joints. The model indicates that raw joint frequencies logged from core or borehole images can give unreliable inputs into reservoir models, especially when the joints are clustered and variations occur over scales that are much smaller than the resolution of seismic surveys or the grid blocks used in reservoir simulations. Variability in joint frequencies from deviated or horizontal wells can be used, however, to test the variability in joint frequencies from vertical wells.

Peacock, D. C. P.

2006-02-01

427

Joint Operations and the Vicksburg Campaign.  

National Technical Information Service (NTIS)

This historical study investigates why Union joint operations between army and navy forces on the Mississippi and other western rivers were effective. It examines the development of a joint doctrine at the strategic, operational, and tactical levels of wa...

J. W. Tindall

1993-01-01

428

Joint Lessons Learned System and Interoperability.  

National Technical Information Service (NTIS)

This study analyzes the evolution of the Joint Lessons Learned System. It examines historical evidence of interoperability issues in US joint military operations from World War II to the present. Three major conflicts: World War II, Korea, and Vietnam, ar...

A. D. Landry

1989-01-01

429

Bone, Joint, and Muscle Infections in Children  

MedlinePLUS

... American Academy of Orthopaedic Surgeons Bone, Joint, and Muscle Infections in Children Children can develop infections in their bones, joints, or muscles. Often referred to as "deep" infections, the technical ...

430

Joint Operations at Vicksburg: The Decisive Force.  

National Technical Information Service (NTIS)

The joint operations employed in the Civil War provide valuable lessons to all military leaders involved in planning and executing future campaigns. This paper analyzes the extent and results of the joint operations developed and implemented by the Union ...

C. A. Hazard

2002-01-01

431

Strength of profile-adhesive joints  

Microsoft Academic Search

The current article presents an attempt to describe the strength of profile-adhesive joints. Its main objective was to develop\\u000a mathematical models describing phenomena occurring in bent mortise joints prevalent in constructions of skeleton furniture,\\u000a but also to determine factors influencing the strength of profile-adhesive joints. The presented cases of gluing of a mortise\\u000a joint reveal that mutual interactions of compressed

J. Smardzewski

2002-01-01

432

Predictions of solder joint fatigue life  

Microsoft Academic Search

Procedures used to predict solder-joint life from calculations of the joint strains and low-cycle fatigue data are described. The fatigue lives of chip-carrier\\/printed-wiring-board joints are predicted and compared to measured values. This prediction utilizes a finite-element analysis of the string distributions in a typical joint acted upon by an imposed displacement. These strains are then used to determine the fatigue

H. D. Solomon; V. Brzozowski; D. G. Thompson

1990-01-01

433

Radioulnar joint fusion for distal radioulnar joint instability.  

PubMed

Each one of this small group of patients illustrates a rare indication for the radioulnar joint fusion procedure in distal radioulnar joint instability. The case histories tell of a last ditch effort to salvage function in an extremity crippled by painful radioulnar instability after excision of the distal ulna. The fusions healed slowly and two required repeat surgery to achieve union. Today we would routinely add iliac bone graft to the fusion area to hasten healing. Rarely indicated, this is a salvage procedure that is done after failure of other procedures geared to preserve the rotation of the forearm. These patients all had successful salvage of their extremities for activities of daily living, but only one returned to his labor job. All were worker's compensation cases in physical jobs. Two patients had had prior radiocarpal fusions, making them even more restricted in function. This procedure should be kept in mind to be used in the rare cases of painful instability of the distal radioulnar joint when traditional motion-preserving procedures have failed. PMID:1880172

Schneider, L H; Imbriglia, J E

1991-05-01

434

Seismic response of rock joints and jointed rock mass  

SciTech Connect

Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts and the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs.

Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

1996-06-01

435

Radiofrequency sacroiliac joint denervation for sacroiliac syndrome  

Microsoft Academic Search

Background and Objectives: Radiofrequency (RF) denervation of the sacroiliac (SI) joint has been advocated for the treatment of sacroiliac syndrome, yet no clinical studies or case series support its use. Methods: We report the results of a consecutive series of 50 SI joint RF denervations performed in 33 patients with sacroiliac syndrome. All patients underwent diagnostic SI joint injections with

F. Michael Ferrante; Lawrence F. King; Elizabeth A. Roche; Philip S. Kim; Margaret Aranda; Leslie R. DeLaney; Issam A. Mardini; Andrew J. Mannes

2001-01-01

436

The frictional properties of joints in rock  

Microsoft Academic Search

Summary The conditions for sliding over artificial joint surfaces have been studied experimentally by cutting rock cylinders at various angles to their axes and studying slip over these surfaces in a triaxial testing apparatus. The types of joint used were: (i) filled with plaster to simulate a soft joint filling, (ii) bare surfaces ground approximately flat, and (iii) natural surfaces

J. C. Jaeger

1959-01-01

437

17 CFR 300.105 - Joint accounts.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Joint accounts. 300.105 Section 300.105 ...SECURITIES INVESTOR PROTECTION CORPORATION Accounts of âseparateâ Customers of Sipc Members § 300.105 Joint accounts. (a) A joint account shall be...

2013-04-01

438

49 CFR 234.233 - Rail joints.  

Code of Federal Regulations, 2011 CFR

... 4 2011-10-01 2011-10-01 false Rail joints. 234.233 Section 234.233 Transportation...Testing Maintenance Standards § 234.233 Rail joints. Each non-insulated rail joint located within the limits of a...

2011-10-01

439

49 CFR 234.233 - Rail joints.  

Code of Federal Regulations, 2012 CFR

... 4 2012-10-01 2012-10-01 false Rail joints. 234.233 Section 234.233 Transportation...Testing Maintenance Standards § 234.233 Rail joints. Each non-insulated rail joint located within the limits of a...

2012-10-01

440

Septic arthritis of the acromioclavicular joint  

Microsoft Academic Search

A patient with isolated pyogenous arthritis of the acromioclavicular joint (A-C joint) caused by Streptococcus viridans is described. The patient had no underlying disease. Minor trauma preceded shortly the development of the septic process. The patient was treated successfully with surgical drainage and antibiotics. To our knowledge this is the first case report of septic arthritis of the A-C joint

A. Blankstein; J. L. Amsallem; E. Rubinstein; H. Horoszowski; I. Farin

1985-01-01

441

Failure Assessment Diagram for Titanium Brazed Joints.  

