STS-43 Pilot Baker eats a sandwich on OV-104's forward flight deck

NASA Technical Reports Server (NTRS)

1991-01-01

STS-43 Pilot Michael A. Baker, seated at the forward flight deck pilots station controls, eats a freefloating peanut butter and jelly sandwich while holding a carrot. Surrounding Baker on Atlantis', Orbiter Vehicle (OV) 104's, flight deck are procedural checklists, control panels, and windows. A lemonade drink bag is velcroed to overhead panel O9.

Glulam timber deck bridges : final report.

DOT National Transportation Integrated Search

1979-01-01

This report discusses the construction and initial condition of the Virginia Department of Highways and Transportation's first three bridges built with glulam panels on steel stringers. The data show that superstructures with glulam deck panels are m...

78 FR 79289 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-30

... leakage into the main deck cargo wire integration unit (WIU). The water flowed from the main deck floor... deck cargo wire integration unit (WIU). The water flowed from the main deck floor panels, through...

DETAIL VIEW OF SINGLE PANEL POINTS TAKEN FROM BRIDGE DECK, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW OF SINGLE PANEL POINTS TAKEN FROM BRIDGE DECK, SHOWING CONNECTION BETWEEN VERTICAL AND UPPER CHORD MEMBER - White Bowstring Arch Truss Bridge, Spanning Yellow Creek at Cemetery Drive (Riverside Drive), Poland, Mahoning County, OH

Composite action in a steel girder span with precast deck panels : the I-81 bridge over the New River in Radford, Virginia.

DOT National Transportation Integrated Search

2003-01-01

Two parallel bridges carry I-81 north and south over the New River in southwest Virginia, near the city of Radford. The bridges are identical in design and have been in place since 1985. In recent years, a number of maintenance issues have been repor...

Spalling solution of precast-prestressed bridge deck panels.

DOT National Transportation Integrated Search

2010-10-01

This research has examined spalling of several partial-depth precast prestressed concrete (PPC) bridge decks. It was recently obser : that some bridges with this panel system in the MoDOT inventory have experienced rusting of embedded steel reinforce...

Polyurethane foam infill for fiber-reinforced polymer (FRP) bridge deck panels.

DOT National Transportation Integrated Search

2014-05-01

The objective of the proposed research is to develop, test, and evaluate fiber-reinforced, polyurethane foams to replace the costly : honeycomb construction currently used to manufacture FRP bridge deck panels. The effort will focus on developing an ...

DETAIL OF VERTICAL AT PANEL OVER PIER C, SHOWING DECK, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF VERTICAL AT PANEL OVER PIER C, SHOWING DECK, GUARDRAIL, VERTICAL AND UPPER CHORD, VIEW TO NORTHEAST. - Blue Water Bridge, Spanning St. Clair River at I-69, I-94, & Canadian Route 402, Port Huron, St. Clair County, MI

Design guide for precast UHPC waffle deck panel system, including connections.

DOT National Transportation Integrated Search

2013-06-01

As a part of an innovation project funded by the Federal Highway Administration (FHWA) Highways for LIFE program, a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementa...

Analytical and experimental evaluation of an aluminum bridge deck panel. Part 2, failure analysis.

DOT National Transportation Integrated Search

1999-01-01

Aluminum bridge decks may prove to be an alternative to concrete decks for improving the performance of structural bridge systems. Combining excellent corrosion resistance with extremely low density, aluminum decks can prolong surface life, facilitat...

Evaluation of a bridge deck with CFRP prestressed panels under fatigue load cycles

DOT National Transportation Integrated Search

2003-09-01

This report summarizes a study conducted under an IBRC (Innovative Bridge Research and Construction) project sponsored by the FHWA. In this project, a bridge deck with CFRP (carbon fiber reinforced polymeric) prestressed panels and cast-in-place topp...

Experimental and analytical investigation of full-depth precast deck panels on prestressed I-girders.

DOT National Transportation Integrated Search

2008-01-01

A bridge with precast bridge deck panels was built at the Virginia Tech Structures Laboratory to examine constructibility issues, creep and shrinkage behavior, and strength and fatigue performance of transverse joints, different types of shear connec...

Health monitoring of precast bridge deck panels reinforced with glass fiber reinforced polymer (GFRP) bars.

DOT National Transportation Integrated Search

2012-03-01

The present research project investigates monitoring concrete precast panels for bridge decks that are reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. Due to the lack of long term research on concrete members reinforced with GFRP bars, lo...

Material investigation of the full-depth, precast concrete deck panels of the old Woodrow Wilson Bridge.

DOT National Transportation Integrated Search

2007-01-01

The Woodrow Wilson Memorial Bridge crossing the Potomac River near Washington, D.C., was replaced after more than 45 years of service. Researchers examined the full-depth, precast lightweight concrete deck panels that were installed on this structure...

STS-26 Pilot Covey, wearing sleep mask, rests on aft flight deck

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Pilot Richard O. Covey, wearing sleep mask (blindfold) and a headset, props his feet under the pilots seat and rests his head and back on the aft flight deck onorbit station panels while he sleeps. At Covey's right are the mission station control panels.

Pilot Fullerton sleeps on aft flight deck

NASA Image and Video Library

1982-03-30

STS003-22-113 (24 March 1982) --- Astronaut Gordon Fullerton, STS-3 pilot, wearing communication kit assembly mini-headset (HDST), sleeps on aft flight deck resting his back against the floor and his feet against commander's ejection seat (S1) back. On-orbit station control panel A8 and payload station panel L15 appear above Fullerton. Special clips for holding notebooks open and beverage containers are velcroed on various panels. Photo credit: NASA

Macromolecular Networks Containing Fluorinated Cyclic Moieties

DTIC Science & Technology

2015-12-12

Approved for public release.  Distribution is unlimited.   Cyanate Esters Around the Solar System 4 Images:  courtesy  NASA  (public release) • The...science decks on the Mars Phoenix lander are made from M55J/cyanate ester composites • The solar panel supports on the MESSENGER space probe use cyanate...thermonuclear fusion reactor Fusion reactor, photo  courtesy of Gerritse ((Wikimedia Commons) • Unique cyanate ester composites have been designed by NASA

Ultra-high performance fiber-reinforced concrete (UHPFRC) for infrastructure rehabilitation Volume II : behavior of ultra-high strength concrete bridge deck panels compared to conventional stay-in-place deck panels

DOT National Transportation Integrated Search

2017-08-01

The remarkable features of ultra-high performance concrete (UHPC) have been reported. Its application in bridge construction has been an active research area in recent years, attributed to its higher compressive strength, higher ductility and reduced...

STS-26 Pilot Covey, wearing sleep mask, rests on aft flight deck

NASA Image and Video Library

1988-10-03

STS026-09-021 (3 Oct 1988) --- Astronaut Richard O. Covey, STS-26 pilot, wearing sleep mask (blindfold) and a headset, props his feet under the pilots seat and rests his head and back on the aft flight deck on orbit station panels while he sleeps. At Covey's right are the mission station control panels.

Commander Brand and Pilot Overmyer operate controls on forward flight deck

NASA Technical Reports Server (NTRS)

1982-01-01

On forward flight deck, Commander Brand and Pilot Overmyer operate controls from commanders and pilots seats. Overall view taken from the aft flight deck looking forward shows Overmyer pointing to data on Panel 7 (F7) CRT 1 screen.

Commander Brand sleeps on aft flight deck

NASA Technical Reports Server (NTRS)

1982-01-01

Commander Brand, with hands folded in front of his chest, sleeps on aft flight deck. Brand's head is just above aft flight deck floor with his back to onorbit station panels. The back and feet of a second crewmember appear next to Brand.

Analytical and experimental evaluation of an aluminum bridge deck panel. Part 1, Service load performance.

DOT National Transportation Integrated Search

1999-01-01

Deck deterioration is responsible for the majority of deficient bridge ratings in the United States (Sotiropoulos & GangaRao, 1993). Subject to dynamic loading, cyclic loading, and occasional overloading, bridge decks are the most severely stressed e...

Structural Assessment of Externally Strengthened Bridge Deck Panels

NASA Astrophysics Data System (ADS)

Sim, Jongsung; Oh, Hongseob; Meyer, Christian

2006-03-01

Deteriorated concrete bridge decks are strengthened with external bonding technique using either steel plate or various FRPs to enhance the decreased load carrying capacity and serviceability. But the failure characteristics of bridge decks strengthened with various materials can be changed according to mechanical properties of strengthening materials or strengthening scheme as well as the strengthening amount. In this paper, strengthening effect of deck strengthened with carbon fiber sheets, glass fiber sheets or steel plates is compared. And the theoretical load carrying capacity are evaluated using yield line theory and punching shear model properly modified for the strengthened RC member. The panels strengthened with sheet type FRP materials failed more often in a ductile mode, indicating that the failure developed after the rebar yielded.

T-section glulam timber bridge modules : modeling and performance

Treesearch

Paul A. Morgan; Steven E. Taylor; Michael A. Ritter; John M. Franklin

1999-01-01

This paper describes the design, modeling, and testing of two portable timber bridges, each consisting of two noninterconnected longitudinal glued-laminated timber (glulam) deck panels 1.8 m (6 ft) wide. One bridge is 12.2 m (40 ft) long while the other bridge is 10.7 m (35 ft) long. The deck panels are fabricated in a unique double-tee cross section. The bridges...

STS-43 Pilot Baker eats a sandwich on OV-104's forward flight deck

NASA Image and Video Library

1991-08-11

STS043-02-020 (2-11 Aug. 1991) --- Astronaut Michael A. Baker, STS-43 pilot, seated at the forward flight deck pilot station controls of the Space Shuttle Atlantis, eats a free-floating peanut butter and jelly sandwich while holding a carrot. Surrounding Baker are procedural checklists, control panels, and windows. A lemonade drink bag is velcroed to overhead panel.

The effects of temperature on fiber composite bridge decks.

DOT National Transportation Integrated Search

2009-01-01

In this study the fiber composite bridge decks were subjected to thermal gradients to obtain the temperature difference between the top and bottom surface of the decks and to determine the thermal properties of the deck. The fiber composite bridge de...

Structural health monitoring of Lindquist bridge

NASA Astrophysics Data System (ADS)

Sargent, D. D.; Murison, E. R.; Bakht, B.; Mufti, A. A.

2007-04-01

Many forestry bridges in Canada are typically single-lane, single span structures with two steel plate girders and a deck comprising of precast reinforced concrete panels. The concept of arching in deck slabs was utilized in the steel-free precast panels used in the Lindquist Bridge in British Columbia, Canada. The panels were completely devoid of tensile reinforcement and transverse confinement to the panels was provided by external steel straps. After the bridge was constructed in 1998, electrical strain gauges were installed on the girders and straps. Static and dynamic load tests were performed. The cracks on the top and bottom of the deck were mapped in 1999 and 2003. In 2006, a load test and crack mapping were performed on the bridge. The strain readings in the straps were compared with the data obtained 8 years prior. After analysis of the strain gauge readings, conclusions were drawn on the performance of the bridge. The cracks were formed to accommodate arching action and it was concluded that the bridge is still performing as it was designed.

Pilot Fullerton points Hasselblad camera out forward flight deck window W6

NASA Technical Reports Server (NTRS)

1982-01-01

Pilot Fullerton, wearing communications kit assembly (ASSY) mini headset (HDST), points Hasselblad camera out forward flight deck pilots station window W6. Forward flight deck control panels F4, F8, and R1, flight mirror assy, Volume R5 Kit, and pilots ejection seat (S2) headrest appear in view.

Hydrolytic Network Structure Degradation in Multi-Component Polycyanurate Networks

DTIC Science & Technology

2016-07-28

Approved for Public Release; Distribution Unlimited. PA# 16335 UNCLASSIFIED Cyanate Esters Around the Solar System Images:  courtesy  NASA  (public...release) • The science decks on the Mars Phoenix lander are made from M55J/cyanate ester composites • The solar panel supports on the MESSENGER space...designed by NASA for use as instrument holding structures aboard the James Webb Space Telescope Photo courtesy of  NASA 5Distribution A: Approved for

Flight deck automation: Promises and realities

NASA Technical Reports Server (NTRS)

Norman, Susan D. (Editor); Orlady, Harry W. (Editor)

1989-01-01

Issues of flight deck automation are multifaceted and complex. The rapid introduction of advanced computer-based technology onto the flight deck of transport category aircraft has had considerable impact both on aircraft operations and on the flight crew. As part of NASA's responsibility to facilitate an active exchange of ideas and information among members of the aviation community, a NASA/FAA/Industry workshop devoted to flight deck automation, organized by the Aerospace Human Factors Research Division of NASA Ames Research Center. Participants were invited from industry and from government organizations responsible for design, certification, operation, and accident investigation of transport category, automated aircraft. The goal of the workshop was to clarify the implications of automation, both positive and negative. Workshop panels and working groups identified issues regarding the design, training, and procedural aspects of flight deck automation, as well as the crew's ability to interact and perform effectively with the new technology. The proceedings include the invited papers and the panel and working group reports, as well as the summary and conclusions of the conference.

Self-stressed sandwich bridge decks.

DOT National Transportation Integrated Search

1971-01-01

Proposed is an entirely new type of bridge deck, consisting of an unreinforced lightweight concrete slab made of expanding cement sandwiched between two thin plates of steel. The expanding core serves to prestress the panel. Laboratory tests were con...

Fiber reinforced polymer bridge decks.

DOT National Transportation Integrated Search

2011-01-01

The overarching goal of this study was to perform a comprehensive evaluation of various issues related to the strength and serviceability : of the FRP deck panels that are available in the industry. Specific objectives were to establish critical limi...

Second generation precast deck panel (NUDECK) system.

DOT National Transportation Integrated Search

2010-12-01

"The majority of todays bridge decks are built using cast-in-place concrete construction. This is due to the perceived : low initial cost and constructor familiarity with the system. This research report describes the design, details, and : constr...

Second generation precast deck panel (NUDECK) system.

DOT National Transportation Integrated Search

2010-12-01

The majority of today's bridge decks are built using cast-in-place concrete construction. This is due to the perceived : low initial cost and constructor familiarity with the system. This research report describes the design, details, and : construct...

Fatigue reliability of deck structures subjected to correlated crack growth

NASA Astrophysics Data System (ADS)

Feng, G. Q.; Garbatov, Y.; Guedes Soares, C.

2013-12-01

The objective of this work is to analyse fatigue reliability of deck structures subjected to correlated crack growth. The stress intensity factors of the correlated cracks are obtained by finite element analysis and based on which the geometry correction functions are derived. The Monte Carlo simulations are applied to predict the statistical descriptors of correlated cracks based on the Paris-Erdogan equation. A probabilistic model of crack growth as a function of time is used to analyse the fatigue reliability of deck structures accounting for the crack propagation correlation. A deck structure is modelled as a series system of stiffened panels, where a stiffened panel is regarded as a parallel system composed of plates and are longitudinal. It has been proven that the method developed here can be conveniently applied to perform the fatigue reliability assessment of structures subjected to correlated crack growth.

Abrasion-resistant concrete mix designs for precast bridge deck panels.

DOT National Transportation Integrated Search

2010-08-01

The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) re...

PCP cracking and bridge deck reinforcement : an interim report.

DOT National Transportation Integrated Search

2010-10-28

TxDOT Project 0-6348 Controlling Cracking in Prestressed Concrete Panels and Optimizing Bridge Deck : Reinforcing Steel started on September 1, 2008 and is scheduled to end on August 31, 2012. The project is : proceeding on schedule. This repor...

Attic Retrofits Using Nail-Base Insulated Panels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mallay, David; Kochkin, Vladimir

This project developed and demonstrated a roof/attic energy retrofit solution using nail-base insulated panels for existing homes where traditional attic insulation approaches are not effective or feasible. Nail-base insulated panels (retrofit panels) consist of rigid foam insulation laminated to one face of a wood structural panel. The prefabricated panels are installed above the existing roof deck during a reroofing effort.

Evaluating the constructability of NUDECK precast concrete deck panels for Kearney Bypass Project.

DOT National Transportation Integrated Search

2015-02-01

The first generation of precast concrete deck system, NUDECK, was implemented on the Skyline Bridge, : Omaha, NE in 2004. The second generation of NUDECK system was developed to further simplify the : system and improve its constructability and durab...

Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck.

DOT National Transportation Integrated Search

2012-01-31

Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all : the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of : the bridge ...

Rational load rating of deck-girder bridges with girder end shear cracks in reverse orientation : technical summary.

DOT National Transportation Integrated Search

2017-04-01

A user interface creates a grillage model of an existing bridge and places various rating trucks on the : bridge. Equivalent flexibility analysis distributes truck live loads within deck panels to surrounding : girders and diaphragms. Stiffness matri...

Aft flight deck documentation with freefloating headset interface unit (HIU)

NASA Image and Video Library

1983-09-05

STS008-18-479 (5 Sept 1983) --- Aft flight deck documentation includes on orbit station with control panel A2, aft viewing window W9, and communications kit assembly (ASSY) headset (HDST) interface unit (HIU) and cable free floating in front of it.

12. Credit JTL: Detail view, two panels at north end ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Credit JTL: Detail view, two panels at north end of western truss from bridge deck, showing end panel details; cast iron end post is missing - Reading-Halls Station Bridge, U.S. Route 220, spanning railroad near Halls Station, Muncy, Lycoming County, PA

General view of the mid deck of the Orbiter Discovery ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the mid deck of the Orbiter Discovery during pre-launch preparations. Note the payload and mission specialists seats. The seats are removed packed and stowed during on-orbit activities. Also not the black panels in the right of the image, they are protective panels used for preparation of the orbiter and astronaut ingress while the orbiter is in its vertical launch position. This image was taken at Kenney Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Pilot Fullerton in ejection escape suit (EES) on aft flight deck

NASA Image and Video Library

1982-03-30

STS003-31-290 (30 March 1982) --- Astronaut Gordon Fullerton, STS-3 pilot, wearing communications kit assembly (ASSY) mini-headset (HDST) and ejection escape suit (EES), holds flexible hose attached to his EES vent hose fitting and second hose for commander's EES while behind pilots ejection seat (S2) seat back on the aft flight deck. Forward flight deck control panels are visible in the background. Photo credit: NASA

Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck : [appendices].

DOT National Transportation Integrated Search

2012-01-31

Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of the bridge need...

Deployment of Lightweight Shock Mitigating Boat Manufacturing Innovation

DTIC Science & Technology

2012-12-21

70 LC1- AMI- Z Displacement- Deck ~ HHH ~EEE~~~~~~~ ~~~~!!!!!!~5...between bulkheads Applied to two panels and included stringer 69 LC1- AMI-10 psi Pressure Load 70 LC1- AMI- Z Displacement- Deck ~ HHH ~EEE

7. View showing placement of timber deck placement on chord ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View showing placement of timber deck placement on chord and built up construction of top chord and continuous construction through top panel points, eye bar construction on bottom chord - Bridge No. 2.4, Spanning Boiling Fork Creek at Railroad Milepost JC-2.4, Decherd, Franklin County, TN

General view of the flight deck of the orbiter Discovery ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the flight deck of the orbiter Discovery looking forward and overhead at the overhead instrumentation and control panels. This view was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Laser welded steel sandwich panel bridge deck development : finite element analysis and stake weld strength tests.

DOT National Transportation Integrated Search

2009-09-01

This report summarizes the analysis of laser welded steel sandwich panels for use in bridge structures and : static testing of laser stake welded lap shear coupons. Steel sandwich panels consist of two face sheets : connected by a relatively low-dens...

Considerations in recycling of wood-plastic composites

Treesearch

J.E. Winandy; N.M. Stark; C.M. Clemons

2004-01-01

Wood-plastic composite decking has made major advances in material performance, processing and user acceptance. The growth of wood-plastic composite decking in North America has grown from less than 1 % in mid- 0's to over 10% today with growth projected by several studies to reach +20% before the end of this decade (2010). Preservative-treated wood decking...

General view of he forward wall of the mid deck ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of he forward wall of the mid deck of the Orbiter Discovery. In this view a majority of wall panels have been removed to reveal the avionics bays in the interstitial space between the mid deck forward wall and the forward bulkhead of the pressurized crew compartment. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Investigation of early timber–concrete composite bridges in the United States

Treesearch

James P. Wacker; Alfredo Dias; Travis K. Hosteng

2017-01-01

The use of timber–concrete composite (TCC) bridges in the United States dates back to circa 1925. Two different TCC systems were constructed during this early period. The first system included a longitudinal nail-laminated deck composite with a concrete deck top layer. The second system included sawn timber stringers supporting a concrete deck top layer. Records...

10. VIEW LOOKING FORWARD ON STARBOARD SIDE OF MAIN DECK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. VIEW LOOKING FORWARD ON STARBOARD SIDE OF MAIN DECK FROM POINT NEAR ENGINE CONTROL PANEL. DECKHOUSES, FROM LEFT TO RIGHT (STERN TO BOW), ARE AFT COMPANIONWAY, PILOTS' CABIN SKYLIGHT, ENGINE ROOM SKYLIGHT, AND GALLEY SKYLIGHT/COMPANIONWAY - Pilot Schooner "Alabama", Moored in harbor at Vineyard Haven, Vineyard Haven, Dukes County, MA

STS-44 Atlantis, OV-104, crewmembers participate in JSC FB-SMS training

NASA Technical Reports Server (NTRS)

1991-01-01

STS-44 Atlantis, Orbiter Vehicle (OV) 104, Commander Frederick D. Gregory and Pilot Terence T. Henricks are stationed at their appointed positions on the forward flight deck of the Fixed Base (FB) Shuttle Mission Simulator (SMS) in JSC's Mission Simulation and Training Facility Bldg 5. Gregory (left) in the commanders seat and Henricks (right) in the pilots seat look back toward aft flight deck and the photographer. Seat backs appear in the foreground and forward flight deck control panels in the background.

6. DETAIL VIEW OF SINGLE PANEL POINTS TAKEN FROM BRIDGE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. DETAIL VIEW OF SINGLE PANEL POINTS TAKEN FROM BRIDGE DECK, SHOWING CONNECTION BETWEEN VERTICAL AND UPPER CHORD MEMBER. - White Bowstring Arch Truss Bridge, Spanning Yellow Creek at Cemetery Drive (Riverside Drive), Poland, Mahoning County, OH

Interior view of the Flight Deck looking forward, the Commander's ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior view of the Flight Deck looking forward, the Commander's seat and controls are on the left and the pilot's seat and controls are on the right of the view. Note that the flight deck windows have protective covers over them in this view. This images can be digitally stitched with image HAER No. TX-116-A-20 to expand the view to include the overhead control panels of the flight deck. This view was taken in the Orbiter Processing Facility at the Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Composite Action in Prestressed NU I-Girder Bridge Deck Systems Constructed with Bond Breakers to Facilitate Deck Removal

DOT National Transportation Integrated Search

2017-11-01

Results are reported from tests of small-scale push-off and large-scale composite NU I-girder specimens conducted to establish an interface connection detail that (1) Facilitates in-situ removal of the bridge deck without damaging prestressed girders...

29 CFR 1926.754 - Structural steel assembly.

Code of Federal Regulations, 2013 CFR

2013-07-01

... connectors on composite floors, roofs and bridge decks. When shear connectors are used in construction of composite floors, roofs and bridge decks, employees shall lay out and install the shear connectors after the... requirements of paragraph (e)(3)(i) of this section. (4) Decking gaps around columns. Wire mesh, exterior...

29 CFR 1926.754 - Structural steel assembly.

Code of Federal Regulations, 2012 CFR

2012-07-01

... connectors on composite floors, roofs and bridge decks. When shear connectors are used in construction of composite floors, roofs and bridge decks, employees shall lay out and install the shear connectors after the... requirements of paragraph (e)(3)(i) of this section. (4) Decking gaps around columns. Wire mesh, exterior...

29 CFR 1926.754 - Structural steel assembly.

Code of Federal Regulations, 2014 CFR

2014-07-01

... connectors on composite floors, roofs and bridge decks. When shear connectors are used in construction of composite floors, roofs and bridge decks, employees shall lay out and install the shear connectors after the... requirements of paragraph (e)(3)(i) of this section. (4) Decking gaps around columns. Wire mesh, exterior...