National Technical Information Service (NTIS)

The interaction equation was used to predict failure in Ti-4V-6Al joints brazed with Al 1100 filler metal. The joints used in this study were geometrically similar to the joints in the brazed beryllium metering structure considered for the ATLAS telescope...

D. F. Puckett J. S. Jones M. M. Powell Y. Flom

2011-01-01

442

Computer simulation of solder joint failure  

Microsoft Academic Search

The thermomechanical fatigue failure of solder joints is increasingly becoming an important reliability issue for electronic packages. The purpose of this Laboratory Directed Research and Development (LDRD) project was to develop computational tools for simulating the behavior of solder joints under strain and temperature cycling, taking into account the microstructural heterogeneities that exist in as-solidified near eutectic Sn-Pb joints, as

S. N. Burchett; D. R. Frear; M. M. Rashid

1997-01-01

443

The joint behaviors of intelligent agents  

Microsoft Academic Search

Joint behaviors widely existing in intelligent systems are important to investigate the cooperation among intelligent agents. In this paper, we put forward a comprehensive and novel model of joint behaviors in support of analysis and design of intelligent systems. The model includes two kinds of joint behaviors, their formal semantics are defined, and important properties are discussed, specified and proved.

Xinjun Mao; Huaiming Wang; Gang Wu

2003-01-01

444

Prediction of Solder Joint Fatigue Life.  

National Technical Information Service (NTIS)

This study details the procedures used to predict the solder joint life from calculations of the joint strains and low-cycle fatigue data. The fatigue life of chip carrier/printed wiring board joints are predicted and compared to measured values. This pre...

D. G. Thompson H. D. Solomon V. Brzozowski

1988-01-01

445

New insights in critical solder joint location  

Microsoft Academic Search

Current numerical modeling approaches to assess BGA solder joint thermal mechanical fatigue, typically identify the max DNP (distance from neutral point) solder joint as the first to fail. An experimental and numerical analysis has shown that critical solder joints can be located interior to the max DNP location. In this work, FCBGA packages were subjected to accelerated thermal cycling stress.

Mitul Modi; Carolyn McCormick; Norman Armendariz

2005-01-01

446

PROSTHETIC JOINT INFECTION DUE TO HAEMOPHILUS APHROPHILUS  

Microsoft Academic Search

A case of prosthetic joint infection due to Haemophilus aphrophilus is presented. A 76-year-old woman, with a long history of pain in her left hip and raised inflammatory markers, underwent prosthetic joint excision. Six samples of pus and tissue were taken from the joint and Haemophilus aphrophilus was cultured from 3 of these specimens. We review the clinical and microbiological

447

Russian upstream joint ventures logging progress  

SciTech Connect

This paper reports that Occidental Petroleum Corp. has begun exporting oil from Russia as part of an enhanced recovery joint venture in western Siberia. Oxy holds a 50% interest in the joint venture company, Vanyoganneft, and will market the oil. In other activity, two Canadian companies are marking progress with Russian upstream joint ventures.

Not Available

1992-11-02

448

Static model of pneumatic flexible rotary joint  

Microsoft Academic Search

Service robot, bionic robot and agricultural robot must directly contact with organism, which requires high security and adaptability. Flexible pneumatic actuators and joints can meet this demand. A type of flexible pneumatic rotary joint is proposed in this paper, based on the flexible pneumatic actuator FPA. The rotation movement is realized by inflating and deflating the rotary joint chamber. According

Guanjun Bao; Qinghua Yang; Shanghui Li; Libin Zhang

2009-01-01

449

Corrosion Issues in Solder Joint Design and Service  

SciTech Connect

Corrosion is an important consideration in the design of a solder joint. It must be addressed with respect to the service environment or, as in the case of soldered conduit, as the nature of the medium being transported within piping or tubing. Galvanic-assisted corrosion is of particular concern, given the fact that solder joints are comprised of different metals or alloy compositions that are in contact with one-another. The (thermodynamic) potential for corrosion to take place in a particular environment requires the availability of the galvanic series for those conditions and which includes the metals or alloys in question. However, the corrosion kinetics, which actually determine the rate of material loss under the specified service conditions, are only available through laboratory evaluations or field data that are found in the existing literature or must be obtained by in-house testing.

VIANCO,PAUL T.

1999-11-24

450

Autologous fat grafts placed around temporomandibular joint total joint prostheses to prevent heterotopic bone formation  

Microsoft Academic Search

This study evaluated 1) the efficacy of packing autologous fat grafts around temporomandibular joint (TMJ) total joint prosthetic reconstruc- tions to prevent fibrosis and heterotopic bone formation and 2) the ef- fects on postsurgical joint mobility and jaw function. One hundred fifteen patients (5 males and 110 females) underwent TMJ reconstruction with total joint prostheses and simultaneous fat grafts (88

Larry M. Wolford; Carlos A. Morales-Ryan; Patricia Garcia Morales; Daniel Serra Cassano

451

Autologous fat transplantation around temporomandibular joint total joint prostheses: Preliminary treatment outcomes  

Microsoft Academic Search

Purpose: This study evaluated the efficacy of autologous fat grafting to the temporomandibular joint (TMJ) as an adjunct to prosthetic joint reconstruction in preventing fibrosis and heterotopic bone formation and determined its effects on postoperative joint mobility.Patients and Methods: Fifteen patients (2 male, 13 female) underwent TMJ reconstruction with Techmedica (Techmedica, Inc, Camarillo, CA) custom-made total joint prostheses. Seven patients

Larry M Wolford; Spiro C Karras

1997-01-01

452

In vivo human knee joint dynamic properties as functions of muscle contraction and joint position  

Microsoft Academic Search

Information on the dynamic properties (joint stiffness, viscosity and limb inertia) of the human knee joint is scarce in the literature, especially for actively contracting knee musculature. A joint driving device was developed to apply small-amplitude random perturbations to the human knee at several flexion angles with the subject maintaining various levels of muscle contraction. It was found that joint

Li-Qun Zhang; Gordon Nuber; Jesse Butler; Mark Bowen; William Z. Rymer

1997-01-01

453

Proximal Tibiofibular Joint Ganglion CystsExcision, Recurrence, and Joint Arthrodesis  

Microsoft Academic Search

Objective: Proximal tibiofibular joint proximal tibiofibular joint cysts are rare entities that can cause disability. Excision remains the traditional surgical treatment. Cyst recurrence has been a problem. This study reviews one of the largest series of patients with proximal tibiofibular joint cysts and evaluates the role of a new surgical option, proximal tibiofibular joint fusion.Methods: Thirteen patients were admitted to

Shana Miskovsky; Christopher Kaeding; Lawrence Weis

2004-01-01

454

Complications of small joint arthroplasty.  