Composite Action in Prestressed NU I-Girder Bridge Deck Systems Constructed with Bond Breakers to Facilitate Deck Removal : Technical Summary

DOT National Transportation Integrated Search

2017-11-01

Results are reported from tests of small-scale push-off and large-scale composite NU I-girder specimens conducted to establish an interface connection detail that (1) Facilitates in-situ removal of the bridge deck without damaging prestressed girders...

Plate & tube bridge deck evaluation in the deck test bed of the Troutville, Virginia, weigh station.

DOT National Transportation Integrated Search

2004-01-01

This report addresses the laboratory and field performance of multi-cellular fiber-reinforced polymer (FRP) composite bridge deck systems. We focus specifically on FRP decks produced from adhesively bonded pultrusions where the core of the deck posse...

A field installation using prestressed panel subdecks.

DOT National Transportation Integrated Search

1978-01-01

This final report is a supplement to an earlier report that covered the installation of the first precast, prestressed panel subdecks installed on a bridge in Virginia. The report discusses the inspection of the decks one year after they were complet...

STS-30 Commander Walker on forward flight deck

NASA Technical Reports Server (NTRS)

1989-01-01

On Atlantis', Orbiter Vehicle (OV) 104's, forward flight deck between commanders and pilots seats, STS-30 Commander David M. Walker smiles while having his picture taken. Walker, wearing a mission polo shirt and light blue flight coverall pants, holds onto the commanders seat back. Forward flight control panels are visible above Walker's head and behind him.

30. VIEW LOOKING FORWARD ON STARBOARD SIDE OF MAIN DECK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. VIEW LOOKING FORWARD ON STARBOARD SIDE OF MAIN DECK FROM ALONGSIDE ENGINE CONTROL PANEL. CONFIGURATION OF SKYLIGHTS AND COMPANIONWAY DIFFERENT FROM WHAT WAS FOUND BY HAER IN 1986. Original 4-3/4'x6-3/4' photograph taken c. 1930? - Pilot Schooner "Alabama", Moored in harbor at Vineyard Haven, Vineyard Haven, Dukes County, MA

Recommendations for the use of precast deck panels at expansion joints

DOT National Transportation Integrated Search

2008-11-01

Prestressed concrete panels have been used by the bridge construction industry in the state of Texas for many : years to increase construction speed and improve safety and economy. At expansion joints, cast-in-place concrete : is used and requires te...

Development of a precast bridge deck overhang system for the rock creek bridge.

DOT National Transportation Integrated Search

2008-12-01

Precast, prestressed panels are commonly used at interior beams for bridges in Texas. The use of these : panels provides ease of construction, sufficient capacity, and good economy for the construction of : bridges in Texas. Current practice for the ...

Pilot Fullerton reviews checklist on Aft Flight Deck Onorbit Station

NASA Technical Reports Server (NTRS)

1982-01-01

Pilot Fullerton, wearing communication kit assembly (assy) mini headset, reviews checklist and looks at remote manipulator system (RMS) closed circuit television (CCTV) views displayed on CCTV monitors at Aft Flight Deck Onorbit Station. Taken from the aft flight deck starboard side, Fullerton is seen in front of Panels A7 and A8 with remote manipulator syste (RMS) translation hand control (THC) and RMS rotation hand control (RHC) in the foreground and surrounded by University of Michigan (U of M) GO BLUE and United States Air Force - A Great Way of Life Decals.

Closeup view of the Pilot's Seat on the Flight Deck ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the Pilot's Seat on the Flight Deck of the Orbiter Discovery. It appears the Orbiter is in the roll out / launch pad configuration. A protective cover is over the Rotational Hand Controller to protect it during the pilot's ingress. Control panels R1 and R2 are prominent in this view. Panel R1 has switches for control and maintenance of on-board cryogenics for the fuel cells among other functions and panel R2 has switches and controls for the Auxiliary Power Units, ET umbilical doors as well as other operational controls. Note the portable fire extinguisher in the lower right corner of the image. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Live load distribution on longitudinal glued-laminated timber deck bridges : final report : conclusions and recommendations

Treesearch

Fouad Fanous; Jeremy May; Terry Wipf; Michael Ritter

2010-01-01

Over the past few years the United States Department of Agriculture (USDA), Forest Products Laboratory (FPL), and the Federal Highway Administration (FHWA) have supported several research programs. This paper is a result of a study sponsored by FPL, with the objective of determining how truckloads are distributed to the deck panels of a longitudinal glued-laminated...

14. NBS REMOTE MANIPULATOR SIMULATOR (RMS) CONTROL ROOM. THE RMS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. NBS REMOTE MANIPULATOR SIMULATOR (RMS) CONTROL ROOM. THE RMS CONTROL PANEL IS IDENTICAL TO THE SHUTTLE ORBITER AFT FLIGHT DECK WITH ALL RMS SWITCHES AND CONTROL KNOBS FOR INVOKING ANY POSSIBLE FLIGHT OPERATIONAL MODE. THIS INCLUDES ALL COMPUTER AIDED OPERATIONAL MODES, AS WELL AS FULL MANUAL MODE. THE MONITORS IN THE AFT FLIGHT DECK WINDOWS AND THE GLASSES THE OPERATOR WEARS PROVIDE A 3-D VIDEO PICTURE TO AID THE OPERATOR WITH DEPTH PERCEPTION WHILE OPERATING THE ARM. THIS IS REQUIRED BECAUSE THE RMS OPERATOR CANNOT VIEW RMS MOVEMENTS IN THE WATER WHILE AT THE CONTROL PANEL. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

STS-39 MS Veach monitors AFP-675 panel on OV-103's aft flight deck

NASA Image and Video Library

1991-05-06

STS039-09-036 (28 April-6 May 1991) --- Astronaut Charles L. (Lacy) Veach monitors experiment data on the aft flight deck of the Earth-orbiting Discovery. The photograph was taken with a 35mm camera. Veach and six other NASA astronauts spent over eight days in space busily collecting data for this mission, dedicated to the Department of Defense.

STS-79 crew on flight deck after launch

NASA Image and Video Library

1996-10-29

STS079-348-004 (16 Sept. 1996) --- Soon after the space shuttle Atlantis completed its rocket mode ascent to Earth-orbit, astronaut Terrence W. Wilcutt, pilot, begins to ready the Orbiter for ten days of orbiting Earth by activating switches on the flight deck's right overhead panel. Though the launch was a nocturnal one, the crew experienced its first sunrise just after Atlantis achieved its orbital posture.

Closeup view of the aft flight deck of the Orbiter ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the aft flight deck of the Orbiter Discovery looking at the aft center control panels A6, A7, A8, A12, A13, A14, A16 and A17. This View was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

STS-27 crew poses for inflight portrait on forward flight deck with football

NASA Technical Reports Server (NTRS)

1988-01-01

With WILSON NFL football freefloating in front of them, STS-27 astronauts pose on Atlantis', Orbiter Vehicle (OV) 104's, forward flight deck for inflight crew portrait. Crewmembers, wearing blue mission t-shirts, are (left to right) Commander Robert L. Gibson, Mission Specialist (MS) Richard M. Mullane, MS Jerry L. Ross, MS William M. Shepherd, and Pilot Guy S. Gardner. Forward flight deck overhead control panels are visible above crewmembers, commanders and pilots seats in front of them, and forward windows behind them. An auto-set 35mm camera mounted on the aft flight deck was used to take this photo. The football was later presented to the National Football League (NFL) at halftime of the Super Bowl in Miami.

Endeavour, OV-105, forward flight deck controls during Rockwell manufacture

NASA Technical Reports Server (NTRS)

1991-01-01

Endeavour, Orbiter Vehicle (OV) 105, forward flight deck controls are documented during manufacture, assembly, and checkout at North American Rockwell facilities Building 150, Palmdale, California. Overall view looks from aft flight deck forward showing displays and controls with panel F7 CRT screens lit and window shades in place on W2, W3, W4, W5. OV-105 is undergoing final touches prior to rollout and a scheduled flight for STS-49. View was included as part of Rockwell International (RI) Submittal No. 40 (STS 87-0342-40) with alternate number A901207 R-16/NAS9-17800.

Detail view of the interior of the flight deck looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail view of the interior of the flight deck looking forward showing the overhead control panels. Note that the flight deck windows have protective covers over them in this view. This images can be digitally stitched with image HAER No. TX-116-A-19 to expand the view to include the Commander and Pilot positions during ascent and reentry and landing. This view was taken in the Orbiter Processing Facility at the Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Experimental and finite element study of ultimate strength of continuous composite concrete slabs with steel decking

NASA Astrophysics Data System (ADS)

Gholamhoseini, Alireza

2018-03-01

Composite one-way concrete slabs with profiled steel decking as permanent formwork are commonly used in the construction industry. The steel decking supports the wet concrete of a cast in situ reinforced or post-tensioned concrete slab and, after the concrete sets, acts as external reinforcement. In this type of slab, longitudinal shear failure between the concrete and the steel decking is the most common type of failure at the ultimate load stage. Design codes require the experimental evaluation of the ultimate load capacity and longitudinal shear strength of each type of steel decking using full-scale tests on simple-span slabs. There is also no procedure in current design codes to evaluate the ultimate load capacity and longitudinal shear strength of continuous composite slabs and this is often assessed experimentally by full-scale tests. This paper presents the results of three full-scale tests up to failure on continuous composite concrete slabs cast with trapezoidal steel decking profile (KF70) that is widely used in Australia. Slab specimens were tested in four-point bending at each span with shear spans of span/4. The longitudinal shear failure of each slab is evaluated and the measured mid-span deflection, the end slip and the mid-span steel and concrete strains are also presented and discussed. Redistribution of bending moment in each slab is presented and discussed. A finite element model is proposed and verified by experimental data using interface element to model the bond properties between steel decking and concrete slab and investigate the ultimate strength of continuous composite concrete slabs.

46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, CONTROL PANEL LEVEL (2ND DECK) OF ETHER AND ALCOHOL STILL BUILDING, LOOKING NORTH, SHOWING TWO ALCOHOL DISTILLATION TOWERS BEHIND 'MIXED SOLVENT UNIT' CONTROL PANEL. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

Evaluation of several types of curing and protective materials for concrete : final report on part II : installation report and initial condition survey of bridge decks.

DOT National Transportation Integrated Search

1970-01-01

Thirty-nine test panels were installed on three interstate bridges to evaluate several combinations of curing and protective treatments for concrete. Panels were cured with white pigmented liquid membrane and white polyethylene, both with and without...

Tool for analysis of early age transverse cracking of composite bridge decks.

DOT National Transportation Integrated Search

2011-08-29

"Executive Summary: Computational methods and associated software were developed : to compute stresses in HP concrete composite bridge decks due to temperature, shrinkage, and : vehicle loading. The structural analysis program uses a layered finite e...

Fiberglass reinforced polymer composite bridge deck construction in Illinois

DOT National Transportation Integrated Search

2002-09-01

An experiment was conducted using a fiber reinforced polymer composite material for the bridge deck of a low volume bridge. The test location was on South Fayette Street over the Town Brook in Jacksonville, Illinois. This project included removal of ...

Cone calorimeter tests of wood-based decking materials

Treesearch

Robert H. White; Mark A. Dietenberger; Nicole M. Stark

2007-01-01

New technologies in building materials have resulted in the use of a wide variety of materials in decks. As part of our effort to address fire concerns in the wildland-urban interface, the Forest Products Laboratory has been examining the fire performance of decking products. In addition to preservative-treated wood, decking products include wood-plastic composites and...

STS-29 Commander Coats in JSC fixed base (FB) shuttle mission simulator (SMS)

NASA Technical Reports Server (NTRS)

1986-01-01

STS-29 Discovery, Orbiter Vehicle (OV) 103, Commander Michael L. Coats sits at commanders station forward flight deck controls in JSC fixed base (FB) shuttle mission simulator (SMS). Coats, wearing communications kit assembly headset and flight coveralls, looks away from forward control panels to aft flight deck. Pilots station seat back appears in foreground. FB-SMS is located in JSC Mission Simulation and Training Facility Bldg 5.

Optimization of wood plastic composite decks

NASA Astrophysics Data System (ADS)

Ravivarman, S.; Venkatesh, G. S.; Karmarkar, A.; Shivkumar N., D.; Abhilash R., M.

2018-04-01

Wood Plastic Composite (WPC) is a new class of natural fibre based composite material that contains plastic matrix reinforced with wood fibres or wood flour. In the present work, Wood Plastic Composite was prepared with 70-wt% of wood flour reinforced in polypropylene matrix. Mechanical characterization of the composite was done by carrying out laboratory tests such as tensile test and flexural test as per the American Society for Testing and Materials (ASTM) standards. Computer Aided Design (CAD) model of the laboratory test specimen (tensile test) was created and explicit finite element analysis was carried out on the finite element model in non-linear Explicit FE code LS - DYNA. The piecewise linear plasticity (MAT 24) material model was identified as a suitable model in LS-DYNA material library, describing the material behavior of the developed composite. The composite structures for decking application in construction industry were then optimized for cross sectional area and distance between two successive supports (span length) by carrying out various numerical experiments in LS-DYNA. The optimized WPC deck (Elliptical channel-2 E10) has 45% reduced weight than the baseline model (solid cross-section) considered in this study with the load carrying capacity meeting acceptance criterion (allowable deflection & stress) for outdoor decking application.

Research notes : wearing surfaces for plastic bridge decks.

DOT National Transportation Integrated Search

2005-07-01

Fiber reinforced polymer (FRP) composite bridge decks based on fiberglass materials are being installed on bridges across the country. In addition to being light-weight and quick to install, these decks do not corrode. Oregon has three state-owned an...

75 FR 16651 - Airworthiness Directives; The Boeing Company Model 747-200C and -200F Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... upper chord of the upper deck floor beams in Area 5, and the inspection for fatigue cracking in the.... That AD currently requires repetitive inspections to find fatigue cracking in the floor panel... additional repetitive inspections to find fatigue cracking in the floor panel attachment fastener holes of...

Rapid replacement of Tangier Island bridges including lightweight and durable fiber-reinforced polymer deck systems.

DOT National Transportation Integrated Search

2009-01-01

Fiber-reinforced polymer (FRP) composite cellular deck systems were used as new bridge decks on two replacement bridges on Tangier Island, Virginia. The most important characteristics of this application were reduced self-weight and increased durabil...

15. NBS TOP SIDE CONTROL ROOM. THE SUIT SYSTEMS CONSOLE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. NBS TOP SIDE CONTROL ROOM. THE SUIT SYSTEMS CONSOLE IS USED TO CONTROL AIR FLOW AND WATER FLOW TO THE UNDERWATER SPACE SUIT DURING THE TEST. THE SUIT SYSTEMS ENGINEER MONITORS AIR FLOW ON THE PANEL TO THE LEFT, AND SUIT DATA ON THE COMPUTER MONITOR JUST SLIGHTLY TO HIS LEFT. WATER FLOW IS MONITORED ON THE PANEL JUST SLIGHTLY TO HIS RIGHT AND TEST VIDEO TO HIS FAR RIGHT. THE DECK CHIEF MONITORS THE DIVER'S DIVE TIMES ON THE COMPUTER IN THE UPPER RIGHT. THE DECK CHIEF LOGS THEM IN AS THEY ENTER THE WATER, AND LOGS THEM OUT AS THEY EXIT THE WATER. THE COMPUTER CALCULATES TOTAL DIVE TIME. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

Standard Practice for the Selection and Application of Marine Deck Coverings

DTIC Science & Technology

1992-07-01

floors to reduce the transmission of noise and vibrations. These typically consist of layers of mineral wool or mineral wool panel sections with a...crew efficiency. Floating deck systems are generally composed of an insulating material such as mineral wool that are laid loose on the structural...Chapter II-2, Part A, Regulation 3(c). Sound Reduction Index - 44 dB Sound Insulation Index (Ia) - 47 dB Density of Mineral Wool - 10 pounds per

General view of the middeck of the Orbiter Discovery while ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the mid-deck of the Orbiter Discovery while in the Orbiter Processing Facility at Kennedy Space Center. The view is looking through the air lock and into the payload bay. In the foreground note the ladders and access hatches to the flight deck and the ground support panels used to protect the floors. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Strategic sensor locations of FPR bridge decks

NASA Astrophysics Data System (ADS)

Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

2003-07-01

Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

KSC-2011-8368

NASA Image and Video Library

2011-12-22

CAPE CANAVERAL, Fla. – In Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida, a plethora of switches fills the control panel on the flight deck of space shuttle Atlantis. The flight deck is illuminated one last time as preparations are made for the shuttle's final power down during Space Shuttle Program transition and retirement activities. Atlantis is being prepared for public display in 2013 at the Kennedy Space Center Visitor Complex. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann

ABC deck panel testing.

DOT National Transportation Integrated Search

2013-09-01

Accelerated Bridge Construction techniques have resulted in innovative options that : save time and money during the construction of bridges. One such group of techniques : that has generated considerable interest is the usage of individual precast c...

Hillsboro Canal bridge monitoring.

DOT National Transportation Integrated Search

2011-12-01

This report describes the implementation of a testing and monitoring program for bridge 930338 in Belle Glade. Glass-fiber : reinforced polymer (GFRP) deck panels and plates were installed over an existing steel superstructure using grouted steel : s...

STS-44 Atlantis, OV-104, Pilot Henricks in FB-SMS training at JSC

NASA Technical Reports Server (NTRS)

1991-01-01

STS-44 Atlantis, Orbiter Vehicle (OV) 104, Pilot Terence T. Henricks, seated at the pilots station on the forward flight deck, reviews checklists before a flight simulation in the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. Surrounding Henricks are the seat back, the overhead panels, forward panels, and forward windows.

46 CFR 72.05-30 - Windows and airports.

Code of Federal Regulations, 2013 CFR

2013-10-01

... open decks or enclosed promenades need not have wire inserted glass. (g) Skylights to spaces containing... skylights, it shall be of the wire inserted type. The glass panels shall be fitted with permanently attached...

46 CFR 72.05-30 - Windows and airports.

Code of Federal Regulations, 2012 CFR

2012-10-01

... open decks or enclosed promenades need not have wire inserted glass. (g) Skylights to spaces containing... skylights, it shall be of the wire inserted type. The glass panels shall be fitted with permanently attached...

46 CFR 72.05-30 - Windows and airports.

Code of Federal Regulations, 2014 CFR

2014-10-01

... open decks or enclosed promenades need not have wire inserted glass. (g) Skylights to spaces containing... skylights, it shall be of the wire inserted type. The glass panels shall be fitted with permanently attached...

Evaluation of restraint system concepts for the Japanese Experiment Module flight demonstration

NASA Technical Reports Server (NTRS)

Sampaio, Carlos E.; Fleming, Terence F.; Stuart, Mark A.; Backemeyer, Lynn A.

1995-01-01

The current International Space Station configuration includes a Japanese Experiment Module which relies on a large manipulator and a smaller dexterous manipulator to operate outside the pressurized environment of the experiment module. The module's flight demonstration is a payload that will be mounted in the aft flight deck on STS-87 to evaluate a prototype of the dexterous manipulator. Since the payload operations entail two 8-hour scenarios on consecutive days, adequate operator restraint at the workstation will be critical to the perceived success or failure of the payload. Simulations in reduced gravity environment on the KC-135A were the only way to evaluate the restraint systems and workstation configuration. Two astronaut and two non-astronaut operators evaluated the Advanced Lower Body Extremities Restraint Test and a foot loop restraint system by performing representative tasks at the workstation in each of the two restraint systems; at the end of each flight they gave their impressions of each system and the workstation. Results indicated that access to the workstation switch panels was difficult and manipulation of the hand controllers forced operators too low for optimal viewing of the aft flight deck monitors. The workstation panel should be angled for better visibility, and infrequently used switches should be on the aft flight deck panel. Pitch angle and placement of the hand controllers should optimize the operator's eye position with respect to the monitors. The lower body restraint was preferred over the foot loops because it allowed operators to maintain a more relaxed posture during long-duration tasks, its height adjustability allowed better viewing of aft flight deck monitors, and it provided better restraint for reacting forces imparted on the operator at the workstation. The foot loops provide adequate restraint for the flight demonstration tasks identified. Since results will impact the design of the workstation, both restraints should be flown and used during operation of the flight demonstration payload to evaluate the effect of restraint during long-duration tasks.

Heat insulating system for a fast reactor shield slab

DOEpatents

Kotora Jr., James; Groh, Edward F.; Kann, William J.; Burelbach, James P.

1986-04-01

Improved thermal insulation for a nuclear reactor deck comprising many helical coil springs disposed in generally parallel, side-by-side laterally overlapping or interfitted relationship to one another so as to define a three-dimensional composite having both metal and voids between the metal, and enclosure means for holding the composite to the underside of the deck.

Heat insulating system for a fast reactor shield slab

DOEpatents

Kotora, Jr., James; Groh, Edward F.; Kann, William J.; Burelbach, James P.

1986-01-01

Improved thermal insulation for a nuclear reactor deck comprising many helical coil springs disposed in generally parallel, side-by-side laterally overlapping or interfitted relationship to one another so as to define a three-dimensional composite having both metal and voids between the metal, and enclosure means for holding the composite to the underside of the deck.

Heat insulating system for a fast reactor shield slab

DOEpatents

Kotora, J. Jr.; Groh, E.F.; Kann, W.J.; Burelbach, J.P.

1984-04-10

Improved thermal insulation for a nuclear reactor deck comprises many helical coil springs disposed in generally parallel, side-by-side laterally overlapping or interfitted relationship to one another so as to define a three-dimensional composite having both metal and voids between the metal, and enclosure means for holding the composite to the underside of the deck.

Advances and challenges of wood polymer composites

Treesearch

Roger M. Rowell

2006-01-01

Wood flour and fiber have been blended with thermoplastic such as polyethylene, polypropylene, polylactic acid and polyvinyl chloride to form wood plastic composites (WPC). WPCs have seen a large growth in the United States in recent years mainly in the residential decking market with the removal of CCA treated wood decking from residential markets. While there are...

KSC-2011-8369

NASA Image and Video Library

2011-12-22

CAPE CANAVERAL, Fla. – In Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida, the controller used during docking to the airlock of space shuttle Atlantis stands among the switches filling the control panel on the flight deck. The flight deck is illuminated one last time as preparations are made for the shuttle's final power down during Space Shuttle Program transition and retirement activities. Atlantis is being prepared for public display in 2013 at the Kennedy Space Center Visitor Complex. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann

Stiffness and strength of fiber reinforced polymer composite bridge deck systems

NASA Astrophysics Data System (ADS)

Zhou, Aixi

This research investigates two principal characteristics that are of primary importance in Fiber Reinforced Polymer (FRP) bridge deck applications: STIFFNESS and STRENGTH. The research was undertaken by investigating the stiffness and strength characteristics of the multi-cellular FRP bridge deck systems consisting of pultruded FRP shapes. A systematic analysis procedure was developed for the stiffness analysis of multi-cellular FRP deck systems. This procedure uses the Method of Elastic Equivalence to model the cellular deck as an equivalent orthotropic plate. The procedure provides a practical method to predict the equivalent orthotropic plate properties of cellular FRP decks. Analytical solutions for the bending analysis of single span decks were developed using classical laminated plate theory. The analysis procedures can be extended to analyze continuous FRP decks. It can also be further developed using higher order plate theories. Several failure modes of the cellular FRP deck systems were recorded and analyzed through laboratory and field tests and Finite Element Analysis (FEA). Two schemes of loading patches were used in the laboratory test: a steel patch made according to the ASSHTO's bridge testing specifications; and a tire patch made from a real truck tire reinforced with silicon rubber. The tire patch was specially designed to simulate service loading conditions by modifying real contact loading from a tire. Our research shows that the effects of the stiffness and contact conditions of loading patches are significant in the stiffness and strength testing of FRP decks. Due to the localization of load, a simulated tire patch yields larger deflection than the steel patch under the same loading level. The tire patch produces significantly different failure compared to the steel patch: a local bending mode with less damage for the tire patch; and a local punching-shear mode for the steel patch. A deck failure function method is proposed for predicting the failure of FRP decks. Using developed laminated composite theories and FEA techniques, a strength analysis procedure containing ply-level information was proposed and detailed for FRP deck systems. The behavior of the deck's unsupported (free) edges was also investigated using ply-level FEA.

Field testing and evaluation of a demonstration timber bridge.

DOT National Transportation Integrated Search

2012-02-01

Asphalt wearing surfaces are commonly used on timber bridges with transverse glued-laminated deck panel systems to help protect the timber components. However, poor performance of these asphalt wearing surfaces in the past has resulted in repeated re...

Development of precast bridge deck overhang system : technical report.

DOT National Transportation Integrated Search

2011-07-01

The implementation of full-depth, precast overhang panel systems has the potential to improve constructability, : productivity, and make bridges more economical. Initial testing and analyses reported in the 0-6100-2 report resulted in : a design that...

Smart FRP Composite Sandwich Bridge Decks in Cold Regions

DOT National Transportation Integrated Search

2011-07-01

In this study, new and integrated Smart honeycomb Fiber-Reinforced Polymer (S-FRP) : sandwich materials for various transportation construction applications, with particular emphasis : on highway bridge decks in cold regions, were developed and teste...

Toward Successful Implementation of Prefabricated Deck Panels to Accelerate the Bridge Construction Process

DOT National Transportation Integrated Search

2016-08-01

The development of accelerated bridge construction (ABC) techniques and connection details has become a national research focus. With the aging of the interstate system and many bridges on key routes requiring extensive rehabilitation or replacement,...

Polyurethane foam infill for fiber-reinforced polymer (FRP) bridge deck panels.

DOT National Transportation Integrated Search

2014-05-01

Although still in their infancy, fiber-reinforced polymer (FRP) bridges have shown great promise in eliminating corrosion : concerns and meeting (or exceeding) FHWAs goal of 100-year life spans for bridges. While FRP bridges are cost-effective in ...

Demonstration of Thermoplastic Composite I-Beam Design Bridge at Camp Mackall, NC: Final Report on Projects FY08-16 and FY09-31

DTIC Science & Technology

2017-12-01

fastened to the deck surface, with spaces approximately every 6 ft (1.8 m) to allow water to run off... run the length of the bridge, touching edge to edge. The girders are through bolted to the pile caps. Decking is affixed to the girders with deck...fastened to the deck surface, with spaces approximately every 6 ft (1.8 m) to allow water to run off. ERDC/CERL TR-17-45 49 Figure 43. Holes

Smart FRP Composite Sandwich Bridge Decks in Cold Regions

DOT National Transportation Integrated Search

2011-07-01

In this study, new and integrated Smart honeycomb Fiber-Reinforced Polymer (S-FRP) sandwich materials for various transportation construction applications, with particular emphasis on highway bridge decks in cold regions, were developed and tested. T...

STS-36 Commander Creighton and Pilot Casper on flight deck during JSC training

NASA Technical Reports Server (NTRS)

1989-01-01

In their forward flight deck stations, STS-36 Commander John O. Creighton and Pilot John H. Casper discuss procedures prior to participating in JSC Fixed Based (FB) Shuttle Mission Simulator (SMS) exercises in the Shuttle Simulation and Training Facility Bldg 5. Creighton (left) sits in front of the commanders station controls and Casper (right) in front of the pilots station controls. Checklists are posted in various positions on the forward control panels as the crewmembers prepare for the FB-SMS simulation and their Department of Defense (DOD) flight aboard Atlantis, Orbiter Vehicle (OV) 104.

The Role of Persons as Organizing Categories in Social Cognition.

DTIC Science & Technology

1982-01-01

person information, the observer is automatically aware of who the person is (thereby involving category descriminability ) and which person is being...four white males. These photographs were selected from Makio 1978, the Ohio State University yearbook. In addition to the overlap of racial and gender...Two of the bogus decks mimicked the racial /gender composition of High Discriminability decks and the other two, that of Low Discriminability decks

Demonstration and Validation of a Lightweight Composite Bridge Deck Technology as an Alternative to Reinforced Concrete

DTIC Science & Technology

2016-08-01

Abstract Cyclic loading and weathering of reinforced concrete bridge decks cause corrosion of reinforcement steel , which leads to cracking, potholes...inforcement steel , on a deteriorated concrete bridge at Redstone Arsenal, AL. A pultruded deck system made by Zellcomp, Inc., was selected for...16 Figure 13. Form for grout haunch fabricated by tack welding steel strips to the top of the girder

Analysis and design of composite slab by varying different parameters

NASA Astrophysics Data System (ADS)

Lambe, Kedar; Siddh, Sharda

2018-03-01

Composite deck slabs are in demand because of its faster, lighter and economical construction work. Composite slab consists of cold formed deck profiled sheet and concrete either lightweight or normal. Investigation of shear behaviour of the composite slab is very complex. Shear bond strength depends on the various parameter such as a shape of sheeting, a thickness of the sheet, type of embossment and its frequency of use, shear stiffener or intermediate stiffener, type of load, an arrangement of load, length of shear span, the thickness of concrete and support friction etc. In present study finite element analysis is carried out with ABAQUS 6.13, a simply supported composite slab is considered for the investigation of the shear bond behaviour of the composite slab by considering variation in three different parameters, the shape of a sheet, thickness of sheet and shear span. Different shear spans of two different shape of cold formed deck profiled sheet i.e. with intermediate stiffeners and without intermediate stiffeners are considered with two different thicknesses (0.8 mm and 1.2 mm) for simulation. In present work, simulation of models has done for static loading with 20 mm mesh size is considered.

Performance evaluation of concrete bridge decks reinforced with MMFX and SSC rebars.

DOT National Transportation Integrated Search

2006-01-01

This report investigates the performance of bridge decks reinforced with stainless steel clad (SSC) and micro-composite multistructural formable steel (MMFX) rebars. The two-span Galloway Road Bridge on route CR5218 over North Elkhorn Creek in Scott ...

29 CFR 1926.1400 - Scope.

Code of Federal Regulations, 2012 CFR

2012-07-01

... loads. (3) Automotive wreckers and tow trucks when used to clear wrecks and haul vehicles. (4) Digger... not limited to: Precast concrete members or panels, roof trusses (wooden, cold-formed metal, steel, or... structural steel member (for example, steel joists, beams, columns, steel decking (bundled or unbundled) or a...

Precast concrete elements for accelerated bridge construction : laboratory testing of precast substructure components, Boone County bridge.

DOT National Transportation Integrated Search

2009-01-01

Vol. 1-1: In July 2006, construction began on an accelerated bridge project in Boone County, Iowa that was composed of precast substructure : elements and an innovative, precast deck panel system. The superstructure system consisted of full-depth dec...

Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface-Bonded Carbon Fiber-Reinforced Polymer

DOT National Transportation Integrated Search

2009-05-01

"This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort...

Evaluation of wearing surface materials for FRP bridge decks : final report.

DOT National Transportation Integrated Search

2005-07-01

The wearing surface on many fiber reinforced polymer (FRP) composite bridge decks have cracked or delaminated after only a short time in service. Consequently, a set of tests were conducted on four wearing surface products in order to select the mate...

Development of a nondestructive evaluation method for FRP bridge decks

NASA Astrophysics Data System (ADS)

Brown, Jeff; Fox, Terra

2010-05-01

Open steel grids are typically used on bridges to minimize the weight of the bridge deck and wearing surface. These grids, however, require frequent maintenance and exhibit other durability concerns related to fatigue cracking and corrosion. Bridge decks constructed from composite materials, such as a Fiber-reinforced Polymer (FRP), are strong and lightweight; they also offer improved rideability, reduced noise levels, less maintenance, and are relatively easy to install compared to steel grids. This research is aimed at developing an inspection protocol for FRP bridge decks using Infrared thermography. The finite element method was used to simulate the heat transfer process and determine optimal heating and data acquisition parameters that will be used to inspect FRP bridge decks in the field. It was demonstrated that thermal imaging could successfully identify features of the FRP bridge deck to depths of 1.7 cm using a phase analysis process.

STS-44 Atlantis, OV-104, crewmembers participate in FB-SMS training at JSC

NASA Technical Reports Server (NTRS)

1991-01-01

STS-44 Atlantis, Orbiter Vehicle (OV) 104, Commander Frederick D. Gregory (left) and Pilot Terence T. Henricks (right), positioned at their appointed stations on the forward flight deck, are joined by Mission Specialist (MS) F. Story Musgrave (center). The crewmembers are participating in a flight simulation in the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. Gregory in the commanders seat, Musgrave sitting on center console, and Henricks in the pilots seat look back toward the aft flight deck and the photographer. Seat backs appear in the foreground and forward control panels in the background.

STS-36 Pilot Casper reaches for laptop computer on OV-104's flight deck

NASA Image and Video Library

1990-03-03

STS036-03-027 (3 March 1990) --- STS-36 Pilot John H. Casper reaches for the shuttle portable onboard computer (SPOC), a laptop computer, while at the pilots station on the forward flight deck of Atlantis, Orbiter Vehicle (OV) 104. Casper, seated in the pilot’s seat, lifts the SPOC from the forward window ledge. Appearing around him are forward crew compartment windows, the head up display (HUD), the flight mirror assembly, and a checklist attached to control panel O3. Casper and four other astronauts spent four days, 10 hours and 19 minutes aboard the spacecraft for a Department of Defense (DOD) devoted mission.

Load Distribution Factors for Composite Multicell Box Girder Bridges

NASA Astrophysics Data System (ADS)

Tiwari, Sanjay; Bhargava, Pradeep

2017-12-01

Cellular steel section composite with a concrete deck is one of the most suitable superstructures in resisting torsional and warping effects induced by highway loading. This type of structure has inherently created new design problems for engineers in estimating its load distribution when subjected to moving vehicles. Indian Codes of Practice does not provide any specific guidelines for the design of straight composite concrete deck-steel multi-cell bridges. To meet the practical requirements arising during the design process, a simple design method is needed for straight composite multi-cell bridges in the form of load distribution factors for moment and shear. This work presents load distribution characteristics of straight composite multi-cell box girder bridges under IRC trains of loads.

Smart FRP Composite Sandwich Bridge Decks in Cold Regions

DOT National Transportation Integrated Search

2011-07-01

What if every time a bridge on a lonely road got icy, it automatically notified the local DOT to begin ice-control safety measures? What if a bridge could tell someone : every time an overloaded truck hit the decking, or when the trusses under it beg...

Environmental durability of reinforced concrete deck girders strengthened for shear with surface-bonded carbon fiber-reinforced polymer : final report.

DOT National Transportation Integrated Search

2009-05-01

This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort ...

Environmental durability of reinforced concrete deck girders strengthened for shear with surface bonded carbon fiber-reinforced polymer : final report.

DOT National Transportation Integrated Search

2009-05-01

This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced : concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effor...

Field implementation of fiber-reinforced polymer (FRP) deck panels.

DOT National Transportation Integrated Search

2017-06-01

Jeffery S. Volz, S.E., P.E., Ph.D., Kamal H. Khayat, PhD, P.Eng. http://orcid.org/0000-0003-1431-0715, Soo Duck Hwang, Ph.D. http://orcid.org/0000-0003-2178-1531, Hesham Tuwair, Ph.D., Jonathan T. Drury, Amy S. Crone : Although still in their infancy...

3. VIEW TO NORTHEAST, NORTH SIDE OF CENTER DRUM MACHINERY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW TO NORTHEAST, NORTH SIDE OF CENTER DRUM MACHINERY ROOM. MOTOR #1 COMPARTMENT IN REAR, AUXILIARY MOTOR DRIVE SHAFT, POWER PANELS ON BACK OF AUXILIARY MOTOR HOUSE. BRIDGE DECK FRAMING ABOVE. - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

A comment on the use of polymer-impregnated concrete in bridge decks to achieve a reduction in material volume and first cost.

DOT National Transportation Integrated Search

1975-01-01

Three 180', simple span, composite plate girder structures were designed to approximate the material requirements and first cost associated with a polymer-impregnated concrete as compared to those for a conventional concrete bridge deck. The structur...

IUS with Magellan spacecraft drifts into space after STS-30 deployment

NASA Image and Video Library

1989-05-04

STS030-71-063 (4 May 1989) --- This scene is one of two released by NASA showing the process of solar array panel deployment on the Magellan spacecraft. Panels are not fully extended in this frame. The spacecraft had earlier been released by the STS-30 crewmembers to begin its long journey to the planet Venus for an extensive radar mapping mission. The frame was photographed through Atlantis? aft flight deck windows with a handheld 70mm camera. The complementary photograph is STS030-71-070.

Ferguson Troubleshoots GPC 3

NASA Image and Video Library

2011-07-11

S135-E-007350 (11 July 2011) --- NASA astronaut Chris Ferguson, STS-135 mission commander, toggles switches on the overhead panel of the forward flight deck of the space shuttle Atlantis. The image was recorded during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

Using wood quality measures to evaluate second-growth redwood

Treesearch

Stephen L. Quarles; Yana Vlachovic

2012-01-01

Redwood (Sequoia sempervirens) a valued species for use in appearance grade applications, such as decking, exterior siding and interior paneling, because of its dimensional stability. It is also valued for certain exterior-use applications because of its natural decay resistance. Studies have found that young-growth redwood is less resistant to...

Orbiter fire rescue and crew escape training for EVA crew systems support

NASA Image and Video Library

1993-01-28

Photos of orbiter fire rescue and crew escape training for extravehicular activity (EVA) crew systems support conducted in Bldg 9A Crew Compartment Trainer (CCT) and Fuel Fuselage Trainer (FFT) include views of CCT interior of middeck starboard fuselage showing middeck forward (MF) locker and COAS assembly filter, artiflex film and camcorder bag (26834); launch/entry suit (LES) helmet assembly, neckring and helmet hold-down assembly (26835-26836); middeck aft (MA) lockers (26837); area of middeck airlock and crew escape pole (26838); connectors of crew escape pole in the middeck (268390); three test subjects in LES in the flight deck (26840); emergency side hatch slide before inflated stowage (26841); area of below adjacent to floor panel MD23R (26842); a test subject in LES in the flight deck (26843); control board and also showing sign of "orbital maneuvering system (OMS) secure and OMS TK" (26844); test subject in the flight deck also showing chart of "ascent/abort summary" (26845).

Astronaut Young at the commander's station

NASA Image and Video Library

1983-11-28

STS009-128-858 (28 Nov-8 Dec 1983) --- Astronaut John W. Young takes notes in the commander?s station on the flight deck of the Columbia. The cathode ray tube (CRT) among the forward panels displays the orbiter?s position in relation to the Earth on its monitor. Astronaut Brewster H. Shaw Jr., pilot, took this photograph.

76 FR 67675 - Notice of Preliminary Determination of Sales at Less Than Fair Value, Postponement of Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-02

... storage compartments accessible through one or more separate external doors or drawers or a combination thereof; An upper-most interior storage compartment(s) that is accessible through an external door or... external metal shell, (b) a back panel, (c) a deck, (d) an interior plastic liner, (e) wiring, and (f...

Pilot Fullerton reviews FDF and TAGS printout on forward flight deck

NASA Technical Reports Server (NTRS)

1982-01-01

Pilot Fullerton, wearing communications kit assembly (ASSY) mini headset (HDST), reviews flight data file (FDF) checklist and text and graphics system (TAGS) printout (ticker tape) while in pilots ejection seat (S2). Pilot Station control panels F4, F7, F8, O3, window shade, and portable oxygen system (POS) assy appear in view.

IUS with Magellan spacecraft drifts into space after STS-30 deployment

NASA Image and Video Library

1989-05-04

STS030-71-070 (4 May 1989) --- This scene is one of two released by NASA showing the process of solar array panel deployment on the Magellan spacecraft. Though partially blended into the backdrop of the blackness of space, it appears the two panels are fully extended in this frame. The spacecraft had earlier been released by the STS-30 crewmembers to begin its long journey to the planet Venus for an extensive radar mapping mission. The frame was photographed through Atlantis' aft flight deck windows with a handheld 70mm camera. The complementary photograph is STS030-71-063.

50 CFR 679.93 - Amendment 80 Program recordkeeping, permits, monitoring, and catch accounting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... where the observer collects species composition samples. (5) Fish on deck. No fish are allowed to remain on deck unless an observer is present, except for fish inside the codend and fish accidentally... § 679.4(l)(2)(i) using trawl gear and fishing or receiving fish in the BSAI and in adjacent waters open...

Playback Station #2 for Cal Net and 5-day-recorder tapes

USGS Publications Warehouse

Eaton, Jerry P.

1978-01-01

A second system (Playback Station #2) has been set up to play back Cal Net 1" tapes and 5-day-recorder 1/2" tapes. As with the first playback system (Playback Station #1) the tapes are played back on a Bell and Howell VR3700B tape deck and the records are written out on a 16-channel direct-writing Siemens "0scillomink." Separate reproduce heads, tape guides, and tape tension sensor rollers are required for playing back 111 tapes and 1/2" tapes, but changing these tape deck components is a simple task that requires only a few minutes. The discriminators, patch panels, selector switches, filters, time code translators, and signal conditioning circuits for the time code translators and for the tape-speed-compensation signal are all mounted in an equipment rack that stands beside the playback tape deck. Changing playback speeds (15/16 ips or 3 3/4 ips) or changing from Cal Net tapes to 5-day-recorder tapes requires only flipping a few switches and/or changing a few patch cables on the patch panel (in addition to changing the reproduce heads, etc., to change from 1" tape to 1/2" tape). For the Cal Net tapes, the system provides for playback of 9 data channels (680 Hz thru 3060 Hz plus 400 Hz) and 3 time signals (IRIG-E, IRIG-C, and WWVB) at both 15/16 ips (x1 speed) and 3 3/4 ips (x4 speed). Available modes of compensation (using either a 4688 Hz reference or a 3125 Hz reference) are subtractive, capstan, capstan plus subtractive, or no compensation.

Bonded and Stitched Composite Structure

NASA Technical Reports Server (NTRS)

Zalewski, Bart F. (Inventor); Dial, William B. (Inventor)

2014-01-01

A method of forming a composite structure can include providing a plurality of composite panels of material, each composite panel having a plurality of holes extending through the panel. An adhesive layer is applied to each composite panel and a adjoining layer is applied over the adhesive layer. The method also includes stitching the composite panels, adhesive layer, and adjoining layer together by passing a length of a flexible connecting element into the plurality of holes in the composite panels of material. At least the adhesive layer is cured to bond the composite panels together and thereby form the composite structure.

Multifunctional Inflatable Structure Being Developed for the PowerSphere Concept

NASA Technical Reports Server (NTRS)

Peterson, Todd T.

2004-01-01

NASA has funded a collaborative team of The Aerospace Corporation, ILC Dover, Lockheed Martin, and NASA Glenn Research Center to develop the Multifunctional Inflatable Structure (MIS) for a "PowerSphere" concept through a NASA Research Announcement. This power system concept has several advantages, including a high collection area, low weight and stowage volume, and the elimination of all solar array pointing mechanisms. The current 3-year effort will culminate with the fabrication and testing of a fully functional engineering development unit. The baseline design of the Power-Sphere consists of two opposing semispherical domes connected to a central spacecraft. Each semispherical dome consists of hexagonal and pentagonal solar cell panels that together form a geodetic sphere. Inflatable ultraviolet (UV) rigidizable tubular hinges between the solar cell panels and UV rigidizable isogrid center columns with imbedded flex circuitry form the MIS. The reference configuration for the PowerSphere is a 0.6-m-diameter (fully deployed) spacecraft with a total mass budget of 4 kg (1 kg for PowerSphere, 3 kg for spacecraft) capable of producing 29 W of electricity with 10-percent-efficient thin-film solar cells. In a stowed configuration, the solar cell panels will be folded sequentially to the outside of the instrument decks. The center column will be z-folded between the instrument decks and the spacecraft housing for packaging. The instrument panel will secure the z-folded stack with launch ties. After launch, once the release tie is triggered, the center column and hinge tubes will inflate and be rigidized in their final configurations by ultraviolet radiation. The overall PowerSphere deployment sequence is shown pictorially in the following illustration.

New set of solar arrays deployed on Hubble Space Telescope

NASA Image and Video Library

1993-12-09

STS061-99-002 (2-13 Dec 1993) --- The new set of solar array panels deployed on the Hubble Space Telescope (HST) is backdropped against the blackness of space and a widely cloud-covered area on Earth. The 70mm frame was exposed by one of the Space Shuttle Endeavour's seven crew members on the aft flight deck.

Is the semi-direct effect for smoke overlying stratocumulus clouds overrated? Circulation variability and radiative impacts Reconsidered for the southeast Atlantic

NASA Astrophysics Data System (ADS)

Zuidema, P.; Adebiyi, A. A.; Abel, S.

2013-12-01

Smoke produced by seasonal biomass burning in the southwestern African savannah can be advected westward over the Atlantic Ocean, where it mostly overlies a major planetary stratocumulus deck. Shortwave absorption by the smoke warms the atmosphere, stabilizing it, thereby reducing cloud-top entrainment and encouraging cloud thickening (the semi-direct effect). Associated dynamical and moisture effects that may be convoluted with the semi-direct effect have received less attention, and are examined here. Radiosondes at their original resolution are available almost daily from the remote St. Helena Island (15.9oS, 5.6oW), from 2000 through 2012. These are combined with MODIS fine-mode aerosol optical depth (AODf), and composited into pristine and polluted days for the September-October months. Increases in AODf are associated with increases in 750-500 hPa moisture content, often capped by sharply defined temperature and moisture inversions. These corroborate similar associations evident in SAFARI-2000 data. The composite-mean additional moisture of ~2.2 g kg-1 produces a diurnal-mean shortwave heating rate of ~ 0.2 K day-1 in addition to that from smoke. Similarly-composited ERA-Interim Reanalysis profiles match the radiosonde composites more closely than do those based on MERRA or NCEP Reanalyses. ERA-Interim spatial composites show that the polluted conditions are associated with a stronger mid-level anticyclone over southern Africa, facilitating the westward and (offshore) southward transport of both smoke and moisture. The shallower surface-based south Atlantic anticyclone shifts to east, strengthening the low-level coastal jet exiting into the stratocumulus deck, and enhancing warm temperature advection above the main stratocumulus deck. This increases the lower tropospheric stability (θ800-θ1000) and enhances the surface fluxes, strengthening the stratocumulus deck. Thus, the dynamics encouraging smoke transport and the additional shortwave absorption by moisture act in concert with the semi-direct effect to increase the cloud fraction and thicken the clouds. The associations between smoke, moisture and circulation highlight the difficulty of distinguishing aerosol effects on the Atlantic stratocumulus deck from meteorological effects.The uncertainties inherent to the realistic modeling of the smoke, cloud, their interactions and their climatic effects motivate a field deployment, ONFIRE, proposed to the southeast Atlantic in 2016, that will also be discussed.

Operation UPSHOT-KNOTHOLE, Nevada Proving Grounds, March-June 1953. Project 3.5 Tests on the Response of Wall and Roof Panels and the Transmission of Load to Supporting Structure

DTIC Science & Technology

1955-05-01

56 4.23 Postshot, 3.5ba, Interior of Test Cell . . . . . . . . • • 57 4.24 Postshot, 35.Sbb, Damage to Precast Concrete Channel Roof 6...Predicted Applied and Measured Transmitted Forces, Roof Panel 3.5bb (3-1/2 in. precast concrete channels on steel purlins) . . . o . o . ... . ... 104 5.16...truss rafters 3.Sba Bowstring truss with wood 4500 4200 10 7.1 10 decking, tar and gravel roofing 3.5bb 3-1/2 in. precast concrete channels on steel

Prediction on flexural strength of encased composite beam with cold-formed steel section

NASA Astrophysics Data System (ADS)

Khadavi, Tahir, M. M.