PubMed

Arthritis in the small joints of the hand can be treated with arthrodesis or arthroplasty. Arthrodesis has known risks of infection, pain, and nonunion. Distal interphalangeal (DIP) arthroplasty has been successful in preserving motion and alleviating pain for distal DIP, proximal interphalangeal, and metacarpophalangeal joints. Unfortunately, complications arise that limit the success of surgery. Silicone implants have been reliable for many years but still present with the risks of infection, implant breakage, stiffness, and pain. Newer implant designs may limit some of these complications, but present with unique problems such as dislocations and loosening. It is not yet clear as to which type of implant provides the most reliable results, although implant arthroplasty appears to give better function than arthrodesis. Silicone arthroplasty does not lead to silicone synovitis and is a reliable procedure. Pyrocarbon implants are showing some promise, particularly in the osteoarthritic patient. PMID:20494746

Drake, Matthew L; Segalman, Keith A

2010-05-01

455

Sonography of the knee joint?  

PubMed Central

The aim of this article is to review the sonographic appearances of common disorders involving the knee joint. Ultrasound is a sensitive method for diagnosis of tendon injuries. Injured ligaments appear swollen with mixed echogenicity. Meniscal injuries and muscle tears can be easily diagnosed. Ultrasound shows synovial thickening and effusion in inflammatory arthropathy and erosions of the articular surface in degenerative arthritis. It can be used effectively in the detection of rheumatoid arthritic activity and for grading degenerative arthritis lesions. Cystic lesions, as well as benign and malignant soft-tissue masses, are clearly delineated. Ultrasound is a safe noninvasive imaging modality that can be used for diagnosis of different disorders involving the knee joint.

Razek, A.A.K.A.; Fouda, N.S.; Elmetwaley, N.; Elbogdady, E.

2009-01-01

456

Hydraulic Fracturing of Jointed Formations  

Microsoft Academic Search

Measured by volume, North America's largest hydraulic fracturing operations have been conducted at Fenton Hill, New Mexico to create geothermal energy reservoirs. In the largest operation 21,000 m³ of water were injected into jointed granitic rock at a depth of 3.5 km. Microearthquakes induced by this injection were measured with geophones placed in five wells drilled into, or very close,

H. D. Murphy; M. C. Fehler

1986-01-01

457

Lubrication of the Temporomandibular Joint  

Microsoft Academic Search

Although tissue engineering of the temporomandibular joint (TMJ) structures is in its infancy, tissue engineering provides\\u000a the revolutionary possibility for treatment of temporomandibular disorders (TMDs). Recently, several reviews have provided\\u000a a summary of knowledge of TMJ structure and function at the biochemical, cellular, or mechanical level for tissue engineering\\u000a of mandibular cartilage, bone and the TMJ disc. As the TMJ

Eiji Tanaka; Michael S. Detamore; Kotaro Tanimoto; Nobuhiko Kawai

2008-01-01

458

Joint stabilizing projects in defense  

SciTech Connect

Joint defensive projects could increase stability and decrease the alert rates of strategic forces. Areas include the defense of the US, Commonwealth of Independent States (CIS), and their allies against third world threats; protection against each other`s accidental or unauthorized launches; and defense against intentional attacks. The most promising area appears to be defining interfaces for the handover of satellite warning and trajectory information, which applies to most phases of theater defense and mutual protection. 19 refs.

Canavan, G.H.; Browne, J.C.; Joseph, R.J.

1992-06-01

459

Joint stabilizing projects in defense  

SciTech Connect

Joint defensive projects could increase stability and decrease the alert rates of strategic forces. Areas include the defense of the US, Commonwealth of Independent States (CIS), and their allies against third world threats; protection against each other's accidental or unauthorized launches; and defense against intentional attacks. The most promising area appears to be defining interfaces for the handover of satellite warning and trajectory information, which applies to most phases of theater defense and mutual protection. 19 refs.

Canavan, G.H.; Browne, J.C.; Joseph, R.J.

1992-06-01

460

Mechanical flexible joint design document  

NASA Astrophysics Data System (ADS)

The purpose of this report is to document the status of the Mechanical Flexible Joint (MFJ) Design Subtask with the intent of halting work on the design. Recommendations for future work is included in the case that the task is to be resumed. The MFJ is designed to eliminate two failure points from the current flex joint configuration, the inner 'tripod configuration' and the outer containment jacket. The MFJ will also be designed to flex 13.5 degrees and have three degrees of freedom. By having three degrees of freedom, the MFJ will allow the Low Pressure Fuel Duct to twist and remove the necessity to angulate the full 11 degrees currently required. The current flex joints are very labor intensive and very costly and a simple alternative is being sought. The MFJ is designed with a greater angular displacement, with three degrees of freedom, to reside in the same overall envelope, to meet weight constraints of the current bellows, to be compatible with cryogenic fuel and oxidizers, and also to be man-rated.

Daily, Vic

1993-10-01

461

Analysis of NSTX TF Joint Voltage Measurements  

SciTech Connect

This report presents findings of analyses of recorded current and voltage data associated with 72 electrical joints operating at high current and high mechanical stress. The analysis goal was to characterize the mechanical behavior of each joint and thus evaluate its mechanical supports. The joints are part of the toroidal field (TF) magnet system of the National Spherical Torus Experiment (NSTX) pulsed plasma device operating at the Princeton Plasma Physics Laboratory (PPPL). Since there is not sufficient space near the joints for much traditional mechanical instrumentation, small voltage probes were installed on each joint and their voltage monitoring waveforms have been recorded on sampling digitizers during each NSTX ''shot''.

Woolley R

2005-10-07

462

Joint denervation and neuroma surgery as joint-preserving therapy for ankle pain.  