2017-11-01

A flexural strength of composite beam designed as boxed shaped section comprised of lipped C-channel of cold-formed steel (CFS) facing each other with reinforcement bars is proposed in this paper. The boxed shaped is kept restrained in position by a profiled metal decking installed on top of the beam to form a slab system. This profiled decking slab is cast by using self-compacting concrete where the concrete is in compression when load is applied to the beam. Reinforcement bars are used as shear connector between slab and CFS as beam. A numerical analysis method proposed by EC4 is used to predict the flexural strength of the proposed composite beam. It was assumed that elasto-plastic behaviour is developed in the cross -sectional of the proposed beam. The calculated predicted flexural strength of the proposed beam shows reasonable flexural strength for cold-formed composite beam.

Blast and Impact Resistant Composite Structures for Navy Ships

DTIC Science & Technology

2013-03-15

Navy cargo ships, Air Force tactical shelters, Air Force runway matting, vehicular bridge decks, railcar floors and wind turbine blades. The US Army...bridge decks, railcar floors and wind turbine blades. NAVY RELEVANCE Producing stronger, safer and more cost-effective platforms for the new generation...floors and wind turbine blades. 32 NAVY RELEVANCE Producing stronger, safer and more cost-effective platforms for the new generation naval ships

Durability of Capped Wood Plastic Composites

Treesearch

Mark Mankowski; Mark J. Manning; Damien P. Slowik

2015-01-01

Manufacturers of wood plastic composites (WPCs) have recently introduced capped decking to their product lines. These new materials have begun to take market share from the previous generation of uncapped products that possessed a homogenous composition throughout the thickness of their cross-section. These capped offerings have been introduced with claims that the...

Walheim Troubleshoots GPC 3

NASA Image and Video Library

2011-07-11

S135-E-007351 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, watches as astronaut Chris Ferguson (out of frame at right) toggles switches on the overhead panel of the forward flight deck of the space shuttle Atlantis. The action came during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

Rearranging Deck Chairs in Dallas: Contextual Constraints and Within-District Resource Allocation in Urban Texas School Districts

ERIC Educational Resources Information Center

Baker, Bruce D.

2012-01-01

The goal of this study is to simultaneously explore resource allocation across schools within large urban school districts and across all schools within major metropolitan areas that include those urban districts in the state of Texas. This study uses a three-year panel, from 2005 to 2007, for Texas elementary schools in the Houston, Dallas,…

Evaluation of factors affecting resolution of shallow water bottom features

NASA Technical Reports Server (NTRS)

Mason, C. C.; Norris, D. R.; Browne, I. D.

1972-01-01

To ensure good aerial photography, the effects that factors such as submergence depth, sun angle, film and filter type, exposure, aircraft altitude, and polarization have on the photographic resolution of an underwater object must be determined. Various subjects were photographed, such as the deck of a small submersible, colored and gray scale panels, and natural bottom features. No underwater resolution target was used.

Modified creep and shrinkage prediction model B3 for serviceability limit state analysis of composite slabs

NASA Astrophysics Data System (ADS)

Gholamhoseini, Alireza

2016-03-01

Relatively little research has been reported on the time-dependent in-service behavior of composite concrete slabs with profiled steel decking as permanent formwork and little guidance is available for calculating long-term deflections. The drying shrinkage profile through the thickness of a composite slab is greatly affected by the impermeable steel deck at the slab soffit, and this has only recently been quantified. This paper presents the results of long-term laboratory tests on composite slabs subjected to both drying shrinkage and sustained loads. Based on laboratory measurements, a design model for the shrinkage strain profile through the thickness of a slab is proposed. The design model is based on some modifications to an existing creep and shrinkage prediction model B3. In addition, an analytical model is developed to calculate the time-dependent deflection of composite slabs taking into account the time-dependent effects of creep and shrinkage. The calculated deflections are shown to be in good agreement with the experimental measurements.

Development of Specifications for Engineered Cementitious Composites for Use in Bridge Deck Overlays

DOT National Transportation Integrated Search

2016-02-01

Engineered cementitious composite (ECC) material is a high strength, fiber-reinforced, ductile mortar mixture that can exhibit tensile strains of up to 5%. ECC has a dense matrix, giving the material exceptional durability characteristics. The durabi...

Reduction of Biomechanical and Welding Fume Exposures in Stud Welding.

PubMed

Fethke, Nathan B; Peters, Thomas M; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A

2016-04-01

The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18 min) when using conventional methods were high (18.2 mg m(-3) for bare beam; 65.7 mg m(-3) for through deck), with estimated mass concentrations of iron (7.8 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), zinc (0.2 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), and manganese (0.9 mg m(-3) for bare beam; 1.5 mg m(-3) for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17 nm) through deck conditions (34±34 nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure levels during stud welding simulations, but further development is needed before field deployment is possible. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Reduction of Biomechanical and Welding Fume Exposures in Stud Welding

PubMed Central

Fethke, Nathan B.; Peters, Thomas M.; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A.

2016-01-01

The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18min) when using conventional methods were high (18.2mg m−3 for bare beam; 65.7mg m−3 for through deck), with estimated mass concentrations of iron (7.8mg m−3 for bare beam; 15.8mg m−3 for through deck), zinc (0.2mg m−3 for bare beam; 15.8mg m−3 for through deck), and manganese (0.9mg m−3 for bare beam; 1.5mg m−3 for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17nm) through deck conditions (34±34nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure levels during stud welding simulations, but further development is needed before field deployment is possible. PMID:26602453

A Flight Deck Perspective of Self-Separation

NASA Technical Reports Server (NTRS)

Lozito, Sandra; Rosekind, Mark (Technical Monitor)

1997-01-01

I will be participating on a Free Flight Human Factors Panel at the Ninth International Symposium on Aviation Psychology in Columbus, Ohio. My representation is related to the work that our group has conducted on flight deck issues associate with free flight. Our group completed a full-mission simulation study investigating procedural issues associated with airborne self-separation. Ten crews flew eight scenarios each in the B747-400 simulator at Ames. Each scenario had a representation of different conflict geometries with intruder aircraft. New alerting logic was created and integrated into the simulator to enable self-separation. In addition, new display features were created to help provide for enhanced information to the flight crew about relevant aircraft, The participants were asked to coordinate maneuvers for self-separation with the intruder aircraft. Data analyses for the many of the crew procedures have been completed.

Highly accelerated lifetime for externally applied bond critical fiber-reinforced polymer (FRP) infrastructure materials : [summary].

DOT National Transportation Integrated Search

2014-03-01

The Florida Department of Transportation (FDOT) uses fiber-reinforced polymer (FRP) composites to repair bridges and strengthen bridge decks. Proven mechanical characteristics make FRP composites cost-effective in extending the life span of bridges o...

Glass/Epoxy Door Panel for Automobiles

NASA Technical Reports Server (NTRS)

Bauer, J. L. JR.

1985-01-01

Lightweight panel cost-effective. Integrally-molded intrusion strap key feature of composite outer door panel. Strap replaces bulky and heavy steel instrusion beam of conventional door. Standard steel inner panel used for demonstration purposes. Door redesigned to exploit advantages of composite outer panel thinner. Outer panel for automobilie door, made of glass/epoxy composite material, lighter than conventional steel door panel, meets same strength requirements, and less expensive.

Implementing and testing a panel-based method for modeling acoustic scattering from CFD input

NASA Astrophysics Data System (ADS)

Swift, S. Hales

Exposure of sailors to high levels of noise in the aircraft carrier deck environment is a problem that has serious human and economic consequences. A variety of approaches to quieting exhausting jets from high-performance aircraft are undergoing development. However, testing of noise abatement solutions at full-scale may be prohibitively costly when many possible nozzle treatments are under consideration. A relatively efficient and accurate means of predicting the noise levels resulting from engine-quieting technologies at personnel locations is needed. This is complicated by the need to model both the direct and the scattered sound field in order to determine the resultant spectrum and levels. While the direct sound field may be obtained using CFD plus surface integral methods such as the Ffowcs-Williams Hawkings method, the scattered sound field is complicated by its dependence on the geometry of the scattering surface--the aircraft carrier deck, aircraft control surfaces and other nearby structures. In this work, a time-domain boundary element method, or TD-BEM, (sometimes referred to in terms of source panels) is proposed and developed that takes advantage of and offers beneficial effects for the substantial planar components of the aircraft carrier deck environment and uses pressure gradients as its input. This method is applied to and compared with analytical results for planar surfaces, corners and spherical surfaces using an analytic point source as input. The method can also accept input from CFD data on an acoustic data surface by using the G1A pressure gradient formulation to obtain pressure gradients on the surface from the flow variables contained on the acoustic data surface. The method is also applied to a planar scattering surface characteristic of an aircraft carrier flight deck with an acoustic data surface from a supersonic jet large eddy simulation, or LES, as input to the scattering model. In this way, the process for modeling the complete sound field (assuming the availability of an acoustic data surface from a time-realized numerical simulation of the jet flow field) is outlined for a realistic group of source location, scattering surface location and observer locations. The method was able to successfully model planar cases, corners and spheres with a level of error that is low enough for some engineering purposes. Significant benefits were realized for fully planar surfaces including high parallelizability and avoidance of interaction between portions of the paneled boundary. When the jet large eddy simulation case was considered the method was able to capture a substantial portion of the spectrum including the peak frequency region and a majority of the spectral energy with good fidelity.

Lightweight composites for modular panelized construction

NASA Astrophysics Data System (ADS)

Vaidya, Amol S.

Rapid advances in construction materials technology have enabled civil engineers to achieve impressive gains in the safety, economy, and functionality of structures built to serve the common needs of society. Modular building systems is a fast-growing modern, form of construction gaining recognition for its increased efficiency and ability to apply modern technology to the needs of the market place. In the modular construction technique, a single structural panel can perform a number of functions such as providing thermal insulation, vibration damping, and structural strength. These multifunctional panels can be prefabricated in a manufacturing facility and then transferred to the construction site. A system that uses prefabricated panels for construction is called a "panelized construction system". This study focuses on the development of pre-cast, lightweight, multifunctional sandwich composite panels to be used for panelized construction. Two thermoplastic composite panels are proposed in this study, namely Composite Structural Insulated Panels (CSIPs) for exterior walls, floors and roofs, and Open Core Sandwich composite for multifunctional interior walls of a structure. Special manufacturing techniques are developed for manufacturing these panels. The structural behavior of these panels is analyzed based on various building design codes. Detailed descriptions of the design, cost analysis, manufacturing, finite element modeling and structural testing of these proposed panels are included in this study in the of form five peer-reviewed journal articles. The structural testing of the proposed panels involved in this study included flexural testing, axial compression testing, and low and high velocity impact testing. Based on the current study, the proposed CSIP wall and floor panels were found satisfactory, based on building design codes ASCE-7-05 and ACI-318-05. Joining techniques are proposed in this study for connecting the precast panels on the construction site. Keywords: Modular panelized construction, sandwich composites, composite structural insulated panels (CSIPs).

STS-47 Pilot Brown on OV-105's flight deck ten minutes after SSME cutoff

NASA Technical Reports Server (NTRS)

1992-01-01

STS-47 Pilot Curtis L. Brown, Jr, is photographed at Endeavour's, Orbiter Vehicle (OV) 105's, pilot station about ten minutes after space shuttle main engine (SSME) cutoff on launch day. Brown smiles from inside the launch and entry suit (LES) and launch and entry helmet (LEH). In the background are the flight mirror assembly silhouetted against forward window W5, control panels, and a checklist.

58. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE, 1884, Ms. 14, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

58. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE, 1884, Ms. 14, E 6.5 mi. to McLeod, 4.5 miles S on McLeod-Shuqualak road. Mahorner's bridge (1884). Lower panel point, west span. View is at right-angles to the bridge and from below deck level. show pin connection, floor beams, and stringers. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

Progress in Military Airlift (Les Progres Realises dans le Domaine du Transport Aerien Militaire)

DTIC Science & Technology

1991-05-01

transformation of the flight deck, with both visible and concealed changes. This crew/ airplane interface modification has resulted in an evolution of ...300 ADVISORY GROUP FOR AEROSPACE RESEARCH & DEVELOPMENT 7 RUE ANCELLE 92200 NEUILLY SUR SEINE FRANCE AGARD ADVISORY REPOW 300 Technical Evaluation...Advisory Report was prepared at the request of the ’ Flight Mechanics Panel of AGARD. _ North Atlantic Treaty Organization Organisation du Trait de

Pilot Fullerton reviews FDF and TAGS printout on forward flight deck

NASA Image and Video Library

1982-03-30

STS003-23-180 (22-30 March 1982) --- Astronaut Gordon Fullerton, STS-3 pilot, wearing communications kit assembly (ASSY) mini-headset (HDST), reviews flight data file (FDF) checklist and text and graphics system (TAGS) printout (ticker tape) while in pilots ejection seat (S2). Pilot station control panels F4, F7, F8, O3, window shade, and portable oxygen system (POS) assy appear in view. Photo credit: NASA

Currie at RMS controls on the aft flight deck

NASA Image and Video Library

1998-12-05

S88-E-5010 (12-05-98) --- Operating at a control panel on Endeavour's aft flight deck, astronaut Nancy J. Currie works with the robot arm prior to mating the 12.8-ton Unity connecting module to Endeavour's docking system. The mating took place on late afternoon of Dec. 5. A nearby monitor provides a view of the remote manipulator system's (RMS) movements in the cargo bay. The feat marked an important step in assembling the new International Space Station. Manipulating the shuttle's 50-foot-long robot arm, Currie placed Unity just inches above the extended outer ring on Endeavour's docking mechanism, enabling Robert D. Cabana, mission commander to fire downward maneuvering jets, locking the shuttle's docking system to one of two Pressurized Mating Adapters (PMA) attached to Unity. The mating occurred at 5:45 p.m. Central time, as Endeavour sailed over eastern China.

Characterization of weathered wood-plastic composite surfaces using FTIR spectroscopy, contact angle, and XPS

Treesearch

Nicole M. Stark; Laurent M. Matuana

2007-01-01

Much of the current growth of wood-plastic composites (WPCs) is due to increased penetration into the decking market; therefore it has become imperative to understand the durability of WPCs in outdoor applications. In this study, wood flour filled high-density polyethylene (HDPE) composites were manufactured through either injection molding or extrusion. A set of...

Simplified Calculation Model and Experimental Study of Latticed Concrete-Gypsum Composite Panels

PubMed Central

Jiang, Nan; Ma, Shaochun

2015-01-01

In order to address the performance complexity of the various constituent materials of (dense-column) latticed concrete-gypsum composite panels and the difficulty in the determination of the various elastic constants, this paper presented a detailed structural analysis of the (dense-column) latticed concrete-gypsum composite panel and proposed a feasible technical solution to simplified calculation. In conformity with mechanical rules, a typical panel element was selected and divided into two homogenous composite sub-elements and a secondary homogenous element, respectively for solution, thus establishing an equivalence of the composite panel to a simple homogenous panel and obtaining the effective formulas for calculating the various elastic constants. Finally, the calculation results and the experimental results were compared, which revealed that the calculation method was correct and reliable and could meet the calculation needs of practical engineering and provide a theoretical basis for simplified calculation for studies on composite panel elements and structures as well as a reference for calculations of other panels. PMID:28793631

Simplified Calculation Model and Experimental Study of Latticed Concrete-Gypsum Composite Panels.

PubMed

Jiang, Nan; Ma, Shaochun

2015-10-27

In order to address the performance complexity of the various constituent materials of (dense-column) latticed concrete-gypsum composite panels and the difficulty in the determination of the various elastic constants, this paper presented a detailed structural analysis of the (dense-column) latticed concrete-gypsum composite panel and proposed a feasible technical solution to simplified calculation. In conformity with mechanical rules, a typical panel element was selected and divided into two homogenous composite sub-elements and a secondary homogenous element, respectively for solution, thus establishing an equivalence of the composite panel to a simple homogenous panel and obtaining the effective formulas for calculating the various elastic constants. Finally, the calculation results and the experimental results were compared, which revealed that the calculation method was correct and reliable and could meet the calculation needs of practical engineering and provide a theoretical basis for simplified calculation for studies on composite panel elements and structures as well as a reference for calculations of other panels.

Optimization of composite sandwich cover panels subjected to compressive loadings

NASA Technical Reports Server (NTRS)

Cruz, Juan R.

1991-01-01

An analysis and design method is presented for the design of composite sandwich cover panels that includes transverse shear effects and damage tolerance considerations. This method is incorporated into an optimization program called SANDOP (SANDwich OPtimization). SANDOP is used in the present study to design optimized composite sandwich cover panels for transport aircraft wing applications as a demonstration of its capabilities. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to identical constraints. Results indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and plus or minus 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density.

Fabrication and testing of fire resistant graphite composite panels

NASA Technical Reports Server (NTRS)

Roper, W. D.

1986-01-01

Eight different graphite composite panels were fabricated using four different resin matrices. The resin matrices included Hercules 71775, a blend of vinylpolystyrpyridine and bismaleimide, H795, a bismaleimide, Cycom 6162, a phenolic, and PSP 6022m, a polystyrylpyridine. Graphite panels were fabricated using fabric or unidirectional tape. Described are the processes for preparing these panels and some of their mechanical, thermal and flammability properties. Panel properties are compared with state-of-the-art epoxy fiberglass composite panels.

STS-26 Commander Hauck in fixed based (FB) shuttle mission simulator (SMS)

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing comunications kit assembly headset, checks control panel data while seated in the commanders seat on forward flight deck. A flight data file (FDF) notebook rests on his lap. A portable computer (laptop) is positioned on the center console. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

Plug Repairs of Marine Glass Fiber / Vinyl Ester Laminates Subjected to Uniaxial Tension

DTIC Science & Technology

2009-06-01

Material characteristics of glass fiber / vinyl ester composites used in naval surface ships 1.1.1.2 Construction of surface ship hulls with FRP...Piping - Ventilation ducts - Deck gratings 1.1.1.1 Material characteristics of glass fiber / vinyl ester composites used in naval surface ships The...that polysester-based composites do [15, 24]. Typical processing methods for vinyl ester composites are hand lay-up, Resin Transfer Molding (RTM

Solar reflection panels

DOEpatents

Diver, Jr., Richard B.; Grossman, James W [Albuquerque, NM; Reshetnik, Michael [Boulder, CO

2006-07-18

A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

Coating WPC's using co-extrusion to improve durability

Treesearch

Nicole M. Stark; Laurent M. Matuana

2007-01-01

Wood-plastic composites (WPCs) have been gaining market share in the residential construction industry as lumber for decking, roof tiles, and siding. The durability of these materials in exterior environments is just beginning to be understood. Current research suggests that controlling moisture absorption by the composite is key to improving durability. Methods to...

Outdoor durability of wood-polymer composites

Treesearch

N. M. Stark; D. J. Gardner

2008-01-01

Wood-plastic composite (WPC) lumber is promoted as a low-maintenance, high-durability product (Clemons, 2002). However, after a decade of exterior use in the construction industry, questions have arisen regarding durability. These questions are based on documented evidence of failures in the field of WPC decking products due to such impacts as polymer degradation (...

Optimization of composite sandwich cover panels subjected to compressive loadings

NASA Technical Reports Server (NTRS)

Cruz, Juan R.

1991-01-01

An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

A Preliminary Experimental Study on Vibration Responses of Foamed Concrete Composite Slabs

NASA Astrophysics Data System (ADS)

Rum, R. H. M.; Jaini, Z. M.; Ghaffar, N. H. Abd; Rahman, N. Abd

2017-11-01

In recent years, composite slab has received utmost demand as a floor system in the construction industry. The composite slab is an economical type of structure and able to accelerate the construction process. Basically, the composite slab can be casting by using a combination of corrugated steel deck and normal concrete in which selfweight represents a very large proportion of the total action. Therefore, foamed concrete become an attractive alternative to be utilized as a replacement of normal concrete. However, foamed concrete has high flexibility due to the presence of large amount of air-void and low modulus elasticity. It may result in vibration responses being greater. Hence, this experimental study investigates the vibration responses of composite slab made of corrugated steel deck and foamed concrete. The specimens were prepared with dimension of 750mm width, 1600mm length and 125mm thickness. The hammer-impact test was conducted to obtain the acceleration-time history. The analysis revealed that the first natural frequency is around 27.97 Hz to 40.94 Hz, while the maximum acceleration reaches 1.31 m/s2 to 1.88 m/s2. The first mode shape depicts normal pattern and favourable agreement of deformation.

Tensile strength of composite sheets with unidirectional stringers and crack-like damage

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1984-01-01

The damage tolerance characteristics of metal tension panels with riveted and bonded stringers are well known. The stringers arrest unstable cracks and retard propagation of fatigue cracks. Residual strengths and fatigue lives are considerably greater than those of unstiffened or integrally stiffened sheets. The damage tolerance of composite sheets with bonded composite stringers loaded in tension was determined. Cracks in composites do not readily propagate in fatigue, at least not through fibers. Moreover, the residual strength of notched composites is sometimes even increased by fatigue loading. Therefore, the residual strength aspect of damage tolerance, and not fatigue crack propagation, was investigated. About 50 graphite/epoxy composite panels were made with two sheet layups and several stringer configurations. Crack-like slots were cut in the middle of the panels to simulate damage. The panels were instrumented and monotonically loaded in tension to failure. The tests indicate that the composite panels have considerable damage tolerance, much like metal panels. The stringers arrested cracks that ran from the crack-like slots, and the residual strengths were considerably greater than those of unstiffened composite sheets. A stress intensity factor analysis was developed to predict the failing strains of the stiffened panels. Using the analysis, a single design curve was produced for composite sheets with bonded stringers of any configuration.

STS-44 Atlantis, OV-104, crewmembers participate in FB-SMS training at JSC

NASA Technical Reports Server (NTRS)

1991-01-01

STS-44 Atlantis, Orbiter Vehicle (OV) 104, Commander Frederick D. Gregory (left) and Pilot Terence T. Henricks, positioned at their appointed stations on the forward flight deck, are joined by Mission Specialist (MS) F. Story Musgrave (center) and MS James S. Voss (standing). The crewmembers are participating in a flight simulation in the Fixed Base (FB) Shuttle Mission Simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. A maze of panel switches appear overhead and in the background.

-V2 plane on the Hubble Space Telescope

NASA Image and Video Library

2002-03-03

STS109-E-5104 (3 March 2002) --- The Hubble Space Telescope is seen in the cargo bay of the Space Shuttle Columbia. Each present set of solar array panels will be replaced during one of the space walks planned for the coming week. The crew aimed various cameras, including the digital still camera used for this frame, out the shuttle's aft flight deck windows to take a series of survey type photos, the first close-up images of the telescope since December of 1999.

-V2 plane on the Hubble Space Telescope

NASA Image and Video Library

2002-03-03

STS109-E-5102 (3 March 2002) --- The Hubble Space Telescope is seen in the cargo bay of the Space Shuttle Columbia. Each present set of solar array panels will be replaced during one of the space walks planned for the coming week. The crew aimed various cameras, including the digital still camera used for this frame, out the shuttle's aft flight deck windows to take a series of survey type photos, the first close-up images of the telescope since December of 1999.

STS-109 MS Newman and Massimino in airlock after EVA

NASA Image and Video Library

2002-03-05

STS109-326-031 (5 March 2002) --- The broad smiles of astronauts Michael J. Massimino (left) and James H. Newman reflect the success of their just-completed lengthy space walk designed to finish the replacement of the solar arrays on the Hubble Space Telescope (HST). A day earlier, two other astronauts replaced one of sets of solar panels. The two are in the process of doffing their extravehicular mobility unit (EMU) space suits on the mid deck of the Space Shuttle Columbia.

STS-37 Gamma Ray Observatory (GRO) grappled by RMS

NASA Image and Video Library

1991-04-07

Backdropped against the Earth's surface, the Gamma Ray Observatory (GRO) with its solar array (SA) panels deployed is grappled by the remote manipulator system (RMS) during STS-37 systems checkout. GRO's four complement instruments are visible: the Energetic Gamma Ray Experiment Telescope (EGRET) (at the bottom); the Imaging Compton Telescope (COMPTEL) (center); the Oriented Scintillation Spectrometer Experiment (OSSE) (top); and Burst and Transient Source Experiment (BATSE) (on four corners). The view was taken by STS-37 crew through an aft flight deck overhead window.

Progressive Failure Analysis of Composite Stiffened Panels

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Yarrington, Phillip W.; Collier, Craig S.; Arnold, Steven M.

2006-01-01

A new progressive failure analysis capability for stiffened composite panels has been developed based on the combination of the HyperSizer stiffened panel design/analysis/optimization software with the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC). MAC/GMC discretizes a composite material s microstructure into a number of subvolumes and solves for the stress and strain state in each while providing the homogenized composite properties as well. As a result, local failure criteria may be employed to predict local subvolume failure and the effects of these local failures on the overall composite response. When combined with HyperSizer, MAC/GMC is employed to represent the ply level composite material response within the laminates that constitute a stiffened panel. The effects of local subvolume failures can then be tracked as loading on the stiffened panel progresses. Sample progressive failure results are presented at both the composite laminate and the composite stiffened panel levels. Deformation and failure model predictions are compared with experimental data from the World Wide Failure Exercise for AS4/3501-6 graphite/epoxy laminates.

Combined-load buckling behavior of metal-matrix composite sandwich panels under different thermal environments

NASA Technical Reports Server (NTRS)

Ko, William L.; Jackson, Raymond H.

1991-01-01

Combined compressive and shear buckling analysis was conducted on flat rectangular sandwich panels with the consideration of transverse shear effects of the core. The sandwich panel is fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that the square panel has the highest combined load buckling strength, and that the buckling strength decreases sharply with the increases of both temperature and panel aspect ratio. The effect of layup (fiber orientation) on the buckling strength of the panels was studied in detail. The metal matrix composite sandwich panel was much more efficient than the sandwich panel with nonreinforced face sheets and had the same specific weight.

Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

NASA Astrophysics Data System (ADS)

Flaga, Kazimierz; Furtak, Kazimierz

2015-03-01

Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life). The most commonly found in practice are composite girder bridges, particularly in highway bridges of small and medium spans, but the spans may reach over 200 m. In larger spans steel truss girders are applied. Bridge composite structures are also employed in cable-stayed bridge decks of the main girder spans of the order of 600, 800 m. The aim of the article is to present the cionstruction process and strength analysis problems concerning of this type of structures. Much attention is paid to the design and calculation of the shear connectors characteristic for the discussed objects. The authors focused mainly on the issues of single composite structures. The effect of assembly states on the stresses and strains in composite members are highlighted. A separate part of problems is devoted to the influence of rheological factors, i.e. concrete shrinkage and creep, as well as thermal factors on the stresses and strains and redistribution of internal forces.

Characterization of bridge deck runoff.

DOT National Transportation Integrated Search

2015-03-01

In this study, time-weighted composite samples of bridge runoff and hourly traffic data were collected at four sampling : locations in Nebraska. Total suspended solids (TSS) and hexane extractable material (HEM) had the highest concentrations : durin...

Characterization of stormwater runoff from bridge decks in eastern Massachusetts, 2014–16

USGS Publications Warehouse

Smith, Kirk P.; Sorenson, Jason R.; Granato, Gregory E.

2018-05-02

The quality of stormwater runoff from bridge decks (hereafter referred to as “bridge-deck runoff”) was characterized in a field study from August 2014 through August 2016 in which concentrations of suspended sediment (SS) and total nutrients were monitored. These new data were collected to supplement existing highway-runoff data collected in Massachusetts which were deficient in bridge-deck runoff concentration data. Monitoring stations were installed at three bridges maintained by the Massachusetts Department of Transportation in eastern Massachusetts (State Route 2A in the city of Boston, Interstate 90 in the town of Weston, and State Route 20 near Quinsigamond Village in the city of Worcester). The bridges had annual average daily traffic volumes from 21,200 to 124,000 vehicles per day; the land use surrounding the monitoring stations was 25 to 67 percent impervious.Automatic-monitoring techniques were used to collect more than 160 flow-proportional composite samples of bridge-deck runoff. Samples were analyzed for concentrations of SS, loss on ignition of suspended solids (LOI), particulate carbon (PC), total phosphorus (TP), total dissolved nitrogen (DN), and particulate nitrogen (PN). The distribution of particle size of SS also was determined for composite samples. Samples of bridge-deck runoff were collected year round during rain, mixed precipitation, and snowmelt runoff and with different dry antecedent periods throughout the 2-year sampling period.At the three bridge-deck-monitoring stations, median concentrations of SS in composite samples of bridge-deck runoff ranged from 1,490 to 2,020 milligrams per liter (mg/L); however, the range of SS in individual composites was vast at 44 to 142,000 mg/L. Median concentrations of SS were similar in composite samples collected from the State Route 2A and Interstate 90 bridge (2,010 and 2,020 mg/L, respectively), and lowest at the State Route 20 bridge (1,490 mg/L). Concentrations of coarse sediment (greater than 0.25 millimeters in diameter) dominated the SS matrix by more than an order of magnitude. Concentrations of LOI and PC in composite samples ranged from 15 to 1,740 mg/L and 6.68 to 1,360 mg/L, respectively, and generally represented less than 10 and 3 percent of the median mass of SS, respectively. Concentrations of TP in composite samples ranged from 0.09 to 7.02 mg/L; median concentrations of TP ranged from 0.505 to 0.69 mg/L and were highest on the bridge on State Route 2A in Boston. Concentrations of total nitrogen (TN) (sum DN and PN) in composite samples were variable (0.36 to 29 mg/L). Median DN (0.64 to 0.90 mg/L) concentrations generally represented about 40 percent of the TN concentration at each bridge and were similar to annual volume-weighted mean concentrations of nitrogen in precipitation in Massachusetts.Nonparametric statistical methods were used to test for differences between sample constituent concentrations among the three bridges. These results indicated that there are no statistically significant differences for concentrations of SS, LOI, PC, and TP among the three bridges (one-way analysis of variance test on rank-transformed data, 95-percent confidence level). Test results for concentrations of TN in composite samples indicated that concentrations of TN collected on State Route 20 near Quinsigamond Village were significantly higher than those concentrations collected on State Route 2A in Boston and Interstate 90 near Weston. Median concentrations of TN were about 93 and 55 percent lower at State Route 2A and at Interstate 90, respectively, compared to the median concentrations of TN at State Route 20.Samples of sediment were collected from five fixed locations on each bridge on three occasions during dry weather to calculate semiquantitative distributions of sediment yields on the bridge surface relative to the monitoring location. Mean yields of bridge-deck sediment during this study for State Route 2A in Boston, Interstate 90 near Weston, and State Route 20 near Quinsigamond Village were 1,500, 250, and 5,700 pounds per curb-mile, respectively. Sediment yields at each sampling location varied widely (26 to 25,000 pounds per curb-mile) but were similar to yields reported elsewhere in Massachusetts and the United States. Yields calculated for each sampling location indicated that the sediment was not evenly distributed across each bridge in this study for plausible reasons such as bridge slope, vehicular tracking, and bridge deterioration.Bridge-deck sediment quality was largely affected by the distribution of sediment particle size. Concentrations of TP in the fine sediment-size fraction (less than 0.0625 millimeter in diameter) of samples of bridge-deck sediment were about 6 times greater than in the coarse size fraction. Concentrations for many total-recoverable metals were 2 to 17 times greater in the fine size fraction compared to concentrations in the coarse size fraction (greater than or equal to 0.25 millimeter in diameter), and concentrations of total-recoverable copper and lead in the fine size fraction were 2 to 65 times higher compared to concentrations in the intermediate (greater than or equal to 0.0625 to 0.25 millimeter in diameter) or the coarse size fraction. However, the proportion of sediment particles less than 0.0625 millimeter in diameter in composite samples of bridge-deck runoff was small (median values range from 4 to 8 percent at each bridge) compared to the larger sediment particle-size mass. As a result, more than 50 percent of the sediment-associated TP, aluminum, chromium, manganese, and nickel was estimated to be associated with the coarse size fraction of the SS load. In contrast, about 95 percent of the estimated sediment-associated copper concentration was associated with the fine size fraction of the SS load.Version 1.0.2 of the Stochastic Empirical Loading and Dilution Model was used to simulate long-term (29–30-year) concentrations and annual yields of SS, TP, and TN in bridge-deck runoff and in discharges from a hypothetical stormwater treatment best-management practice structure. Three methods (traditional statistics, robust statistics, and L-moments) were used to calculate statistics for stochastic simulations because the high variability in measured concentration values during the field study resulted in extreme simulated concentrations. Statistics of each dataset, including the average, standard deviation, and skew of the common (base 10) logarithms, for each of the three bridges, and for a lumped dataset, were calculated and used for simulations; statistics representing the median of statistics calculated for the three bridges also were used for simulations. These median statistics were selected for the interpretive simulations so that the simulations could be used to estimate concentrations and yields from other, unmonitored bridges in Massachusetts. Comparisons of the standard and robust statistics indicated that simulation results with either method would be similar, which indicated that the large variability in simulated results was not caused by a few outliers. Comparison to statistics calculated by the L-moments methods indicated that L-moments do not produce extreme concentrations; however, they also do not produce results that represent the bulk of concentration data.The runoff-quality risk analysis indicated that bridge-deck runoff would exceed discharge standards commonly used for large, advanced wastewater treatment plants, but that commonly used stormwater best-management practices may reduce the percentage of exceedances by one-half. Results of simulations indicated that long-term average yields of TN, TP, and SS may be about 21.4, 6.44, and 40,600 pounds per acre per year, respectively. These yields are about 1.3, 3.4, and 16 times simulated ultra-urban highway yields in Massachusetts; however, simulations indicated that use of a best-management practice structure to treat bridge-deck runoff may reduce discharge yields to about 10, 2.8, and 4,300, pounds per acre per year, respectively.

Predicting the flexure response of wood-plastic composites from uni-axial and shear data using a finite-element model

Treesearch

Scott E. Hamel; John C. Hermanson; Steven M. Cramer

2014-01-01

Wood-plastic composites (WPCs), commonly used in residential decks and railings, exhibit mechanical behavior that is bimodal, anisotropic, and nonlinear viscoelastic. They exhibit different stress-strain responses to tension and compression, both of which are nonlinear. Their mechanical properties vary with respect to extrusion direction, their deformation under...

Co-extrusion of WPCs with a clear cap layer to improve color stability

Treesearch

Nicole M. Stark; Laurent M. Matuana

2009-01-01

Wood-plastic composites (WPCs) have been gaining market share in residential construction applications such as lumber for decking, roof tiles, and siding. The durability of these materials in exterior environments is just beginning to be understood. Current research suggests that controlling moisture absorption by the composite is key to improving durability. Methods...

Field and Laboratory Decay Evaluations of wood-plastic Composites

Treesearch

Rebecca E. Ibach; Marek Gnatowski; Grace Sun

2013-01-01

Experimental wood–plastic composites (WPCs) were made so that they matched the manufacturing process, dimensions, and water absorption of some commercial decking boards. WPC samples from selected formulations were divided into two identical groups. The first group was exposed in exterior conditions in Vancouver, British Columbia, and Hilo, Hawaii, at sun and shadow...

Analysis/design of strip reinforced random composites (strip hybrids)

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Sinclair, J. H.

1978-01-01

Advanced analysis methods and composite mechanics were applied to a strip-reinforced random composite square panel with fixed ends to illustrate the use of these methods for the a priori assessment of the composite panel when subjected to complex loading conditions. The panel was assumed to be of E-glass random composite. The strips were assumed to be of three advanced unidirectional composites to cover a range of low, intermediate, and high modulus stiffness. The panels were assumed to be subjected to complex loadings to assess their adequacy as load-carrying members in auto body, aircraft engine nacelle and windmill blade applications. The results show that strip hybrid panels can be several times more structurally efficient than the random composite base materials. Some of the results are presented in graphical form and procedures are described for use of these graphs as guides for preliminary design of strip hybrids.

Composite panels made with biofiber or office wastepaper bonded with thermoplastic and/or thermosetting resin

Treesearch

James H. Muehl; Andrzej M. Krzysik; Poo Chow

2004-01-01

The purpose of this study was to evaluate two groups of composite panels made from two types of underutilized natural fiber sources, kenaf bast fiber and office wastepaper, for their suitability in composite panels. All panels were made with 5% thermosetting phenol-formaldehyde (PF) resin and 1.5% wax. Also, an additional 10% polypropylene (PP) thermoplastic resin was...

77 FR 44683 - Notice of Investigation Regarding Termination of Certification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... Investigation Regarding Termination of Certification TA-W-80,308, Roseburg Forest Products, Composite Panel... Products, Composite Panel Division, Including On-Site Leased Workers of Robert Half, Russellville, SC. On... Assistance (TAA) applicable to workers and former workers of Roseburg Forest Products, Composite Panel...

Design, testing, and damage tolerance study of bonded stiffened composite wing cover panels

NASA Technical Reports Server (NTRS)

Madan, Ram C.; Sutton, Jason O.

1988-01-01

Results are presented from the application of damage tolerance criteria for composite panels to multistringer composite wing cover panels developed under NASA's Composite Transport Wing Technology Development contract. This conceptual wing design integrated aeroelastic stiffness constraints with an enhanced damage tolerance material system, in order to yield optimized producibility and structural performance. Damage tolerance was demonstrated in a test program using full-sized cover panel subcomponents; panel skins were impacted at midbay between stiffeners, directly over a stiffener, and over the stiffener flange edge. None of the impacts produced visible damage. NASTRAN analyses were performed to simulate NDI-detected invisible damage.

Damage assessment and residual compression strength of thick composite plates with through-the-thickness reinforcements

NASA Technical Reports Server (NTRS)

Smith, Barry T.

1990-01-01

Damage in composite materials was studied with through-the-thickness reinforcements. As a first step it was necessary to develop new ultrasonic imaging technology to better assess internal damage of the composite. A useful ultrasonic imaging technique was successfully developed to assess the internal damage of composite panels. The ultrasonic technique accurately determines the size of the internal damage. It was found that the ultrasonic imaging technique was better able to assess the damage in a composite panel with through-the-thickness reinforcements than by destructively sectioning the specimen and visual inspection under a microscope. Five composite compression-after-impact panels were tested. The compression-after-impact strength of the panels with the through-the-thickness reinforcements was almost twice that of the comparable panel without through-the-thickness reinforcement.

Composite View from Phoenix Lander

NASA Image and Video Library

2009-07-02

This mosaic of images from the Surface Stereo Imager camera on NASA Phoenix Mars Lander shows several trenches dug by Phoenix, plus a corner of the spacecraft deck and the Martian arctic plain stretching to the horizon.

Behavior of composite sandwich panels with several core designs at different impact velocities

NASA Astrophysics Data System (ADS)

Jiga, Gabriel; Stamin, Ştefan; Dinu, Gabriela

2018-02-01

A sandwich composite represents a special class of composite materials that is manufactured by bonding two thin but stiff faces to a low density and low strength but thick core. The distance between the skins given by the core increases the flexural modulus of the panel with a low mass increase, producing an efficient structure able to resist at flexural and buckling loads. The strength of sandwich panels depends on the size of the panel, skins material and number or density of the cells within it. Sandwich composites are used widely in several industries, such as aerospace, automotive, medical and leisure industries. The behavior of composite sandwich panels with different core designs under different impact velocities are analyzed in this paper by numerical simulations performed on sandwich panels. The modeling was done in ANSYS and the analysis was performed through LS-DYNA.

Thermal and Mechanical Buckling Analysis of Hypersonic Aircraft Hat-Stiffened Panels With Varying Face Sheet Geometry and Fiber Orientation

NASA Technical Reports Server (NTRS)

Ko, William L.

1996-01-01

Mechanical and thermal buckling behavior of monolithic and metal-matrix composite hat-stiffened panels were investigated. The panels have three types of face-sheet geometry: Flat face sheet, microdented face sheet, and microbulged face sheet. The metal-matrix composite panels have three types of face-sheet layups, each of which is combined with various types of hat composite layups. Finite-element method was used in the eigenvalue extractions for both mechanical and thermal buckling. The thermal buckling analysis required both eigenvalue and material property iterations. Graphical methods of the dual iterations are shown. The mechanical and thermal buckling strengths of the hat-stiffened panels with different face-sheet geometry are compared. It was found that by just microdenting or microbulging of the face sheet, the axial, shear, and thermal buckling strengths of both types of hat-stiffened panels could be enhanced considerably. This effect is more conspicuous for the monolithic panels. For the metal-matrix composite panels, the effect of fiber orientations on the panel buckling strengths was investigated in great detail, and various composite layup combinations offering, high panel buckling strengths are presented. The axial buckling strength of the metal-matrix panel was sensitive to the change of hat fiber orientation. However, the lateral, shear, and thermal buckling strengths were insensitive to the change of hat fiber orientation.

STS-56 Commander Cameron uses SAREX on OV-103's aft flight deck

NASA Technical Reports Server (NTRS)

1993-01-01

STS-56 Commander Kenneth Cameron, wearing headset and headband equipped with penlight flashlight, uses the Shuttle Amateur Radio Experiment II (SAREX-II) on the aft flight deck of Discovery, Orbiter Vehicle (OV) 103. Cameron, positioned just behind the pilots seat, talks to amateur radio operators on Earth via the SAREX equipment. SAREX cables and the interface module freefloat in front of the pilots seat. The SAREX scan converter (a white box) is seen just above Cameron's head attached to overhead panel O9. SAREX was established by NASA, the American Radio League/Amateur Radio Satellite Corporation and the JSC Amateur Radio Club to encourage public participation in the space program through a program to demonstrate the effectiveness of conducting short-wave radio transmissions between the Shuttle and ground-based radio operators at low-cost ground stations with amateur and digital techniques. As on several previous missions, SAREX was used on this flight as an educational opportunity

Development of the technology for the fabrication of reliable laminar from control panels

NASA Technical Reports Server (NTRS)

Meade, L. E.; Kays, A. O.; Ferrill, R. S.; Young, H. R.

1977-01-01

Materials were assessed and fabrication techniques were developed for use in the manufacture of wing surface materials compatible with the application of both aluminum alloys and nonmetallic composites. The concepts investigated included perforations and slots in the metallic test panels and microporosity and perforations in the composite test panels. Perforations were produced in the metallic test panels by the electron beam process and slots were developed by controlled gaps between the metal sheets. Microporosity was produced in the composite test panels by the resin bleed process, and perforations were produced by the fugitive fiber technique. Each of these concepts was fabricated into test panels, and air flow tests were conducted on the panels.

77 FR 17524 - Roseburg Forest Products, Composite Panels Division, Missoula, MT; Notice of Affirmative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,459] Roseburg Forest Products, Composite Panels Division, Missoula, MT; Notice of Affirmative Determination Regarding Application for... Assistance (TAA) applicable to workers and former workers of Roseburg Forest Products, Composite Panels...

77 FR 56870 - Notice of Continuation of Certification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-14

... [TA-W-80,308] Roseburg Forest Products, Composite Panel Division, Including On-Site Leased Workers of Robert Half, Orangeburg, SC [TA-W-80,308A] Roseburg Forest Products, Composite Panel Division, Including... (TAA) applicable to workers and former workers of Roseburg Forest Products, Composite Panel Division...

Postbuckling delamination of a stiffened composite panel using finite element methods

NASA Technical Reports Server (NTRS)

Natsiavas, S.; Babcock, C. D.; Knauss, W. G.

1987-01-01

A combined numerical and experimental study is carried out for the postbuckling behavior of a stiffened composite panel. The panel is rectangular and is subjected to static in-plane compression on two opposite edges to the collapse level. Nonlinear (large deflection) plate theory is employed, together with an experimentally based failure criterion. It is found that the stiffened composite panel can exhibit significant postbuckling strength.

Nonlinear flutter analysis of composite panels

NASA Astrophysics Data System (ADS)

An, Xiaomin; Wang, Yan

2018-05-01

Nonlinear panel flutter is an interesting subject of fluid-structure interaction. In this paper, nonlinear flutter characteristics of curved composite panels are studied in very low supersonic flow. The composite panel with geometric nonlinearity is modeled by a nonlinear finite element method; and the responses are computed by the nonlinear Newmark algorithm. An unsteady aerodynamic solver, which contains a flux splitting scheme and dual time marching technology, is employed in calculating the unsteady pressure of the motion of the panel. Based on a half-step staggered coupled solution, the aeroelastic responses of two composite panels with different radius of R = 5 and R = 2.5 are computed and compared with each other at different dynamic pressure for Ma = 1.05. The nonlinear flutter characteristics comprising limited cycle oscillations and chaos are analyzed and discussed.

77 FR 35061 - Roseburg Forest Products Composite Panels Division Missoula, Montana; Notice of Negative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,459] Roseburg Forest Products Composite Panels Division Missoula, Montana; Notice of Negative Determination on Reconsideration On March 14... for Reconsideration for the workers and former workers of Roseburg Forest Products, Composite Panels...

A Study of Damage Tolerance in Curved Composite Panels.

DTIC Science & Technology

1988-03-01

A198 617 A STUDY OF DAMAGE TOLERANCE IN CURVED COMPOSITE PANELS 1/2 I CNO O NGNERN BLNuE Hl(U) Ala FORCE INST OF TECH &IRIGHT-PATTERSON APR ON...OAL B PEAU OF STANOARDS- -T - % r . P.4 .% FILE CC R CDV OF DTIC MAR3 11988 *grr A STUDY OF DAMAGE TOLERANCE IN CURVED COMPOSITE PANELS THESIS...AFIT/GA/AA/88-.3 0 A STUDY OF DAMAGE TOLERANCE IN CURVED COMPOSITE PANELS THESIS - Brendan L. Wilder Captain, USAF S*2822 $$$*fltf$$*2*f$1fltf

Composite sandwich lattice structure

NASA Technical Reports Server (NTRS)

Rhodes, M. D. (Inventor); Mikulas, M. M., Jr.

1977-01-01

A lattice type structural panel is described. The panel utilizes the unidirectional character of filamentary epoxy impregnated composites. The panels are stiff lightweight structures for use in constructing space satellites and the like.

Exterior Decay of Wood-Plastic Composite Boards: Characterization and Magnetic Resonance Imaging

Treesearch

Rebecca Ibach; Grace Sun; Marek Gnatowski; Jessie Glaeser; Mathew Leung; John Haight

2016-01-01

Magnetic resonance imaging (MRI) was used to evaluate free water content and distribution in wood-plastic composite (WPC) materials decayed during exterior exposure near Hilo, Hawaii. Two segments of the same board blend were selected from 6 commercial decking boards that had fungal fruiting bodies. One of the two board segments was exposed in sun, the other in shadow...

Laboratory and environmental decay of wood–plastic composite boards: flexural properties

Treesearch

Rebecca Ibach; Marek Gnatowski; Grace Sun; Jessie Glaeser; Mathew Leung; John Haight

2017-01-01

The flexural properties of wood–plastic composite (WPC) deck boards exposed to 9.5 years of environmental decay in Hilo, Hawaii, were compared to samples exposed to moisture and decay fungi for 12 weeks in the laboratory, to establish a correlation between sample flexural properties and calculated void volume. Specimens were tested for flexural strength and modulus,...

I-5/Gilman advanced technology bridge project

NASA Astrophysics Data System (ADS)

Lanza di Scalea, Francesco; Karbhari, Vistasp M.; Seible, Frieder

2000-04-01

The UCSD led I-5/Gilman Advanced Technology Bridge Project will design and construct a fully functional traffic bridge of advanced composite materials across Interstate 5 in La Jolla, California. Its objective is to demonstrate the use of advanced composite technologies developed by the aerospace industry in commercial applications to increase the life expectancy of new structures and for the rehabilitation of aging infrastructure components. The structure will be a 450 ft long, 60 ft wide cable-stayed bridge supported by a 150 ft A-frame pylon with two vehicular lanes, two bicycle lanes, pedestrian walkways and utility tunnels. The longitudinal girders and pylon will be carbon fiber shells filled with concrete. The transverse deck system will consist of hollow glass/carbon hybrid tubes and a polypropylene fiber reinforced concrete deck with an arch action. Selected cables will be composite. The bridge's structural behavior will be monitored to determine how advanced composite materials perform in civil infrastructure applications. The bridge will be instrumented to obtain performance and structural health data in real time and, where possible, in a remote fashion. The sensors applied to the bridge will include electrical resistance strain gages, fiberoptic Bragg gratings and accelerometers.