PubMed

Partial joint denervation or surgical neuroma therapy are alternative concepts to treat pain around the ankle joint that preserve joint function and relieve pain by interrupting neural pathways that transmit pain impulses from the joint to the brain. This review article summarizes the indication, anatomic background, operative techniques, and clinical results of joint denervation or neuroma surgery, which, although rarely reported and used, may provide a valuable alternative treatment in selected patients with neurogenous problems around the ankle. PMID:24008220

Gohritz, Andreas; Dellon, A Lee; Kalbermatten, Daniel; Fulco, Ilario; Tremp, Mathias; Schaefer, Dirk J

2013-09-01

463

Isothermal fatigue behavior of Sn--Pb solder joints  

SciTech Connect

Isothermal fatigue data were collected for the compositions 5Sn--95Pb, 20Sn--80Pb, 40Sn--60Pb, 50Sn--50Pb and 63Sn--37Pb within the binary Sn--Pb system. All of these compositions are commercially available and include those most commonly used. Because Sn-rich solders are rarely used, they were not investigated here. The fatigue life was defined by a 30% load drop. The solders were tested in a double shear configuration joined to copper at 75{degree}C. The displacement rate chosen was 0.01 mm/min, which corresponds to a strain rate of 1.5 {times} 10{sup {minus}4} s{sup {minus}1} for our specimen configuration, over a 10% plastic strain range. Additionally, the microstructural changes during fatigue are presented. The various solder compositions studied exhibit strikingly different as-solidified microstructures. These differences are discussed in terms of their effect on the isothermal joint failure mechanism and joint isothermal fatigue life. 24 refs., 10 figs.

Summers, T.S.E.; Morris, J.W. Jr.

1989-09-01

464

Nonoperative treatment of metatarsophalangeal joint synovitis.  

PubMed

The results of nonoperative treatment of metatarsophalangeal (MP) joint synovitis in 13 patients without known rheumatologic conditions (15 joints) were reviewed. Average duration of forefoot pain was 4 +/- 3 months (range 0.5-12 months), except for one patient who had pain for 30 months. The second MP joint was involved in nine cases (60%), and the third was involved in six cases (40%). Examination revealed tenderness and palpable fullness of the MP joint in all cases; painful dorsal drawer sign was present in 10 cases (67%), adjacent interdigital tenderness in six cases (40%), and hammertoe deformity in eight cases (53%). Treatment included intra-articular corticosteroid injection and rocker-sole show modification to limit MP joint dorsiflexion. At follow-up evaluation (18 +/- 9 months, range 4-26 months), the involved MP joint was asymptomatic in nine joints (60%), improved or almost asymptomatic in five joints (33%), and operated in one (7%) joint. Two of seven (29%) joints not initially associated with hammertoe developed a mild hammertoe deformity from time of diagnosis to follow-up. In conclusion, nonoperative treatment can be effective for MP joint synovitis, and the incidence of progressive hammertoe deformity in successfully treated cases is low. PMID:8749348

Trepman, E; Yeo, S J

1995-12-01

465

Effect of Ni-Coated Carbon Nanotubes on Interfacial Reaction and Shear Strength of Sn-Ag-Cu Solder Joints  

NASA Astrophysics Data System (ADS)

In this study, varying weight percentages of Ni-coated carbon nanotubes (Ni-CNTs) were incorporated into Sn-Ag-Cu (SAC) solder matrix, to form composite solder. Up to 0.05% of Ni-CNTs were successfully incorporated. The interfacial microstructure and shear strength of solders on Ni/Au-finished Cu substrates were investigated after aging at 150°C for up to 42 days. Results revealed that, after soldering and aging for various lengths of time, the interfacial intermetallic compound (IMC) thickness of the unreinforced solder joint was observed to grow more significantly than that of the composite solder joints. Furthermore, the composite solder joints also showed lower diffusion coefficients (2.5 × 10-15 cm2/s to 3.2 × 10-15 cm2/s) compared with that of the SAC solder joints (4.9 × 10-15 cm2/s). Shear test results revealed that as-soldered and aged composite solder joints had better ultimate shear strength than their monolithic counterparts and the shear strength of all aged solder joints decreased with increasing aging time.

Han, Y. D.; Jing, H. Y.; Nai, S. M. L.; Xu, L. Y.; Tan, C. M.; Wei, J.

2012-09-01

466

A Practical Test Method for Mode I Fracture Toughness of Adhesive Joints with Dissimilar Substrates  

SciTech Connect

A practical test method for determining the mode I fracture toughness of adhesive joints with dissimilar substrates will be discussed. The test method is based on the familiar Double Cantilever Beam (DCB) specimen geometry, but overcomes limitations in existing techniques that preclude their use when testing joints with dissimilar substrates. The test method is applicable to adhesive joints where the two bonded substrates have different flexural rigidities due to geometric and/or material considerations. Two specific features discussed are the use of backing beams to prevent substrate damage and a compliance matching scheme to achieve symmetric loading conditions. The procedure is demonstrated on a modified DCB specimen comprised of SRIM composite and thin-section, e-coat steel substrates bonded with an epoxy adhesive. Results indicate that the test method provides a practical means of characterizing the mode I fracture toughness of joints with dissimilar substrates.

Boeman, R.G.; Erdman, D.L.; Klett, L.B.; Lomax, R.D.

1999-09-27

467

Aging of defective electrical joints in underground power distribution systems  

Microsoft Academic Search

Electrical joints can be weak points in an underground distribution supply system. Cyclic loads and the fact that electrical joints are inside premolded rubber cable joints both greatly affect their reliability. Within the framework of a preventive maintenance program, we have studied the life expectancy of underground cable joints with defective electrical joints. Three types of cable joints were subjected

Daniel Fournier

1998-01-01

468

Fabrication and evaluation of SixNy coatings for total joint replacements.  