Transport systems research vehicle color display system operations manual

NASA Technical Reports Server (NTRS)

Easley, Wesley C.; Johnson, Larry E.

1989-01-01

A recent upgrade of the Transport Systems Research Vehicle operated by the Advanced Transport Operating Systems Program Office at the NASA Langley Research Center has resulted in an all-glass panel in the research flight deck. Eight ARINC-D size CRT color displays make up the panel. A major goal of the display upgrade effort was ease of operation and maintenance of the hardware while maintaining versatility needed for flight research. Software is the key to this required versatility and will be the area demanding the most detailed technical design expertise. This document is is intended to serve as a single source of quick reference information needed for routine operation and system level maintenance. Detailed maintenance and modification of the display system will require specific design documentation and must be accomplished by individuals with specialized knowledge and experience.

Cloud Condensation Nuclei Measurements During the First Year of the ORACLES Study

NASA Astrophysics Data System (ADS)

Kacarab, M.; Howell, S. G.; Wood, R.; Redemann, J.; Nenes, A.

2016-12-01

Aerosols have significant impacts on air quality and climate. Their ability to scatter and absorb radiation and to act as cloud condensation nuclei (CCN) plays a very important role in the global climate. Biomass burning organic aerosol (BBOA) can drastically elevate the concentration of CCN in clouds, but the response in droplet number may be strongly suppressed (or even reversed) owing to low supersaturations that may develop from the strong competition of water vapor (Bougiatioti et al. 2016). Understanding and constraining the magnitude of droplet response to biomass burning plumes is an important component of the aerosol-cloud interaction problem. The southeastern Atlantic (SEA) cloud deck provides a unique opportunity to study these cloud-BBOA interactions for marine stratocumulus, as it is overlain by a large, optically thick biomass burning aerosol plume from Southern Africa during the burning season. The interaction between these biomass burning aerosols and the SEA cloud deck is being investigated in the NASA ObseRvations of Aerosols above Clouds and their intEractionS (ORACLES) study. The CCN activity of aerosol around the SEA cloud deck and associated biomass burning plume was evaluated during the first year of the ORACLES study with direct measurements of CCN concentration, aerosol size distribution and composition onboard the NASA P-3 aircraft during August and September of 2016. Here we present analysis of the observed CCN activity of the BBOA aerosol in and around the SEA cloud deck and its relationship to aerosol size, chemical composition, and plume mixing and aging. We also evaluate the predicted and observed droplet number sensitivity to the aerosol fluctuations and quantify, using the data, the drivers of droplet number variability (vertical velocity or aerosol properties) as a function of biomass burning plume characteristics.

Optimization of aircraft interior panels

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A.; Roper, Willard D.

1986-01-01

Eight different graphite composite panels were fabricated using four different resin matrices. The resin matrices included Hercules 71775, a blend of vinylpolystyrpyridine and bismaleimide, H795, a bismaleimide, Cycom 6162, a phenolic, and PSP 6022M, a polystyrylpyridine. Graphite panels were fabricated using fabric or unidirectional tape. This report describes the processes for preparing these panels and some of their mechanical, thermal and flammability properties. Panel properties are compared with state-of-the-art epoxy fiberglass composite panels.

Compressive and shear buckling analysis of metal matrix composite sandwich panels under different thermal environments

NASA Technical Reports Server (NTRS)

Ko, William L.; Jackson, Raymond H.

1993-01-01

Combined inplane compressive and shear buckling analysis was conducted on flat rectangular sandwich panels using the Raleigh-Ritz minimum energy method with a consideration of transverse shear effect of the sandwich core. The sandwich panels were fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that slightly slender (along unidirectional compressive loading axis) rectangular sandwich panels have the most desirable stiffness-to-weight ratios for aerospace structural applications; the degradation of buckling strength of sandwich panels with rising temperature is faster in shear than in compression; and the fiber orientation of the face sheets for optimum combined-load buckling strength of sandwich panels is a strong function of both loading condition and panel aspect ratio. Under the same specific weight and panel aspect ratio, a sandwich panel with metal matrix composite face sheets has much higher buckling strength than one having monolithic face sheets.

Passive Impact Damage Detection of Fiber Glass Composite Panels

DTIC Science & Technology

2013-12-19

PASSIVE IMPACT DAMAGE DETECTION OF FIBER GLASS COMPOSITE PANELS. By BRUNO ZAMORANO-SENDEROS A dissertation...COVERED 04-11-2012 to 10-12-2013 4. TITLE AND SUBTITLE PASSIVE IMPACT DAMAGE DETECTION OF FIBER GLASS COMPOSITE PANELS 5a. CONTRACT NUMBER 5b...process. .................................... 31 Figure 3-8 Sensor attached to the fiber glass fabric

Effects of Carbon Nanomaterial Reinforcement on Composite Joints Under Cyclic and Impact Loading

DTIC Science & Technology

2012-03-01

prepreg . 2 Figure 1. Composite decks on DDG1000. (From [3]) Figure 2. USV built from nanotube-reinforced carbon fiber composites. (From [2...been proven that the infusion of CNTs enhances the strength and fracture toughness of CFRP laminates under static loading (mode I and mode II...Kostopoulos et al. [5] investigated the influence of the multi-walled carbon nanotubes (MWCNTs) on the impact and after-impact behavior of CFRP laminates

Heat exchanger panel

NASA Technical Reports Server (NTRS)

Warburton, Robert E. (Inventor); Cuva, William J. (Inventor)

2005-01-01

The present invention relates to a heat exchanger panel which has broad utility in high temperature environments. The heat exchanger panel has a first panel, a second panel, and at least one fluid containment device positioned intermediate the first and second panels. At least one of the first panel and the second panel have at least one feature on an interior surface to accommodate the at least one fluid containment device. In a preferred embodiment, each of the first and second panels is formed from a high conductivity, high temperature composite material. Also, in a preferred embodiment, the first and second panels are joined together by one or more composite fasteners.

Investigation of Collapse Characteristics of Cylindrical Composite Panels with Large Cutouts

DTIC Science & Technology

1989-12-01

COLLAPSE CHARACTERISTICS OF CYLINDRICAL COMPOSITE PANELS WITH LARGE CUTOUTS THESIS Scott A. Schimmels Captain, USAF AFIT/GAE/ENY/89D-33 Approved for...public release, distribution unlimited AFIT/GAE/ENY/89D-33 INVESTIGATION OF COLLAPSE * CHARACTERISTICS OF CYLINDRICAL COMPOSITE PANELS WITH LARGE...you would not be reading this. * This thesis research is part of an overall effort in composite nonlinear shell analysis sponsored by AFOSR, Dr

Sustainability of transportation structures using composite materials to support trade and growth.

DOT National Transportation Integrated Search

2014-06-01

Corrosion-induced deterioration of steel rebar is one of the main reasons for repair and rehabilitation programs : for conventional steel-reinforced concrete bridge decks. According to the National Association of Corrosion Engineers : (NACE), of all ...

Live Load Response of Short Span Bridges with Parallam(R) Decks

DOT National Transportation Integrated Search

2007-01-01

Structural Composite Lumber (SCL) is reconstituted with high grade presorted veneers to enhance properties including higher and more uniform strength and stiffness than conventional lumber. Parallel Strand Lumber (PSL) is mainly constituted of wood s...

Payload crew interface design criteria and techniques. Task 1: Inflight operations and training for payloads. [space shuttles

NASA Technical Reports Server (NTRS)

Carmean, W. D.; Hitz, F. R.

1976-01-01

Guidelines are developed for use in control and display panel design for payload operations performed on the aft flight deck of the orbiter. Preliminary payload procedures are defined. Crew operational concepts are developed. Payloads selected for operational simulations were the shuttle UV optical telescope (SUOT), the deep sky UV survey telescope (DUST), and the shuttle UV stellar spectrograph (SUSS). The advanced technology laboratory payload consisting of 11 experiments was selected for a detailed evaluation because of the availability of operational data and its operational complexity.

Quasi-Static Compression and Low-Velocity Impact Behavior of Tri-Axial Bio-Composite Structural Panels Using a Spherical Head

PubMed Central

Li, Jinghao; Hunt, John F; Gong, Shaoqin; Cai, Zhiyong

2017-01-01

This paper presents experimental results of both quasi-static compression and low-velocity impact behavior for tri-axial bio-composite structural panels using a spherical load head. Panels were made having different core and face configurations. The results showed that panels made having either carbon fiber fabric composite faces or a foam-filled core had significantly improved impact and compressive performance over panels without either. Different localized impact responses were observed based on the location of the compression or impact relative to the tri-axial structural core; the core with a smaller structural element had better impact performance. Furthermore, during the early contact phase for both quasi-static compression and low-velocity impact tests, the panels with the same configuration had similar load-displacement responses. The experimental results show basic compression data could be used for the future design and optimization of tri-axial bio-composite structural panels for potential impact applications. PMID:28772542

Laboratory and exterior decay of wood plastic composite boards: voids analysis and computed tomography

Treesearch

Grace Sun; Rebecca E. Ibach; Meghan Faillace; Marek Gnatowski; Jessie A. Glaeser; John Haight

2016-01-01

After exposure in the field and laboratory soil block culture testing, the void content of wood–plastic composite (WPC) decking boards was compared to unexposed samples. A void volume analysis was conducted based on calculations of sample density and from micro-computed tomography (microCT) data. It was found that reference WPC contains voids of different sizes from...

Recent activities in flame retardancy of wood-plastic composites at the Forest Products Laboratory

Treesearch

Robert H. White; Nicole M. Stark; Nadir Ayrilmis

2011-01-01

For a variety of reasons, wood-plastic composite (WPC) products are widely available for some building applications. In applications such as outdoor decking, WPCs have gained a significant share of the market. As an option to improve the efficient use of wood fiber, the USDA Forest Service, Forest Products Laboratory (FPL), has an extensive research program on WPCs....

Development of Guidelines for In-Situ Repair of SLS-Class Composite Flight Hardware

NASA Technical Reports Server (NTRS)

Weber, Thomas P., Jr.; Cox, Sarah B.

2018-01-01

The purpose of composite repair development at KSC (John F. Kennedy Space Center) is to provide support to the CTE (Composite Technology for Exploration) project. This is a multi-space center effort with the goal of developing bonded joint technology for SLS (Space Launch System) -scale composite hardware. At KSC, effective and efficient repair processes need to be developed to allow for any potential damage to composite components during transport or launch preparation. The focus of the composite repair development internship during the spring of 2018 was on the documentation of repair processes and requirements for process controls based on techniques developed through hands-on work with composite test panels. Three composite test panels were fabricated for the purpose of repair and surface preparation testing. The first panel included a bonded doubler and was fabricated to be damaged and repaired. The second and third panels were both fabricated to be cut into lap-shear samples to test the strength of bond of different surface preparation techniques. Additionally, jointed composite test panels were impacted at MSFC (Marshall Space Flight Center) and analyzed for damage patterns. The observations after the impact tests guided the repair procedure at KSC to focus on three repair methods. With a finalized repair plan in place, future work will include the strength testing of different surface preparation techniques, demonstration of repair methods, and repair of jointed composite test panels being impacted at MSFC.

Experimental Study of the Bending Properties and Deformation Analysis of Web-Reinforced Composite Sandwich Floor Slabs with Four Simply Supported Edges.

PubMed

Qi, Yujun; Fang, Hai; Liu, Weiqing

2016-01-01

Web-reinforced composite sandwich panels exhibit good mechanical properties in one-way bending, but few studies have investigated their flexural behavior and deformation calculation methods under conditions of four simply supported edges. This paper studies the bending performance of and deformation calculation methods for two-way web-reinforced composite sandwich panels with different web spacing and heights. Polyurethane foam, two-way orthogonal glass-fiber woven cloth and unsaturated resin were used as raw materials in this study. Vacuum infusion molding was used to prepare an ordinary composite sandwich panel and 5 web-reinforced composite sandwich panels with different spacing and web heights. The panels were subjected to two-way panel bending tests with simple support for all four edges. The mechanical properties of these sandwich panels during the elastic stage were determined by applying uniformly distributed loads. The non-linear mechanical characteristics and failure modes were obtained under centrally concentrated loading. Finally, simulations of the sandwich panels, which used the mechanical model established herein, were used to deduce the formulae for the deflection deformation for this type of sandwich panel. The experimental results show that webs can significantly improve the limit bearing capacity and flexural rigidity of sandwich panels, with smaller web spacing producing a stronger effect. When the web spacing is 75 mm, the limit bearing capacity is 4.63 times that of an ordinary sandwich panel. The deduced deflection calculation formulae provide values that agree well with the measurements (maximum error <15%). The results that are obtained herein can provide a foundation for the structural design of this type of panel.

Experimental Study of the Bending Properties and Deformation Analysis of Web-Reinforced Composite Sandwich Floor Slabs with Four Simply Supported Edges

PubMed Central

Qi, Yujun; Fang, Hai; Liu, Weiqing

2016-01-01

Web-reinforced composite sandwich panels exhibit good mechanical properties in one-way bending, but few studies have investigated their flexural behavior and deformation calculation methods under conditions of four simply supported edges. This paper studies the bending performance of and deformation calculation methods for two-way web-reinforced composite sandwich panels with different web spacing and heights. Polyurethane foam, two-way orthogonal glass-fiber woven cloth and unsaturated resin were used as raw materials in this study. Vacuum infusion molding was used to prepare an ordinary composite sandwich panel and 5 web-reinforced composite sandwich panels with different spacing and web heights. The panels were subjected to two-way panel bending tests with simple support for all four edges. The mechanical properties of these sandwich panels during the elastic stage were determined by applying uniformly distributed loads. The non-linear mechanical characteristics and failure modes were obtained under centrally concentrated loading. Finally, simulations of the sandwich panels, which used the mechanical model established herein, were used to deduce the formulae for the deflection deformation for this type of sandwich panel. The experimental results show that webs can significantly improve the limit bearing capacity and flexural rigidity of sandwich panels, with smaller web spacing producing a stronger effect. When the web spacing is 75 mm, the limit bearing capacity is 4.63 times that of an ordinary sandwich panel. The deduced deflection calculation formulae provide values that agree well with the measurements (maximum error <15%). The results that are obtained herein can provide a foundation for the structural design of this type of panel. PMID:26871435

Bridge deck cracking and composite action analyses : final report, March 2010.

DOT National Transportation Integrated Search

2010-03-01

According to the American Society of Civil Engineers Report Card (ASCE, 2005), United States infrastructure received a grade point average of "D"(i.e., poor rating) in 2005. Moreover, the National Bridge Inventory (Federal Highway Administration, 200...

Vibroacoustic Model Validation for a Curved Honeycomb Composite Panel

NASA Technical Reports Server (NTRS)

Buehrle, Ralph D.; Robinson, Jay H.; Grosveld, Ferdinand W.

2001-01-01

Finite element and boundary element models are developed to investigate the vibroacoustic response of a curved honeycomb composite sidewall panel. Results from vibroacoustic tests conducted in the NASA Langley Structural Acoustic Loads and Transmission facility are used to validate the numerical predictions. The sidewall panel is constructed from a flexible honeycomb core sandwiched between carbon fiber reinforced composite laminate face sheets. This type of construction is being used in the development of an all-composite aircraft fuselage. In contrast to conventional rib-stiffened aircraft fuselage structures, the composite panel has nominally uniform thickness resulting in a uniform distribution of mass and stiffness. Due to differences in the mass and stiffness distribution, the noise transmission mechanisms for the composite panel are expected to be substantially different from those of a conventional rib-stiffened structure. The development of accurate vibroacoustic models will aide in the understanding of the dominant noise transmission mechanisms and enable optimization studies to be performed that will determine the most beneficial noise control treatments. Finite element and boundary element models of the sidewall panel are described. Vibroacoustic response predictions are presented for forced vibration input and the results are compared with experimental data.

Field-incidence transmission of treated orthotropic and laminated composite panels

NASA Technical Reports Server (NTRS)

Koval, L. R.

1983-01-01

In an effort to improve understanding of the phenomenon of noise transmission through the sidewalls of an aircraft fuselage, an analytical model was developed for the field incidence transmission loss of an orthotropic or laminated composite infinite panel with layers of various noise insulation treatments. The model allows for four types of treatments, impervious limp septa, orthotropic trim panels, porous blankets, and air spaces, while it also takes into account the effects of forward speed. Agreement between the model and transmission loss data for treated panels is seen to be fairly good overall. In comparison with transmission loss data for untreated composite panels, excellent agreement occurred.

Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

Treesearch

Nicole M. Stark; Zhiyong Cai; Charles Carll

2010-01-01

This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

Composite panel development at JPL

NASA Technical Reports Server (NTRS)

Mcelroy, Paul; Helms, Rich

1988-01-01

Parametric computer studies can be use in a cost effective manner to determine optimized composite mirror panel designs. An InterDisciplinary computer Model (IDM) was created to aid in the development of high precision reflector panels for LDR. The materials properties, thermal responses, structural geometries, and radio/optical precision are synergistically analyzed for specific panel designs. Promising panels designs are fabricated and tested so that comparison with panel test results can be used to verify performance prediction models and accommodate design refinement. The iterative approach of computer design and model refinement with performance testing and materials optimization has shown good results for LDR panels.

Manning's roughness coefficient for buried composite arch bridges.

DOT National Transportation Integrated Search

2014-08-01

This report includes fulfillment of Task 9 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 9 investigates the interaction of water flow under the bridge with the tubes and : decking and recom...

VSTOL Systems Research Aircraft (VSRA) Harrier

NASA Technical Reports Server (NTRS)

1994-01-01

NASA's Ames Research Center has developed and is testing a new integrated flight and propulsion control system that will help pilots land aircraft in adverse weather conditions and in small confined ares (such as, on a small ship or flight deck). The system is being tested in the V/STOL (Vertical/Short Takeoff and Landing) Systems research Aircraft (VSRA), which is a modified version of the U.S. Marine Corps's AV-8B Harrier jet fighter, which can take off and land vertically. The new automated flight control system features both head-up and panel-mounted computer displays and also automatically integrates control of the aircraft's thrust and thrust vector control, thereby reducing the pilot's workload and help stabilize the aircraft for landing. Visiting pilots will be encouraged to test the new system and provide formal evaluation flights data and feedback. An actual flight test and the display panel of control system are shown in this video.

Improving the color stability of wood-plastic composites through fiber pre-treatment

Treesearch

Nicole M. Stark; Scott A. Mueller

2008-01-01

Wood-plastic composites (WPCs) continue to make inroads into the decking market. One of the main drawbacks from the consumer’s perspective is that they can fade during weathering. It has been shown that WPCs fade more when exposed to a combination of light and water spray than when exposed only to light. This suggests that the loss of the color-imparting extractives...

Mechanical and time-dependent behavior of wood-plastic composites subjected to bending

Treesearch

S. E. Hamel; John Hermanson; S. M. Cramer

2015-01-01

The most popular use of wood–plastic composite (WPC) members in the United States has been as outdoor decking material in residential construction. If the use of these products expands into more structural applications, such as beams and joists, it is imperative that the material’s mechanical behavior be understood. Since most of the potential structural uses of this...

Damage Tolerance of Pre-Stressed Composite Panels Under Impact Loads

NASA Astrophysics Data System (ADS)

Johnson, Alastair F.; Toso-Pentecôte, Nathalie; Schueler, Dominik

2014-02-01

An experimental test campaign studied the structural integrity of carbon fibre/epoxy panels preloaded in tension or compression then subjected to gas gun impact tests causing significant damage. The test programme used representative composite aircraft fuselage panels composed of aerospace carbon fibre toughened epoxy prepreg laminates. Preload levels in tension were representative of design limit loads for fuselage panels of this size, and maximum compression preloads were in the post-buckle region. Two main impact scenarios were considered: notch damage from a 12 mm steel cube projectile, at velocities in the range 93-136 m/s; blunt impact damage from 25 mm diameter glass balls, at velocities 64-86 m/s. The combined influence of preload and impact damage on panel residual strengths was measured and results analysed in the context of damage tolerance requirements for composite aircraft panels. The tests showed structural integrity well above design limit loads for composite panels preloaded in tension and compression with visible notch impact damage from hard body impact tests. However, blunt impact tests on buckled compression loaded panels caused large delamination damage regions which lowered plate bending stiffness and reduced significantly compression strengths in buckling.

Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Upper Deck, Second Deck and Hold - Saugatuck, James River Reserve Fleet, Newport News, Newport News, VA

A novel strategy to increase separated electron-hole dipoles in commercial Si based solar panel to assist photovoltaic effect

NASA Astrophysics Data System (ADS)

Feng, Yefeng; He, Cheng-En; Xu, Zhichao; Hu, Jianbing; Peng, Cheng

2018-01-01

Interface induced polarization has been found to have a significant impact on dielectric properties of 2-2 type polymer composites bearing Si based semi-conducting ceramic sheets. Inherent overall polarity of polymer layers in 2-2 composites has been verified to be closely connected with interface effect and achieved permittivity in composites. In present work, conducting performances of monocrystalline Si sheets coated by varied high polarity material layers were deeply researched. The positive results inspired us to propose a novel strategy to improve separated electron-hole dipoles in commercial Si based solar cell panel for assisting photovoltaic effect, based on strong interface induced polarization. Conducting features of solar panels coated by two different high polarity polymer layers were detected to be greatly elevated compared with solar panel standalone, thanks to interface induced polarization between panel and polymer. Polymer coating with higher polarity would lead to more separated electron-hole dipole pairs in solar panel contributing to higher conductivity of panel. Valid synergy of interface effect and photovoltaic effect was based on their unidirectional traits of electron transfer. Dielectric properties of solar panels in composites further confirmed that strategy. This work might provide a facile route to prepare promising Si based solar panels with higher photoelectric conversion efficiency by enhancing interface induced polarization between panel and polymer coating.

Design of Fiber Reinforced Foam Sandwich Panels for Large Ares V Structural Applications

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Arnold, Steven M.; Hopkins, Dale A.

2010-01-01

The preliminary design of three major structural components within NASA's Ares V heavy lift vehicle using a novel fiber reinforced foam composite sandwich panel concept is presented. The Ares V payload shroud, interstage, and core intertank are designed for minimum mass using this panel concept, which consists of integral composite webs separated by structural foam between two composite facesheets. The HyperSizer structural sizing software, in conjunction with NASTRAN finite element analyses, is used. However, since HyperSizer does not currently include a panel concept for fiber reinforced foam, the sizing was performed using two separate approaches. In the first, the panel core is treated as an effective (homogenized) material, whose properties are provided by the vendor. In the second approach, the panel is treated as a blade stiffened sandwich panel, with the mass of the foam added after completion of the panel sizing. Details of the sizing for each of the three Ares V components are given, and it is demonstrated that the two panel sizing approaches are in reasonable agreement for thinner panel designs, but as the panel thickness increases, the blade stiffened sandwich panel approach yields heavier panel designs. This is due to the effects of local buckling, which are not considered in the effective core property approach.

Tensile strength of composite sheets with unidirectional stringers and crack-like damage: A brief report

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1984-01-01

The residual strength of composite sheets with bonded composite stringers loaded in tension was determined. The results are summarized. About 50 graphite/epoxy composite panels with crack-like slots were monotonically loaded in tension to failure. Both sheet layup and stringer configuration were varied. The composite panels have considerable damage tolerance. The stringers arrested cracks that ran from the crack-like slots, and the residual strengths were considerably greater than those of unstiffened composite sheets. A stress-intensity factor analysis was developed to predict the failing strains of the stiffened panels. Using the analysis, a single design curve was produced for composite sheets with bonded stringers of any configuration.

Analytical and experimental study of structurally efficient composite hat-stiffened panels loaded in axial compression

NASA Technical Reports Server (NTRS)

Williams, J. G.; Mikulus, M. M., Jr.

1976-01-01

Structural efficiency studies were made to determine the weight saving potential of graphite/epoxy composite structures for compression panel applications. Minimum weight hat-stiffened and open corrugation configurations were synthesized using a nonlinear mathematical programming technique. Selected configurations were built and tested to study local and Euler buckling characteristics. Test results for 23 panels critical in local buckling and six panels critical in Euler buckling are compared with analytical results obtained using the BUCLASP-2 branched plate buckling program. A weight efficiency comparison is made between composite and aluminum compression panels using metal test data generated by the NACA. Theoretical studies indicate that potential weight savings of up to 50% are possible for composite hat-stiffened panels when compared with similar aluminum designs. Weight savings of 32% to 42% were experimentally achieved. Experience suggests that most of the theoretical weight saving potential is available if design deficiencies are eliminated and strict fabrication control is exercised.

Study of noise reduction characteristics of composite fiber-reinforced panels, interior panel configurations, and the application of the tuned damper concept

NASA Technical Reports Server (NTRS)

Lameris, J.; Stevenson, S.; Streeter, B.

1982-01-01

The application of fiber reinforced composite materials, such as graphite epoxy and Kevlar, for secondary or primary structures developing in the commercial airplane industry was investigated. A composite panel program was initiated to study the effects of some of the parameters that affect noise reduction of these panels. The fiber materials and the ply orientation were chosen to be variables in the test program. It was found that increasing the damping characteristics of a structural panel will reduce the vibration amplitudes at resonant frequencies with attendant reductions in sound reduction. Test results for a dynamic absorber, a tuned damper, are presented and evaluated.

JTEC panel report on advanced composites in Japan

NASA Technical Reports Server (NTRS)

Diefendorf, R. J.; Grisaffe, S. J.; Hillig, W. B.; Perepezko, J. H.; Pipes, R. B.; Sheehan, J. E.

1991-01-01

The JTEC Panel on Advanced Composites visited Japan and surveyed the status and future directions of Japanese high performance ceramic and carbon fibers and their composites in metal, intermetallic, ceramic and carbon matrices. The panel's interests included not only what composite systems were chosen, but also how these systems were developed. A strong carbon and fiber industry makes Japan the leader in carbon fiber technology. Japan has initiated an oxidation resistant carbon/carbon composite program. The goals for this program are ambitious, and it is just starting, but its progress should be closely monitored in the United States.

Fatigue behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP)

Treesearch

Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

2015-01-01

The static and fatigue bending behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP) has been investigated by four-point bending tests. Fatigue panels and weakened panels (wESCP) with an initial interface defect were manufactured for the fatigue tests. Stress σ vs. number of cycles curves (S-N) were recorded under the different stress...

Finite element simulation of a novel composite light-weight microporous cladding panel

NASA Astrophysics Data System (ADS)

Tian, Lida; Wang, Dongyan

2018-04-01

A novel composite light-weight microporous cladding panel with matched connection detailing is developed. Numerical simulation on the experiment is conducted by ABAQUS. The accuracy and rationality of the finite element model is verified by comparison between the simulation and the experiment results. It is also indicated that the novel composite cladding panel is of desirable bearing capacity, stiffness and deformability under out-of-plane load.

Design recommendations for the optimized continuity diaphragm for prestressed concrete bulb-T beams.

DOT National Transportation Integrated Search

2008-01-01

This research focused on prestressed concrete bulb-T (PCBT) beams made composite with a cast-in-place concrete deck and continuous over several spans through the use of continuity diaphragms. The current design procedure in AASHTO states that a conti...

NIMS Observes the Structure and Composition of Jupiter Clouds

NASA Image and Video Library

1998-03-26

With the NIMS instrument high quality observations are being obtained from all parts of Jupiter. The images in the upper panel are taken at a wavelength of 4.8 microns. At this wavelength thermal radiation from about 100 km deep below the visible cloud deck is escaping, allowing us to study the deep atmospheric region. The overlying cloud deck absorbs a part of the radiation, but there are places where it is thin and more radiation can escape. These are called hot spot regions. Many hotspots regions occur in a zone between the equator and 15 degrees north latitude, the North Equatorial Belt (NEB), but thermal radiation is seen from much of the planet. The uniqueness of NIMS is that it is capable of observing the same spatial region at a maximum of 408 different wavelengths between 0.7 and 5.2 micron simultaneously. Every picture element (pixel) contains a spectrum of up to 408 wavelengths. The gases that compose the atmosphere leave there traces in the spectra. In this particular case, 48 wavelengths were available between 4.6 and 5.2 micron, and we see spectral signatures of water, ammonia, and phosphine. Also, the total amount of radiation is determined by the amount of overlying cloud, characterized by the cloud opacity. By means of model calculations, we can determine the amount of water and the cloud opacity for each individual spectrum. The amount ammonia and phosphine is more difficult to obtain because its influence on the spectra is weaker. The results of these calculations are shown in the form of maps in the next two panels. With NIMS, we can now have a detailed look at the spatial distribution of the water and ammonia amounts and the cloud opacity in the atmosphere. Not all the pixels from the observations have good spectra, so for some data points no reliable determination of the water and cloud opacity could be made. We find that the atmosphere is extremely dry in, and close to, the hot spot, with relative humidities between 0.02 % and 10 %, with the dryest places being inside the hot spot. This corroborates the in-situ Galileo Entry Probe measurements. The Probe entered the atmosphere, on December 5 1995, in a hot spot region. Whereas the Probe obtained only a very localized snapshot, with NIMS we can do observations of larger areas and over longer periods. The spatial distribution of water is more complex than expected. More detailed investigations will be necessary to fully understand these results. http://photojournal.jpl.nasa.gov/catalog/PIA01224

Injection repair of carbon fiber/bismaleimide composite panels with bisphenol E cyanate ester resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thunga, Mahendra; Bauer, Amy; Obusek, Kristine

2014-08-01

Resin injection of bisphenol E cyanate ester, a low viscosity resin that cures into a high temperature thermoset polymer, is investigated as a reliable repair method to restore strength and stiffness in delaminated carbon fiber/bismaleimide composites used in aircraft panels. The influence of temperature on the viscosity of the uncured resin was measured to optimize the injection conditions for high resin infiltration into the delaminations. The repair efficiency of the resin was evaluated by varying the panel thickness and the method by which the delamination damage was created in the composite specimens. Ultrasonic scanning (C-scan), flash thermography images, and cross-sectionmore » analysis of repaired panels revealed excellent resin infiltration into the damaged region. Evaluation of mechanical repair efficiency using both bending stiffness and in-plain compressive strength of the composite panels as the repair metrics showed values exceeding 100%.« less

OV-104's RMS releases Gamma Ray Observatory (GRO) during STS-37 deployment

NASA Image and Video Library

1991-04-07

Atlantis', Orbiter Vehicle (OV) 104's, remote manipulator system (RMS) releases Gamma Ray Observatory (GRO) during STS-37 deployment. Visible on the GRO as it drifts away from the RMS end effector are the four complement instruments: the Energetic Gamma Ray Experiment (bottom); Imaging Compton Telescope (COMPTEL) (center); Oriented Scintillation Spectrometer Experiment (OSSE) (top); and Burst and Transient Source Experiment (BATSE) (at four corners). GRO's solar array (SA) panels are extended and are in orbit configuration. View was taken through aft flight deck window which reflects some of the crew compartment interior.

Effect of low-velocity or ballistic impact damage on the strength of thin composite and aluminum shear panels

NASA Technical Reports Server (NTRS)

Farley, G. L.

1985-01-01

Impact tests were conducted on shear panels fabricated from 6061-T6 aluminum and from woven fabric prepreg of Du Pont Kevlara fiber/epoxy resin and graphite fiber/epoxy resin. The shear panels consisted of three different composite laminates and one aluminum material configuration. Three panel aspect ratios were evaluated for each material configuration. Composite panels were impacted with a 1.27-cm (0.05-in) diameter aluminum sphere at low velocities of 46 m/sec (150 ft/sec) and 67 m/sec (220 ft/sec). Ballistic impact conditions consisted of a tumbled 0.50-caliber projectile impacting loaded composite and aluminum shear panels. The results of these tests indicate that ballistic threshold load (the lowest load which will result in immediate failure upon penetration by the projectile) varied between 0.44 and 0.61 of the average failure load of undamaged panels. The residual strengths of the panels after ballistic impact varied between 0.55 and 0.75 of the average failure strength of the undamaged panels. The low velocity impacts at 67 m/sec (220 ft/sec) caused a 15 to 20 percent reduction in strength, whereas the impacts at 46 m/sec (150 ft/sec) resulted in negligible strength loss. Good agreement was obtained between the experimental failure strengths and the predicted strength with the point stress failure criterion.

Composite Sandwich Structures for Shock Mitigation and Energy Absorption

DTIC Science & Technology

2016-06-28

analysis of the blast performance of foam -core, composite sandwich panels was that on a per unit areal weight density basis, lighter and more crushable... foam cores offered greater blast resistance and energy absorption than the heavier and stronger foam cores. This was found to be the case even on an...absolute weight basis for cuNed sandwich panels and panels subjected to underwater blast. 15. SUBJECT TERMS composite; foam -core sandwich; blast

Experimental Study on Composite Light-weight Microporous Concrete Cladding Panels

NASA Astrophysics Data System (ADS)

Lida, Tian; Dongyan, Wang; Kang, Liu

2018-03-01

A new type of composite light-weight microporous concrete cladding panel was developed, with the compound function of retaining and heat preservation. Two specimens of the new cladding panel and connection detailing were made for out-of-plane bending experiment. The results indicate that the new cladding panel and its connection detailing are of sufficient stiffness, bearing capacity and deformability under wind load and out-of-plane seismic action.

Finite Element Analysis of the Random Response Suppression of Composite Panels at Elevated Temperatures using Shape Memory Alloy Fibers

NASA Technical Reports Server (NTRS)

Turner, Travis L.; Zhong, Z. W.; Mei, Chuh

1994-01-01

A feasibility study on the use of shape memory alloys (SMA) for suppression of the random response of composite panels due to acoustic loads at elevated temperatures is presented. The constitutive relations for a composite lamina with embedded SMA fibers are developed. The finite element governing equations and the solution procedures for a composite plate subjected to combined acoustic and thermal loads are presented. Solutions include: 1) Critical buckling temperature; 2) Flat panel random response; 3) Thermal postbuckling deflection; 4) Random response of a thermally buckled panel. The preliminary results demonstrate that the SMA fibers can completely eliminate the thermal postbuckling deflection and significantly reduce the random response at elevated temperatures.

Characterizing the Response of Composite Panels to a Pyroshock Induced Environment Using Design of Experiments Methodology

NASA Technical Reports Server (NTRS)

Parsons, David S.; Ordway, David; Johnson, Kenneth

2013-01-01

This experimental study seeks to quantify the impact various composite parameters have on the structural response of a composite structure in a pyroshock environment. The prediction of an aerospace structure's response to pyroshock induced loading is largely dependent on empirical databases created from collections of development and flight test data. While there is significant structural response data due to pyroshock induced loading for metallic structures, there is much less data available for composite structures. One challenge of developing a composite pyroshock response database as well as empirical prediction methods for composite structures is the large number of parameters associated with composite materials. This experimental study uses data from a test series planned using design of experiments (DOE) methods. Statistical analysis methods are then used to identify which composite material parameters most greatly influence a flat composite panel's structural response to pyroshock induced loading. The parameters considered are panel thickness, type of ply, ply orientation, and pyroshock level induced into the panel. The results of this test will aid in future large scale testing by eliminating insignificant parameters as well as aid in the development of empirical scaling methods for composite structures' response to pyroshock induced loading.

Characterizing the Response of Composite Panels to a Pyroshock Induced Environment using Design of Experiments Methodology

NASA Technical Reports Server (NTRS)

Parsons, David S.; Ordway, David O.; Johnson, Kenneth L.

2013-01-01

This experimental study seeks to quantify the impact various composite parameters have on the structural response of a composite structure in a pyroshock environment. The prediction of an aerospace structure's response to pyroshock induced loading is largely dependent on empirical databases created from collections of development and flight test data. While there is significant structural response data due to pyroshock induced loading for metallic structures, there is much less data available for composite structures. One challenge of developing a composite pyroshock response database as well as empirical prediction methods for composite structures is the large number of parameters associated with composite materials. This experimental study uses data from a test series planned using design of experiments (DOE) methods. Statistical analysis methods are then used to identify which composite material parameters most greatly influence a flat composite panel's structural response to pyroshock induced loading. The parameters considered are panel thickness, type of ply, ply orientation, and pyroshock level induced into the panel. The results of this test will aid in future large scale testing by eliminating insignificant parameters as well as aid in the development of empirical scaling methods for composite structures' response to pyroshock induced loading.

Plans: 3'/50 Cal. Gun Platform, Boat Deck House Top & ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Plans: 3'/50 Cal. Gun Platform, Boat Deck House Top & Fidley Top, Boat Deck, Radar Platform Lower, Pilot House Top, Navigation Bridge, Upper Bridge Deck, Poop Deck, Cargo Deck, Motor Boat Platform, Bridge Deck, Forecastle Deck, Upper Deck - Taluga, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

High Speed Thermal Imaging on Ballistic Impact of Triaxially Braided Composites

NASA Technical Reports Server (NTRS)

Johnston, Joel P.; Pereira, J. Michael; Ruggeri, Charles R.; Roberts, Gary D.

2017-01-01

Ballistic impact experiments were performed on triaxially braided polymer matrix composites to study the heat generated in the material due to projectile velocity and penetration damage. Quantifying the heat generation phenomenon is crucial for attaining a better understanding of composite behavior and failure under impact loading. The knowledge gained can also be used to improve physics-based models which can numerically simulate impact of composites. Triaxially braided (0/+60/-60) composite panels were manufactured with T700S standard modulus carbon fiber and two epoxy resins. The PR520 (toughened) and 3502 (untoughened) resin systems were used to make different panels to study the effects of resin properties on temperature rise. Ballistic impact tests were conducted on these composite panels using a gas gun, and different projectile velocities were applied to study the effect on the temperature results. Temperature contours were obtained from the rear surface of the panel during the test through a high speed, infrared (IR) thermal imaging system. The contours show that high temperatures were locally generated and more pronounced along the axial tows for the T700S/PR520 composite specimens; whereas, tests performed on T700S/3502 composite panels using similar impact velocities demonstrated a widespread area of lower temperature rises. Nondestructive, ultrasonic C-scan analyses were performed to observe and verify the failure patterns in the impacted panels. Overall, the impact experimentation showed temperatures exceeding 525 K (485degF) in both composites which is well above the respective glass transition temperatures for the polymer constituents. This expresses the need for further high strain rate testing and measurement of the temperature and deformation fields to fully understand the complex behavior and failure of the material in order to improve the confidence in designing aerospace components with these materials.

Composite armor, armor system and vehicle including armor system

DOEpatents

Chu, Henry S.; Jones, Warren F.; Lacy, Jeffrey M.; Thinnes, Gary L.

2013-01-01

Composite armor panels are disclosed. Each panel comprises a plurality of functional layers comprising at least an outermost layer, an intermediate layer and a base layer. An armor system incorporating armor panels is also disclosed. Armor panels are mounted on carriages movably secured to adjacent rails of a rail system. Each panel may be moved on its associated rail and into partially overlapping relationship with another panel on an adjacent rail for protection against incoming ordnance from various directions. The rail system may be configured as at least a part of a ring, and be disposed about a hatch on a vehicle. Vehicles including an armor system are also disclosed.

Application of Interface Technology in Progressive Failure Analysis of Composite Panels

NASA Technical Reports Server (NTRS)

Sleight, D. W.; Lotts, C. G.

2002-01-01

A progressive failure analysis capability using interface technology is presented. The capability has been implemented in the COMET-AR finite element analysis code developed at the NASA Langley Research Center and is demonstrated on composite panels. The composite panels are analyzed for damage initiation and propagation from initial loading to final failure using a progressive failure analysis capability that includes both geometric and material nonlinearities. Progressive failure analyses are performed on conventional models and interface technology models of the composite panels. Analytical results and the computational effort of the analyses are compared for the conventional models and interface technology models. The analytical results predicted with the interface technology models are in good correlation with the analytical results using the conventional models, while significantly reducing the computational effort.

Optimal Design of Grid-Stiffened Composite Panels Using Global and Local Buckling Analysis

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Jaunky, Navin; Knight, Norman F., Jr.

1996-01-01

A design strategy for optimal design of composite grid-stiffened panels subjected to global and local buckling constraints is developed using a discrete optimizer. An improved smeared stiffener theory is used for the global buckling analysis. Local buckling of skin segments is assessed using a Rayleigh-Ritz method that accounts for material anisotropy and transverse shear flexibility. The local buckling of stiffener segments is also assessed. Design variables are the axial and transverse stiffener spacing, stiffener height and thickness, skin laminate, and stiffening configuration. The design optimization process is adapted to identify the lightest-weight stiffening configuration and pattern for grid stiffened composite panels given the overall panel dimensions, design in-plane loads, material properties, and boundary conditions of the grid-stiffened panel.

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Rich, M. J.; Lowry, D. W.

1985-01-01

An assessment of composite helicopter structures, exposed to environmental effects, after four years of commercial service is presented. This assessment is supported by test results of helicopter components and test panels which have been exposed to environmental effects since late 1979. Full scale static and fatigue tests are being conducted on composite components obtained from S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale tests are being conducted on coupons obtained from panels being exposed to outdoor conditions in Stratford, Connecticut and West Palm Beach, Florida. The panel layups represent S-76 components. Moisture evaluations and strength tests are being conducted, on the S-76 components and panels, over a period of eight years. Results are discussed for components and panels with up to four years of exposure.

Sound Transmission Through a Curved Honeycomb Composite Panel

NASA Technical Reports Server (NTRS)

Klos, Jacob; Robinson, Jay H.; Buehrle, Ralph D.

2003-01-01

Composite structures are often used in aircraft because of the advantages offered by a high strength to weight ratio. However, the acoustical properties of these light and stiff structures can often be less than desirable resulting in high aircraft interior noise levels. In this paper, measurements and predictions of the transmission loss of a curved honeycomb composite panel are presented. The transmission loss predictions are validated by comparisons to measurements. An assessment of the behavior of the panel is made from the dispersion characteristics of transverse waves propagating in the panel. The speed of transverse waves propagating in the panel is found to be sonic or supersonic over the frequency range from 100 to 5000 Hz. The acoustical benefit of reducing the wave speed for transverse vibration is demonstrated.

Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, Boat Deck, House Top, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Gun Platform, Upper Deck, Second Deck and Hold Plan - Mission Santa Ynez, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

Flight service evaluation of Kevlar-49/epoxy composite panels in wide-bodied commercial transport aircraft

NASA Technical Reports Server (NTRS)

Stone, R. H.

1977-01-01

Kevlar-49 fairing panels, installed as flight service components on three L-1011s, were inspected after three years' service, and found to be performing satisfactorily. There are six Kevlar-49 panels on each aircraft, including sandwich and solid laminate wing-body panels, and 150 C service aft engine fairings. The service history to date indicates that Kevlar-49 epoxy composite materials have satisfactory service characteristics for use in aircraft secondary structure.

Effect of Carbon Nanotubes Upon Emissions From Cutting and Sanding Carbon Fiber-Epoxy Composites

PubMed Central

Heitbrink, William A.; Lo, Li-Ming

2015-01-01

Carbon nanotubes (CNTs) are being incorporated into structural composites to enhance material strength. During fabrication or repair activities, machining nanocomposites may release CNTs into the workplace air. An experimental study was conducted to evaluate the emissions generated by cutting and sanding on three types of epoxy-composite panels: Panel A containing graphite fibers, Panel B containing graphite fibers and carbon-based mat, and Panel C containing graphite fibers, carbon-based mat, and multi-walled CNTs. Aerosol sampling was conducted with direct-reading instruments, and filter samples were collected for measuring elemental carbon (EC) and fiber concentrations. Our study results showed that cutting Panel C with a band saw did not generate detectable emissions of fibers inspected by transmission electron microscopy but did increase the particle mass, number, and EC emission concentrations by 20% to 80% compared to Panels A and B. Sanding operation performed on two Panel C resulted in fiber emission rates of 1.9×108 and 2.8×106 fibers per second (f/s), while no free aerosol fibers were detected from sanding Panels A and B containing no CNTs. These free CNT fibers may be a health concern. However, the analysis of particle and EC concentrations from these same samples cannot clearly indicate the presence of CNTs, because extraneous aerosol generation from machining the composite epoxy material increased the mass concentrations of the EC. PMID:26478716

Evaluating the warping of laminated particleboard panels

Treesearch

Zhiyong Cai

2004-01-01

Laminated wood composites have been used widely in the secondary manufacturing processes in the wood panel industries. Warping, which is defined as the out-of-plane deformation of an initially flat panel, is a longstanding problem associated with the use of laminated wood composites. The mechanism of warping is still not fully understood. A new two- dimensional warping...

Structural composite panel performance under long-term load

Treesearch

Theodore L. Laufenberg

1988-01-01

Information on the performance of wood-based structural composite panels under long-term load is currently needed to permit their use in engineered assemblies and systems. A broad assessment of the time-dependent properties of panels is critical for creating databases and models of the creep-rupture phenomenon that lead to reliability-based design procedures. This...

Influence of reinforcement type on the mechanical behavior and fire response of hybrid composites and sandwich structures

NASA Astrophysics Data System (ADS)

Giancaspro, James William

Lightweight composites and structural sandwich panels are commonly used in marine and aerospace applications. Using carbon, glass, and a host of other high strength fiber types, a broad range of laminate composites and sandwich panels can be developed. Hybrid composites can be constructed by laminating multiple layers of varying fiber types while sandwich panels are manufactured by laminating rigid fiber facings onto a lightweight core. However, the lack of fire resistance of the polymers used for the fabrication remains a very important problem. The research presented in this dissertation deals with an inorganic matrix (Geopolymer) that can be used to manufacture laminate composites and sandwich panels that are resistant up to 1000°C. This dissertation deals with the influence of fiber type on the mechanical behavior and the fire response of hybrid composites and sandwich structures manufactured using this resin. The results are categorized into the following distinct studies. (i) High strength carbon fibers were combined with low cost E-glass fibers to obtain hybrid laminate composites that are both economical and strong. The E-glass fabrics were used as a core while the carbon fibers were placed on the tension face and on both tension and compression faces. (ii) Structural sandwich beams were developed by laminating various types of reinforcement onto the tension and compression faces of balsa wood cores. The flexural behavior of the beams was then analyzed and compared to beams reinforced with organic composite. The effect of core density was evaluated using oak beams reinforced with inorganic composite. (iii) To measure the fire response, balsa wood sandwich panels were manufactured using a thin layer of a fire-resistant paste to serve for fire protection. Seventeen sandwich panels were fabricated and tested to measure the heat release rates and smoke-generating characteristics. The results indicate that Geopolymer can be effectively used to fabricate both high strength composite plates and sandwich panels. A 2 mm thick coating of fireproofing on balsa wood is sufficient to satisfy FAA fire requirements.

Blended-Wing-Body Structural Technology Study

NASA Technical Reports Server (NTRS)

Starnes, James H.

1998-01-01

In most studies of stability of plates, the axial stress has been taken as uniform compression throughout flat rectangular plates. Buckling of isotropic plates under a compressive stress that varies linearly from one loaded edge to the other has been studied by Libove et al. Cases of practical interest exist, however, in which the axial stress is not uniform but varies from tension at both loaded edges to compression in the middle. An example is the stability of the crown of the hat stiffened panel, a candidate configuration of the upper and lower skin of the Blended Wing Body (BWB) Aircraft. The BWB Aircraft is an advanced long-range ultra-high-capacity airliner with the principal feature being the pressurized wide double-deck body which is blended into the wing. In the present research, analytical methods are used to investigate the local stability of the crown in order to minimize its weight while optimizing its buckling strength. The crown is modeled as a rectangular laminated composite plate subjected to a second degree parabolic variation of axial stresses in the longitudinal direction. A varying tension-compression- tension axial stresses are induced in the crown of the stiffeners due to bending. The change in axial stresses is equilibrated by nonuniform shear stresses along the plate edges and transverse normal stresses.