PubMed

Wear particles from the bearing surfaces of joint implants are one of the main limiting factors for total implant longevity. Si(3)N(4) is a potential wear resistant alternative for total joint replacements. In this study, Si(x)N(y)-coatings were deposited on cobalt chromium-discs and Si-wafers by a physical vapour deposition process. The tribological properties, as well as surface appearance, chemical composition, phase composition, structure and hardness of these coatings were analysed. The coatings were found to be amorphous or nanocrystalline, with a hardness and coefficient of friction against Si(3)N(4) similar to that found for bulk Si(3)N(4). The low wear rate of the coatings indicates that they have a potential as bearing surfaces of joint replacements. The adhesion to the substrates remains to be improved. PMID:22689010

Olofsson, J; Pettersson, M; Teuscher, N; Heilmann, A; Larsson, K; Grandfield, K; Persson, C; Jacobson, S; Engqvist, H

2012-06-12

469

Optimization of Pb-Free Solder Joint Reliability from a Metallurgical Perspective  

NASA Astrophysics Data System (ADS)

To obtain the desired performance of Pb-free packages in mechanical tests, while the solder composition should be carefully selected, the influence of metals dissolved from the soldering pad or under bump metallization (UBM) should also be taken into account. Dissolved metals such as Cu can alter the intermetallic compound (IMC) formation, not only at the local interface but also on the other side of the joint. The high rate of interfacial cracking of Sn-Ag-Cu solder joints on Ni/Au-plated pads is attributed to the high stiffness of the solder and the dual IMC structure of (Cu,Ni)6Sn5 on Ni3Sn4 at the interface. Approaches to avoid this dual IMC structure at the interface are discussed. A rule for selecting the solder alloy composition and the pad surface materials on both sides of the joints is proposed for ball grid array (BGA) packages.

Zeng, Kejun; Pierce, Mike; Miyazaki, Hiroshi; Holdford, Becky

2012-02-01

470

Retarding the electromigration effects to the eutectic SnBi solder joints by micro-sized Ni-particles reinforcement approach  

Microsoft Academic Search

Electromigration (EM) has become one of the reliability concerns to the electronic solder joint due to its increasing capacity to bear the high current density (104A\\/cm2). Although the failure induced by EM can trigger a large void across the entire cathode interface, no effective solutions are presented throughout years of effort on this problem. Here, the composite solder joints are

Guangchen Xu; Fu Guo; Xitao Wang; Zhidong Xia; Yongping Lei; Yaowu Shi; Xiaoyan Li

2011-01-01

471

Piezoelectric film sensor for measurement of peel stresses in bonded joints  

Microsoft Academic Search

Adhesively bonded composite patches employed for repairing fatigue cracks in metallic airframe structural components often fail under peel stress generated in the structure. The application of piezoelectric stress sensors embedded within the bonded joint for direct measurement of the peel stresses is reported here. Polyvinylidine fluoride (PVDF) film of about 28 micron thickness coated with nickel copper is employed to

Krishnakumar Shankar; Murat Tahtali; Richard Chester; Glen Torr

2001-01-01

472

Analytical and computational modeling of robotic fish propelled by soft actuation material-based active joints  

Microsoft Academic Search

Soft actuation materials, such as ionic polymer-metal composites (IPMCs), are gaining increasing interest in robotic applications since they lead to compact and biomimetic designs. In this paper, we propose the use of soft actuation materials as active joints for propelling biomimetic robotic fish. An analytical model is developed to compute the thrust force generated by a two-link tail and the

Mart Anton; Zheng Chen; Maarja Kruusmaa; Xiaobo Tan

2009-01-01

473

Function-Oriented Material Design of Joints for Advance Armors Under Ballistic Impact.  

National Technical Information Service (NTIS)

The objective of this research is to develop a system of software tools based on a new design methodology for the efficient composite armor structural design under ballistic impact loading conditions with a special focus on the joints design. An innovativ...

Z. Ma H. Wang B. Raju

2004-01-01

474

Composite Load Model Evaluation  

SciTech Connect

The WECC load modeling task force has dedicated its effort in the past few years to develop a composite load model that can represent behaviors of different end-user components. The modeling structure of the composite load model is recommended by the WECC load modeling task force. GE Energy has implemented this composite load model with a new function CMPLDW in its power system simulation software package, PSLF. For the last several years, Bonneville Power Administration (BPA) has taken the lead and collaborated with GE Energy to develop the new composite load model. Pacific Northwest National Laboratory (PNNL) and BPA joint force and conducted the evaluation of the CMPLDW and test its parameter settings to make sure that: • the model initializes properly, • all the parameter settings are functioning, and • the simulation results are as expected. The PNNL effort focused on testing the CMPLDW in a 4-bus system. An exhaustive testing on each parameter setting has been performed to guarantee each setting works. This report is a summary of the PNNL testing results and conclusions.

Lu, Ning; Qiao, Hong (Amy)

2007-09-30

475

The scintigraphy of sacroiliac joints  

Microsoft Academic Search

The accumulation of99mTc-methylene diphosphonate (99mTc-MDP) and99mTc-dicarboxypropane diphosphonate (99mTc-DPD) in sacroiliac (si) joints was evaluated as a function of imaging time in 22 control patients and 5 patients with sacroiliitis. The controls were injected with either99mTc-DPD or99mTc-MDP (12 and 10 patients, respectively) and the patients with sacroiliitis with both agents within 5 days. Both the anterior and posterior views of the

Tuomo Lantto

1990-01-01

476

Factory-molded cable joints  

SciTech Connect

Until recently, splicing underground transmission cable has been a delicate and time-consuming process. Now, pretested, factory-molded joints for 69-kV to 138 K-V solid-dielectric cables can be assembled quickly on site to yield connections that are as reliable as the cable itself. To produce mechanically and electrically sound splice components, however, it was necessary to extend the design criteria and manufacturing processes (including rubber compounding technology, rubber rheology, and injection molding) beyond the existing state of the art. The Electric Power Research Institute sponsored the research and development. 2 figures.

Tracy, S.; Garcia, F.

1985-06-01

477

Shock structuring due to fabrication joints in targets  

SciTech Connect

The use of copper-doped beryllium ablators on National Ignition Facility [J. A. Paisner {ital et al.}, Laser Focus World {bold 30}, 75 (1994)] targets, in place of plastic, can require the bonding together of hemispheres with a joint of differing composition. Indirect drive experiments have been conducted on the Nova laser [J. L. Emmet, W. F. Krupke, and J. B. Trenholme, Sov. J. Quantum Electron. {bold 13}, 1 (1983)], and the resulting shock structuring compared with code simulations. It is concluded that one of the available codes, the RAGE code [R. M. Baltrusaitis {ital et al.}, Phys. Fluids {bold 8}, 2471 (1996)] provides useful insight into the effect of joints. This code is then employed to obtain a physical picture of the shock front nonuniformity in terms of a secondary rarefaction and an oblique shock interacting with the main shock that propagates in the absence of the joint. A simple analysis reinforces this picture.{copyright} {ital 1999 American Institute of Physics.}

Goldman, S.R.; Caldwell, S.E.; Wilke, M.D.; Wilson, D.C.; Barnes, C.W.; Hsing, W.W.; Delamater, N.D.; Schappert, G.T.; Grove, J.W.; Lindman, E.L.; Wallace, J.M.; Weaver, R.P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Dunne, A.M.; Edwards, M.J.; Graham, P.; Thomas, B.R. [Atomic Weapons Establishment, Aldermaston, Reading, RG7 4PR (United Kingdom)

1999-08-01

478

Composites; Proceedings of the 8th International Conference on Composite Materials (ICCM\\/8), Honolulu, HI, July 15-19, 1991. Sections 1-39  

Microsoft Academic Search

The present conference on state-of-the-art composite material technologies discusses topics in the fields of design methodologies, unique applications, sandwich construction, buckling behavior, hybrid composites, fabric-reinforced composites, biomedical materials, bonded and bolted joints, composite processing, organic matrix\\/reinforcement interfaces, matrix materials, pultrusion processing, filament-winding, transfer molding, environmental effects, metal-matrix composite (MMC) processing and modeling methods, MMC interfaces, MMC strengths, and MMC fracture

S. W. Tsai; G. S. Springer

1991-01-01

479

Out of Plane Analysis for Composite Structures.  

National Technical Information Service (NTIS)

Simple two dimensional analysis techniques were developed to aid in the design of strong joints for integrally stiffened/bonded composite structures subjected to out of plane loads. It was found that most out of plane failures were due to induced stresses...

P. C. Paul C. R. Saff K. B. Sanger M. A. Mahler H. P. Kan

1990-01-01

480

DESIGN AND EVALUATION OF BONDED COMPOSITE ASSEMBLIES  

Microsoft Academic Search

This study is concerned with improving performance of composite structures through the use of adhesive bonding, particularly for marine and underwater applications. Difficulty in modeling the failure of even simple joints highlighted the need for more reliable constituent input data. The first objective was to define an experimental methodology enabling the adhesives of interest to be characterized up to failure.

J. Y. Cognard; P. Davies; L. Sohier

481

CREEP FRACTURE BEHAVIOUR OF JOINTS SOLDERED BY A NANOCOMPOSITE SOLDER, LEAD-FREE AND CONVENTIONAL TIN-LEAD SOLDERS  

Microsoft Academic Search

Creep resistance and thermal fatigue performance of soldered connections\\/joints are essential reliability concerns for microelectronic, optoelectronic and photonic packaging systems. In this study, creep fracture behaviour of lap shear joints soldered by a tin-lead based composite solder reinforced by nano-sized metallic particles and a lead-free Sn-Ag-Bi alloy solder was characterized at different homologous temperatures, with a comparison to a traditional

X. P. Zhang; Y. W. Shi; S. Shrestha; L. Dorn

482

Joint and Cooperative Inversion Strategies for Mineral Exploration  

NASA Astrophysics Data System (ADS)

Geophysical inversion for mineral exploration typically involves a single type of data sensitive to a single physical property. Combining several complimentary types of geophysical data collected over the same Earth region reduces ambiguity and can enhance inversion results. This is important whenever the Earth can not be adequately resolved by any one type of data. Combining different types of data into an inversion is important when a structural or stochastic relationship is thought to exist between the different physical property distributions. By inverting each data set individually, the recovered physical property models may be inconsistent with the geologic knowledge regarding structure or property relationships. Cooperative and joint inversion strategies can be employed to ensure consistency between the different models. A conventional cooperative inversion strategy is to invert one set of data independently and use that result to constrain a subsequent independent inversion of the second set. However, the models obtained through this simple procedure are commonly biased towards the result of the first inversion and/or towards the survey with greater sensitivity. We have developed more appropriate cooperative inversion strategies that exploit the smoothness weighting functionality of the UBC-GIF inversion codes. Another approach is to fit the data sets simultaneously in what is termed a joint inversion. Many authors have performed simultaneous inversions of data from different surveys sensitive to the same physical property. Others have jointly inverted data sets responsive to different physical properties between which there is an established analytic relationship. However, little work has focused on joint inversion of disparate data sets (from surveys responsive to different physical properties) when there is no analytic relationship available between the properties. To do so, we enforce the structural or compositional similarity between the property models. We use model-gradient dot- and cross-products to measure structural similarity (e.g. coincident boundaries of geologic bodies). We use statistical cross-correlation to measure compositional similarity, which assumes some linear relationship between the physical properties. Our joint and cooperative strategies allow inversion of disparate geophysical data sets. They ensure consistency between the recovered physical property models when stipulated by the available geologic information. These property models can then be better interpreted in concert with the geologic structural and petrophysical information.

Lelièvre, P. G.; Phillips, N. D.; Oldenburg, D. W.

2007-12-01

483

Hydrogen damage in friction welded copper joints  

Microsoft Academic Search

The occurrence of hydrogen attack in electrolytic copper and in copper deoxidized with phosphorous, during model heating in oil and in friction welded specimens was investigated. Dissimilar-metal joints, i.e. copper\\/TZM (titanium–zirconium–molybdenum based alloy) joints and copper\\/austenitic steel joints, were subjected to microstructural examinations and tensile strength tests.Microcracks near the weld surface, caused by hydrogen attack, were found to occur in

Andrzej Ambroziak

2010-01-01

484

Subtle injuries to the lisfranc joint.  

PubMed

The tarsometatarsal joint complex is an osseous and capsuloligamentous network that includes the 5 metatarsals, their articulations with the cuneiforms and cuboid, and the Lisfranc ligament, a strong interosseous attachment between the medial cuneiform and second metatarsal. A multitude of injury patterns exist involving the tarsometatarsal joint complex; a Lisfranc injury does not delineate a specific injury, but instead a spectrum of processes involving the tarsometatarsal joint complex. PMID:22050254

Rosenbaum, Andrew; Dellenbaugh, Samuel; Dipreta, John; Uhl, Richard

2011-11-01

485

Anatomy and pathophysiology of the sacroiliac joint  

Microsoft Academic Search

The sacroiliac joint as a source of chronic pain has been a subject of debate for a long period of time. This controversy\\u000a stems from the inherent anatomic location of the sacroiliac joint. Adjacent spinal structures may cause pain to be referred\\u000a to the sacroiliac joint, thus making a precise diagnosis difficult. The most reliable method to establish the diagnosis

Octavio Calvillo; Ioannis Skaribas; Joseph Turnipseed

2000-01-01

486

Joint Line Fullness and Meniscal Pathology  

PubMed Central

Background: Meniscal tears have been associated with meniscal cysts and fullness of the knee joint line on physical examination. Hypothesis: Joint line fullness is an accurate, sensitive, and specific test to detect meniscal tears. Study Design: Prospective cohort study. Methods: One hundred consecutive patients undergoing knee arthroscopy were included. All had physical examinations documenting the presence of joint line fullness, joint line tenderness, and the McMurray sign. Arthroscopy was the gold standard for tears. Accuracy, sensitivity, and specificity were calculated and correlated with type of tear. Sixty-one patients had a magnetic resonance imaging preoperatively (the gold standard for determining the presence of a cyst). Results: Meniscal tears were found in 67 patients at arthroscopy. The accuracy, sensitivity, and specificity of joint line fullness were, respectively, 73%, 70%, and 82% in detecting meniscal tears; 68%, 87%, and 30% for joint line tenderness; and 47%, 32%, and 78% for the McMurray sign. The highest positive predictive value for detecting a tear was 88% for joint line fullness, compared with 77% for joint line tenderness and 76% for the McMurray sign. However, joint line fullness did not correlate well with the presence of a cyst, with a low positive predictive value (29%). Of those patients with joint line fullness on physical examination, 89% had a horizontal cleavage component of their tear at arthroscopy. Conclusion: Joint line fullness is an accurate, sensitive, and specific test to detect meniscal tears. Clinical Relevance: The findings support the routine use of joint line fullness during physical examination along with other common tests to improve the accuracy of clinically diagnosing meniscal tears.

Couture, Jean-Francois; Al-Juhani, Wazzan; Forsythe, Michael E.; Lenczner, Eric; Marien, Robert; Burman, Mark

2012-01-01

487

Experimental architecture of joint remote state preparation  

Microsoft Academic Search

Motivated by some previous joint remote preparation schemes, we first propose some quantum circuits and photon circuits that\\u000a two senders jointly prepare an arbitrary one-qubit state to a remote receiver via GHZ state. Then, by constructing KAK decomposition\\u000a of some transformation in SO(4), one quantum circuit is constructed for jointly preparing an arbitrary two-qubit state to\\u000a the remote receiver. Furthermore,

Ming-Xing Luo; Xiu-Bo Chen; Yi-Xian Yang; Xin-Xin Niu

488

Neutron radiographic nondestructive inspection for bonded composite structures  

Microsoft Academic Search

Neutron radiography was found to be effective as a nondestructive inspection technique for detection of bondline voids\\/defects in a variety of composite structures. Radiographic data are presented from typical structures for which the neutron radiographic inspection technique offers advantages over more conventional inspection techniques. Complex composite joints such as box beam members, for example, are difficult to inspect by ultrasonic

W. E. Dance; J. B. Middlebrook

1979-01-01

489

Microrobotics using composite materials: the micromechanical flying insect thorax  

Microsoft Academic Search

The use of high performance composite materials provides a substantial performance improvement for microrobotics. Such materials have great beneflts over common MEMs materials such as better frac- ture toughness and fatigue properties than semicon- ductors, and higher stifiness to weight ratios than most metals. Composite structures yield remarkable improvements in microrobotic links and joints, as well as greater performance actuators

Robert J. Wood; Srinath Avadhanula; M. Menon; Ronald S. Fearing

2003-01-01

490

[Joint-preserving surgical options in osteoarthritis].  

PubMed

Joint-preserving surgery aims to correct the mechanical disbalances leading to the inhomogenous load distribution across joint lines, potentially leading to osteoarthritis. The possibilities of axial corrections at the knee have been known for years. A better pathophysiologic understanding of the disbalances leading to coxarthrosis has, more recently, allowed for the development of joint-preserving approaches, for instance in situations of excessive (impingement) or insufficient (dysplastic) femoro-acetabular coverage. On the opposite, in the absence of a mechanical defect, or if osteoarthritis is already present, joint-preserving surgery has little chances of success. PMID:22455151

Peter, R; Christofilopoulos, P

2012-03-14

491

Radiography in joint reconstruction with perichondrial grafts.  

PubMed

The radiographic findings in 13 joints successfully reconstructed with free perichondrial grafts from the rib are reported. Radiography was performed during a period of 13 to 40 months postoperatively. Definite cortical demarcation occurred after 8 to 11 months and had increased 11 to 16 months following surgery. In 3 cases the final examination of 2 metacarpophalangeal joints and one proximal interphalangeal joint was completed with arthrography which demonstrated that the articular surfaces appeared even although the cortical bone contours were somewhat irregular. The extent of the joint spaces largely resembled that in healthy controls. PMID:546078

Wilbrand, H; Engkvist, O

1979-01-01

492

The Joint Training System: a pillar of joint readiness and an automation challenge  

Microsoft Academic Search

The Joint Training System (JTS) (Figure 1) defines a multi-step approach to identify training requirements, plan, execute, and assess joint training events. First, and foremost, the JTS is focused on warfighting. \\

Joseph C. Barto III; Patrick D. Clark

1996-01-01

493

Age-related mobility loss is joint-specific: an analysis from 6,000 Flexitest results.  

PubMed

Although aging is commonly linked to a reduction in joint range of motion, it is unclear if all body joints behave similarly. To address this issue, the main purpose of this study was to compare age-related loss of mobility of seven body joints. A total of 6,000 participants (3,835 men and 2,165 women) aged 5 to 92 years took part in this study. The maximal passive range of motion of 20 movements was evaluated by Flexitest, and each movement was scored from 0 to 4. Composite scores were obtained for each of seven joints and for overall flexibility (Flexindex (FLX)) by adding individual movement scores. Confirming previous findings, FLX systematically decreased with aging (p?composite joint score to FLX dramatically changed. Shoulder contribution to FLX male's score went from 13.9 % at 28 years of age to only 5.2 % at 85 years of age. In general, proportionally, shoulder and trunk became less flexible, while elbow and knee mobility was preserved to a greater extent. Our findings indicated that age-related loss of mobility is rather joint-specific, which could be related to distinct routine usage patterns of the major body joints along life. PMID:23529505

Medeiros, Hugo Baptista de Oliveira; Araújo, Denise Sardinha Mendes Soares de; Araújo, Claudio Gil Soares de

2013-03-27

494

Ceramic composites for biomedical applications.  

PubMed

Ceramics have been successfully used for more than twenty years for orthopaedic prostheses, as articulating bearing surfaces against ceramic or polymer components. In both cases, ceramics are characterized by low friction coefficient and low wear rate, compared to metallic materials (stainless steels, titanium and chromium-cobalt alloys). However, their brittleness is much higher than that of metals and presently restricts the use of ceramics for hip joint balls or knee condyles. In the material science field, it is very well known that the association of two different materials can lead to new materials, often called 'composites'. Their properties can be higher than the same properties of each of the individual materials, when taken separately. Nevertheless, the word 'composites' is not universally used with the same meaning. For this reason, we will first give a few definitions in order to clearly understand what can be called 'composite' for ceramic materials. Dispersed phases increase the fracture toughness and high temperature mechanical behaviour of ceramics. In this paper, devoted to medical applications, only mechanical properties at the low (body or room) temperature are analysed. Particular attention is given to the alumina-zirconia system, because aluminium and zirconium oxides are currently accepted as biomaterials for joint prostheses. Finally, a highlight is given on the difficulties in the technological processes to obtain improved ceramic composites. PMID:10171689

Rieu, J; Goeuriot, P

1993-01-01

495

Piezoelectric film sensor for measurement of peel stresses in bonded joints  

NASA Astrophysics Data System (ADS)

Adhesively bonded composite patches employed for repairing fatigue cracks in metallic airframe structural components often fail under peel stress generated in the structure. The application of piezoelectric stress sensors embedded within the bonded joint for direct measurement of the peel stresses is reported here. Polyvinylidine fluoride (PVDF) film of about 28 micron thickness coated with nickel copper is employed to construct hin sensors embedded between the composite patch and the metallic surface of the crotch joint specimen. PVDF sensor with varying sizes were constructed and calibrated using polycarbonate test specimens subjected to uniaxial tension and compression. The sensors were then embedded between the composite patch and the metallic surface of the crotch specimen to monitor the peel stresses in the adhesive. The measurements are compare with stresses in the adhesive. The measurements are compared with stresses predicted by finite element modeling.

Shankar, Krishnakumar; Tahtali, Murat; Chester, Richard; Torr, Glen

2001-06-01

496

Nano-material aspects of shock absorption in bone joints.  

PubMed

This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones. PMID:21625375

Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

2010-11-03

497

Designing bonded joints by means of the JointCalc software  

Microsoft Academic Search

This paper describes the theoretical framework, the experimental background and the software implementation of the computer package JointCalc for the strength analysis and design of adhesively bonded joints. Developed by Henkel AG in collaboration with three Italian Universities, JointCalc was designed to be accessible to non-experts, intuitive for occasional users and also general enough to include most of the joint

E. Dragoni; L. Goglio; F. Kleiner

2010-01-01

498

Temporomandibular joint dysfunction syndrome: a close association with systemic joint laxity (the hypermobile joint syndrome)  

PubMed

Sixty-two patients admitted for elective reconstructive surgery of the temporomandibular joint (TMJ) and eight seen as outpatients with a chief complaint of TMJ dysfunction during the same time interval were evaluated for possible etiologic factors contributing to the disease. All hospitalized patients had severe, end-stage degenerative changes within the TMJ, whereas outpatients had less severe disease and did not require surgery. TMJ dysfunction in some patients was said to be a result of established causes including bruxism, malocclusion, and trauma. No patient in this series had evidence of a systemic inflammatory polyarthritis. Of the 70 patients, 38 (54%) met criteria, based on those of Carter and Wilkinson, as modified by Beighton et al., sufficient to warrant a diagnosis of the hypermobile joint syndrome. Five patients had classic Ehlers-Danlos syndrome and therefore were not patients with "benign hypermobility," and an additional two cases were described as "marfanoid" and as possible Ehlers-Danlos syndrome, respectively. Radiographs showed TMJ hyperextensibility in four hypermobile patients. Long-term surgical outcome was identical in the hypermobile and nonhypermobile groups. The incidence of hypermobility in this series is strikingly higher than the expected incidence in an otherwise population. Magnetic resonance images of the TMJs on separate groups of asymptomatic normal and hypermobile women identified excessive anterior movement in the hypermobile group, together with abnormal anterior disk position in some. We hypothesize that hypermobility within the TMJ may cause accelerated disk destruction and degenerative disease. PMID:1745506

Buckingham, R B; Braun, T; Harinstein, D A; Oral, K; Bauman, D; Bartynski, W; Killian, P J; Bidula, L P

1991-11-01

499

Joint Attention in Autism: Teaching Smiling Coordinated with Gaze to Respond to Joint Attention Bids  

ERIC Educational Resources Information Center

Children with autism demonstrate early deficits in joint attention and expressions of affect. Interventions to teach joint attention have addressed gaze behavior, gestures, and vocalizations, but have not specifically taught an expression of positive affect such as smiling that tends to occur during joint attention interactions. Intervention was…

Krstovska-Guerrero, Ivana; Jones, Emily A.

2013-01-01

500

Damage Parameters of Adhesive Joints with General Triaxiality, Part 2: Scarf Joint Analysis  

Microsoft Academic Search

Based on the finite element results presented in part 1 of this paper, scarf joint was chosen for further experimental investigation in order to investigate triaxiality as a function of bondline angle. At laboratory scale, scarf joints can be manufactured relatively easy due to their simple geometry. In part 2 of this paper, scarf joints as well as additional jig\\/fixture

M. M. Abdel Wahab; I. Hilmy; I. A. Ashcroft; A. D. Crocombe

2011-01-01