Material development for laminar flow control wing panels

NASA Technical Reports Server (NTRS)

Meade, L. E.

1977-01-01

The absence of suitable porous materials or techniques for the economic perforation of surface materials has previously restricted the design of laminar flow control (LFC) wing panels to a consideration of mechanically slotted LFC surfaces. A description is presented of a program which has been conducted to exploit recent advances in materials and manufacturing technology for the fabrication of reliable porous or perforated LFC surface panels compatible with the requirements of subsonic transport aircraft. Attention is given to LFC design criteria, surface materials, surface concepts, the use of microporous composites, perforated composites, and perforated metal. The described program was successful in that fabrication processes were developed for producing predictable perforated panels both of composite and of metal.

Fiber Reinforced Composite Cores and Panels

NASA Technical Reports Server (NTRS)

Day, Stephen W. (Inventor); Campbell, G. Scott (Inventor); Tilton, Danny E. (Inventor); Stoll, Frederick (Inventor); Sheppard, Michael (Inventor); Banerjee, Robin (Inventor)

2013-01-01

A fiber reinforced core panel is formed from strips of plastics foam helically wound with layers of rovings to form webs which may extend in a wave pattern or may intersect transverse webs. Hollow tubes may replace foam strips. Axial rovings cooperate with overlying helically wound rovings to form a beam or a column. Wound roving patterns may vary along strips for structural efficiency. Wound strips may alternate with spaced strips, and spacers between the strips enhance web buckling strength. Continuously wound rovings between spaced strips permit folding to form panels with reinforced edges. Continuously wound strips are helically wrapped to form annular structures, and composite panels may combine both thermoset and thermoplastic resins. Continuously wound strips or strip sections may be continuously fed either longitudinally or laterally into molding apparatus which may receive skin materials to form reinforced composite panels.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Alexander; Jernigan, Dann A.; Dodd, Amanda B.

New aircraft are being designed with increasing quantities of composite materials used in their construction. Different from the more traditional metals, composites have a higher propensity to burn. This presents a challenge to transportation safety analyses, as the aircraft structure now represents an additional fuel source involved in the fire scenario. Most of the historical fire testing of composite materials is aime d at studying kinetics, flammability or yield strength under fire conditions. Most of this testing is small - scale. Heterogeneous reactions are often length - scale dependent, and this is thought to be particularly true for composites whichmore » exhibit signific ant microscopic dynamics that can affect macro - scale behavior. We have designed a series of tests to evaluate composite materials under various structural loading conditions with a consistent thermal condition. We have measured mass - loss , heat flux, and temperature throughout the experiments. Several types of panels have been tested, including simple composite panels, and sandwich panels. The main objective of the testing was to understand the importance of the structural loading on a composite to its b ehavior in response to fire - like conditions. During flaming combustion at early times, there are some features of the panel decomposition that are unique to the type of loading imposed on the panels. At load levels tested, fiber reaction rates at later t imes appear to be independent of the initial structural loading.« less

A general panel sizing computer code and its application to composite structural panels

NASA Technical Reports Server (NTRS)

Anderson, M. S.; Stroud, W. J.

1978-01-01

A computer code for obtaining the dimensions of optimum (least mass) stiffened composite structural panels is described. The procedure, which is based on nonlinear mathematical programming and a rigorous buckling analysis, is applicable to general cross sections under general loading conditions causing buckling. A simplified method of accounting for bow-type imperfections is also included. Design studies in the form of structural efficiency charts for axial compression loading are made with the code for blade and hat stiffened panels. The effects on panel mass of imperfections, material strength limitations, and panel stiffness requirements are also examined. Comparisons with previously published experimental data show that accounting for imperfections improves correlation between theory and experiment.

Buckling and postbuckling of composite panels with cutouts subjected to combined edge shear and temperature change

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Kim, Yong H.

1995-01-01

The results of a detailed study of the buckling and postbuckling responses of composite panels with central circular cutouts are presented. The panels are subjected to combined edge shear and temperature change. The panels are discretized by using a two-field degenerate solid element with each of the displacement components having a linear variation throughout the thickness of the panel. The fundamental unknowns consist of the average mechanical strains through the thickness and the displacement components. The effects of geometric nonlinearities and laminated anisotropic material behavior are included. The stability boundary, postbuckling response and the hierarchical sensitivity coefficients are evaluated. The hierarchical sensitivity coefficients measure the sensitivity of the buckling and postbuckling responses to variations in the panel stiffnesses, and the material properties of both the individual layers and the constituents (fibers and matrix). Numerical results are presented for composite panels with central circular cutouts subjected to combined edge shear and temperature change, showing the effects of variations in the hole diameter, laminate stacking sequence and fiber orientation, on the stability boundary and postbuckling response and their sensitivity to changes in the various panel parameters.

Discontinuously Stiffened Composite Panel under Compressive Loading

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Rivers, James M.; Chamis, Christos C.; Murthy, Pappu L. N.

1995-01-01

The design of composite structures requires an evaluation of their safety and durability under service loads and possible overload conditions. This paper presents a computational tool that has been developed to examine the response of stiffened composite panels via the simulation of damage initiation, growth, accumulation, progression, and propagation to structural fracture or collapse. The structural durability of a composite panel with a discontinuous stiffener is investigated under compressive loading induced by the gradual displacement of an end support. Results indicate damage initiation and progression to have significant effects on structural behavior under loading. Utilization of an integrated computer code for structural durability assessment is demonstrated.

Buckling of a Longitudinally Jointed Curved Composite Panel Arc Segment for Next Generation of Composite Heavy Lift Launch Vehicles: Verification Testing Analysis

NASA Technical Reports Server (NTRS)

Farrokh, Babak; Segal, Kenneth N.; Akkerman, Michael; Glenn, Ronald L.; Rodini, Benjamin T.; Fan, Wei-Ming; Kellas, Sortiris; Pineda, Evan J.

2014-01-01

In this work, an all-bonded out-of-autoclave (OoA) curved longitudinal composite joint concept, intended for use in the next generation of composite heavy lift launch vehicles, was evaluated and verified through finite element (FE) analysis, fabrication, testing, and post-test inspection. The joint was used to connect two curved, segmented, honeycomb sandwich panels representative of a Space Launch System (SLS) fairing design. The overall size of the resultant panel was 1.37 m by 0.74 m (54 in by 29 in), of which the joint comprised a 10.2 cm (4 in) wide longitudinal strip at the center. NASTRAN and ABAQUS were used to perform linear and non-linear analyses of the buckling and strength performance of the jointed panel. Geometric non-uniformities (i.e., surface contour imperfections) were measured and incorporated into the FE model and analysis. In addition, a sensitivity study of the specimens end condition showed that bonding face-sheet doublers to the panel's end, coupled with some stress relief features at corner-edges, can significantly reduce the stress concentrations near the load application points. Ultimately, the jointed panel was subjected to a compressive load. Load application was interrupted at the onset of buckling (at 356 kN 80 kips). A post-test non-destructive evaluation (NDE) showed that, as designed, buckling occurred without introducing any damage into the panel or the joint. The jointed panel was further capable of tolerating an impact damage to the same buckling load with no evidence of damage propagation. The OoA cured all-composite joint shows promise as a low mass factory joint for segmented barrels.

Novel Composites for Wing and Fuselage Applications: Speedy Nonlinear Analysis of Postbuckled Panels in Shear (SNAPPS)

NASA Technical Reports Server (NTRS)

Sharp, Dave; Sobel, Larry

1997-01-01

A simple and rapid analysis method, consisting of a number of modular, 'strength-of-materials-type' models, is presented for predicting the nonlinear response and stiffener separation of postbuckled, flat, composite, shear panels. The analysis determines the maximum principal tensile stress in the skin surface layer under to toe. Failure is said to occur when this stress reaches the mean transverse tensile strength of the layer. The analysis methodology consists of a number of closed-form equations that can easily be used in a 'hand analysis. For expediency, they have been programmed into a preliminary design code called SNAPPS (Speedy Nonlinear Analysis of Postbuckled Panels in Shear), which rapidly predicts postbuckling response of the panel for each value of the applied shear load. SNAPPS response and failure predictions were found to agree well with test results for three panels with widely different geometries, laminates and stiffnesses. Design guidelines are given for increasing the load-carrying capacity of stiffened, composite shear panels.

Characterization of the Acoustic Radiation Properties of Laminated and Sandwich Composite Panels in Thermal Environment

NASA Astrophysics Data System (ADS)

Sharma, Nitin; Ranjan Mahapatra, Trupti; Panda, Subrata Kumar; Sahu, Pruthwiraj

2018-03-01

In this article, the acoustic radiation characteristics of laminated and sandwich composite spherical panels subjected to harmonic point excitation under thermal environment are investigated. The finite element (FE) simulation model of the vibrating panel structure is developed in ANSYS using ANSYS parametric design language (APDL) code. Initially, the critical buckling temperatures of the considered structures are obtained and the temperature loads are assorted accordingly. Then, the modal analysis of the thermally stressed panels is performed and the thermo-elastic free vibration responses so obtained are validated with the benchmark solutions. Subsequently, an indirect boundary element (BE) method is utilized to conduct a coupled FE-BE analysis to compute the sound radiation properties of panel structure. The agreement of the present sound power responses with the existing results available in the published literature establishes the validity of the proposed scheme. Finally, the current standardised scheme is extended to solve several numerical examples to bring out the influence of various parameters on the thermo-acoustic characteristics of laminated composite panels.

Nondestructive evaluation and characterization of damage and repair to continuous-fiber ceramic composite panels.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, J. G.; Petrak, D. R.; Pillai, T. A. K.

1998-04-01

Continuous fiber ceramic matrix composites are currently being developed for a variety of high-temperature applications. Because of the high costs of making these components, minor damage incurred during manufacturing or operation must be rewired in order to extend the life of the components. In this study, five ceramic-grade Nicalon{trademark} fiber/SiNC-matrix composite panels were intentionally damaged with a pendulum-type impactor during an impact test. The damaged panels were then repaired at Dow Corning Corporation. Three nondestructive evaluation (NDE) methods were used to study the characteristics of the panels after the damage and again after the panels were repaired. The NDE methodsmore » were X-ray radiography, infrared thermal imaging, and air-coupled ultrasound. The results showed that the impact test induced various types of damage in the panels. The NDE data that were obtained by the three NDE methods were correlated with each other.« less

COMMAND: A FORTRAN program for simplified composite analysis and design. [computerized design of multilayered composite panels

NASA Technical Reports Server (NTRS)

Vanderplaats, G. N.

1976-01-01

A FORTRAN program is presented for preliminary analysis and design of multilayered composite panels subjected to inplane loads. All plys are of the same material. The composite is assumed symmetric about the midplane, but need not be balanced. Failure criterion includes limit ply strains and lower bounds on composite inplane stiffnesses. Multiple load conditions are considered. The required input data is defined and examples are provided to aid the use in making the program operational. Average panel design times are two seconds on an IBM 360/67 computer. Results are compared with published literature. A complete FORTRAN listing of program COMAND is provided. In addition, the optimization program CONMIN is required for design.

34 CFR 350.52 - What is the composition of a peer review panel?

Code of Federal Regulations, 2013 CFR

2013-07-01

... panel will consider; (ii) The roles of potential panel members in those activities; and (iii) The... Department. (4) Whether the panel includes knowledgeable individuals with disabilities, or parents, family...

34 CFR 350.52 - What is the composition of a peer review panel?

Code of Federal Regulations, 2012 CFR

2012-07-01

... panel will consider; (ii) The roles of potential panel members in those activities; and (iii) The... Department. (4) Whether the panel includes knowledgeable individuals with disabilities, or parents, family...

34 CFR 350.52 - What is the composition of a peer review panel?

Code of Federal Regulations, 2014 CFR

2014-07-01

... panel will consider; (ii) The roles of potential panel members in those activities; and (iii) The... Department. (4) Whether the panel includes knowledgeable individuals with disabilities, or parents, family...

Comparison of Wood Composite Properties Using Cantilever-Beam Bending

Treesearch

Houjiang Zhang; John F. Hunt; Lujing Zhou

2015-01-01

Wood-based composite panels generally are first tested out-of-plane in the primarypanel directionfollowed by the cross panel direction, but rarely edgewise. While most applications use wood-based composites in the flat-wise orientation and only need the out-of-plane properties, there are construction configurations where edgewise properties are needed for improved...

Acousto-ultrasonic decay in metal matrix composite panels

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1995-01-01

Acousto-ultrasonic (A-U) decay rates (UD) were measured in metal matrix composite (MMC) panels. The MMC panels had fiber architectures and cross-sectional thicknesses corresponding to those designed for aerospace turbine engine structures. The wavelength-to-thickness ratio produced by the combination of experimental frequency setting conditions and specimen geometry was found to be a key parameter for identifying optimum conditions for UD measurements. The ratio was shown to be a useful rule of thumb when applied to ceramic matrix composites (CMC)s and monolithic thermo-plastics.

Two-Dimensional Sequential and Concurrent Finite Element Analysis of Unstiffened and Stiffened Aluminum and Composite Panels with Hole

NASA Technical Reports Server (NTRS)

Razzaq, Zia; Prasad, Venkatesh

1988-01-01

The results of a detailed investigation of the distribution of stresses in aluminum and composite panels subjected to uniform end shortening are presented. The focus problem is a rectangular panel with two longitudinal stiffeners, and an inner stiffener discontinuous at a central hole in the panel. The influence of the stiffeners on the stresses is evaluated through a two-dimensional global finite element analysis in the absence or presence of the hole. Contrary to the physical feel, it is found that the maximum stresses from the glocal analysis for both stiffened aluminum and composite panels are greater than the corresponding stresses for the unstiffened panels. The inner discontinuous stiffener causes a greater increase in stresses than the reduction provided by the two outer stiffeners. A detailed layer-by-layer study of stresses around the hole is also presented for both unstiffened and stiffened composite panels. A parallel equation solver is used for the global system of equations since the computational time is far less than that using a sequential scheme. A parallel Choleski method with up to 16 processors is used on Flex/32 Multicomputer at NASA Langley Research Center. The parallel computing results are summarized and include the computational times, speedups, bandwidths, and their inter-relationships for the panel problems. It is found that the computational time for the Choleski method decreases with a decrease in bandwidth, and better speedups result as the bandwidth increases.

Acoustically Tailored Composite Rotorcraft Fuselage Panels

DTIC Science & Technology

2015-07-02

In this work, we have developed and demonstrated technologies and methodologies for designing composite fuselage panels which radiate less sound...SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) NASA Langley Rsearch Center ATTN: Mr. Noah Schiller Structural Acoustics Branch Mail Stop 463 Hampton...500 Hz. The panels were designed to withstand structural loading from normal rotorcraft operation, as well as ’man-on-the-roof static loads

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Mardoian, G. H.; Ezzo, M. B.

1986-01-01

This report presents an assessment of composite helicopter tail rotor spars and horizontal stabilizers, exposed to the effects of the environment, after up to five and a half years of commercial service. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since September 1979. Full scale static and fatigue tests have been conducted on graphite/epoxy and Kevlar/epoxy composite components obtained from Sikorsky Model S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale static and fatigue tests are being conducted on coupons obtained from panels under exposure to outdoor conditions in Stratford, Connecticut and West Palm, Florida. The panel layups are representative of the S-76 components. Additionally, this report discusses the results of moisture absorption evaluations and strength tests on the S-76 components and composite panels with up to five years of outdoor exposure.

Nanoparticle Filtration in a RTM Processed Epoxy/Carbon Fiber Composite

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Micham, Logan; Copa, Christine C.; Criss, James M., Jr.; Mintz, Eric A.

2011-01-01

Several epoxy matrix composite panels were fabricated by resin transfer molding (RTM) E862/W resin onto a triaxially braided carbon fiber pre-form. Nanoparticles including carbon nanofiber, synthetic clay, and functionalized graphite were dispersed in the E862 matrix, and the extent of particle filtration during processing was characterized. Nanoparticle dispersion in the resin flashing on both the inlet and outlet edges of the panel was compared by TEM. Variation in physical properties such as Tg and moisture absorption throughout the panel were also characterized. All nanoparticle filled panels showed a decrease in Tg along the resin flow path across the panel, indicating nanoparticle filtration, however there was little change in moisture absorption. This works illustrates the need to obtain good nano-particle dispersion in the matrix resin to prevent particle agglomeration and hence particle filtration in the resultant polymer matrix composites (PMC).

Comparison of hand laid-up tape and filament wound composite cylinders and panels with and without impact damage

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Lopez, Osvaldo F.

1991-01-01

Experimentally determined axial compressive failure loads, strains and failure modes of composite flat panels and cylinders are presented. A comparison of two types of filament wound flat graphite-epoxy panels indicates that the winding pattern can influence structural response. A comparison of hand laid-up tape and filament wound composite cylinders indicates that fabrication method may not significantly influence the failure mode or average failure strain of thick-walled (radius-to-thickness ratio less than 15) graphite-epoxy cylinders. The interaction of manufacturing-induced features (fiber cross-overs) and low-speed impact damage for graphite-epoxy specimens is also presented. Filament would flat panels with many fiber cross-overs exhibited lower failure strains than filament wound panels without fiber cross-overs for all impact speeds examined. Graphite-thermoplastic cylinders exhibited a significantly different failure mode from the graphite-epoxy cylinders.

A Spectral Analysis Approach for Acoustic Radiation from Composite Panels

NASA Technical Reports Server (NTRS)

Turner, Travis L.; Singh, Mahendra P.; Mei, Chuh

2004-01-01

A method is developed to predict the vibration response of a composite panel and the resulting far-field acoustic radiation due to acoustic excitation. The acoustic excitation is assumed to consist of obliquely incident plane waves. The panel is modeled by a finite element analysis and the radiated field is predicted using Rayleigh's integral. The approach can easily include other effects such as shape memory alloy (SMA) ber reinforcement, large detection thermal postbuckling, and non-symmetric SMA distribution or lamination. Transmission loss predictions for the case of an aluminum panel excited by a harmonic acoustic pressure are shown to compare very well with a classical analysis. Results for a composite panel with and without shape memory alloy reinforcement are also presented. The preliminary results demonstrate that the transmission loss can be significantly increased with shape memory alloy reinforcement. The mechanisms for further transmission loss improvement are identified and discussed.

Flight service evaluation of PRD-49/epoxy composite panels in wide-bodied commercial transport aircraft

NASA Technical Reports Server (NTRS)

Wooley, J. H.

1974-01-01

Fairing panels were fabricated to evaluate the fabrication characteristics and flight service performance of PRD-49 (Kevlar-49) a composite reinforcing material and to compare it with the fiberglass which is currently in use. Panel configurations were selected to evaluate the PRD-49 with two resin matrix materials in sandwich and solid laminate construction. Left and right hand versions of these configurations were installed on L-1011's which will accumulate approximately 3000 flight hours per year per aircraft. The direct substitution of PRD-49 for fiberglass produced a twenty-six percent weight reduction on the panel configurations. Examination of these panels revealed that there was no visible difference between the PRD-49 and adjacent fiberglass panels.

Advanced composites in Japan

NASA Technical Reports Server (NTRS)

Diefendorf, R. Judd; Hillig, William G.; Grisaffe, Salvatore J.; Pipes, R. Byron; Perepezko, John H.; Sheehan, James E.

1994-01-01

The JTEC Panel on Advanced Composites surveyed the status and future directions of Japanese high-performance ceramic and carbon fibers and their composites in metal, intermetallic, ceramic, and carbon matrices. Because of a strong carbon and fiber industry, Japan is the leader in carbon fiber technology. Japan has initiated an oxidation-resistant carbon/carbon composite program. With its outstanding technical base in carbon technology, Japan should be able to match present technology in the U.S. and introduce lower-cost manufacturing methods. However, the panel did not see any innovative approaches to oxidation protection. Ceramic and especially intermetallic matrix composites were not yet receiving much attention at the time of the panel's visit. There was a high level of monolithic ceramic research and development activity. High temperature monolithic intermetallic research was just starting, but notable products in titanium aluminides had already appeared. Matrixless ceramic composites was one novel approach noted. Technologies for high temperature composites fabrication existed, but large numbers of panels or parts had not been produced. The Japanese have selected aerospace as an important future industry. Because materials are an enabling technology for a strong aerospace industry, Japan initiated an ambitious long-term program to develop high temperature composites. Although just starting, its progress should be closely monitored in the U.S.

In-Plane Cracking Behavior and Ultimate Strength for 2D Woven and Braided Melt-Infiltrated SiC/SiC Composites Tensile Loaded in Off-Axis Fiber Directions

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.; Yun, Hee Mann; DiCarlo, James A.

2007-01-01

The tensile mechanical properties of ceramic matrix composites (CMC) in directions off the primary axes of the reinforcing fibers are important for architectural design of CMC components that are subjected to multi-axial stress states. In this study, 2D-woven melt-infiltrated (MI) SiC/SiC composite panels with balanced fiber content in the 0 degree and 90 degree directions were tensile loaded in-plane in the 0 degree direction and at 45 degree to this direction. In addition, a 2D triaxially-braided MI composite panel with balanced fiber content in the plus or minus 67 degree bias directions and reduced fiber content in the axial direction was tensile loaded perpendicular to the axial direction tows (i.e., 23 degrees from the bias fibers). Stress-strain behavior, acoustic emission, and optical microscopy were used to quantify stress-dependent matrix cracking and ultimate strength in the panels. It was observed that both off-axis loaded panels displayed higher composite onset stresses for through-thickness matrix cracking than the 2D-woven 0/90 panels loaded in the primary 0 degree direction. These improvements for off-axis cracking strength can in part be attributed to higher effective fiber fractions in the loading direction, which in turn reduces internal stresses on critical matrix flaws for a given composite stress. Also for the 0/90 panel loaded in the 45 degree direction, an improved distribution of matrix flaws existed due to the absence of fiber tows perpendicular to the loading direction. In addition, for the +67/0/-67 braided panel, the axial tows perpendicular to the loading direction were not only low in volume fraction, but were also were well separated from one another. Both off-axis oriented panels also showed relatively good ultimate tensile strength when compared to other off-axis oriented composites in the literature, both on an absolute strength basis as well as when normalized by the average fiber strength within the composites. Initial implications are discussed for constituent and architecture design to improve the directional cracking of SiC/SiC CMC components with MI matrices.

Experimental and theoretical modal analysis of full-sized wood composite panels supported on four nodes

Treesearch

Cheng Guan; Houjiang Zhang; Xiping Wang; Hu Miao; Lujing Zhou; Fenglu Liu

2017-01-01

Key elastic properties of full-sized wood composite panels (WCPs) must be accurately determined not only for safety, but also serviceability demands. In this study, the modal parameters of full-sized WCPs supported on four nodes were analyzed for determining the modulus of elasticity (E) in both major and minor axes, as well as the in-plane shear modulus of panels by...

Fatigue evaluation of composite-reinforced, integrally stiffened metal panels

NASA Technical Reports Server (NTRS)

Dumesnil, C. E.

1973-01-01

The fatigue behavior of composite-reinforced, integrally stiffened metal panels was investigated in combined metal and composite materials subjected to fatigue loading. The systems investigated were aluminum-graphite/epoxy, and aluminum-S glass/epoxy. It was found that the composite material would support the total load at limit stress after the metal had completely failed, and the weight of the composite-metal system would be equal to that of an all metal system which would carry the same total load at limit stress.

A loading study of older highway bridges in Virginia. Pt. 2, Concrete slab and steel beam bridge in Clarke County.

DOT National Transportation Integrated Search

1976-01-01

A 60-foot non-composite steel beam and concrete deck highway bridge span over the Shenandoah River on Route 7 in Clarke County was tested with a 23-ton, tandem axle test vehicle in July1975. Strain gages were placed near midspan on the lower flanges,...

Concept Development Modular Hybrid Pier (MHP)

DTIC Science & Technology

2000-02-01

rated FRP composite bridge or bridge deck is commercially available from Creative Pultrusions, Kansas Structural Systems, Martin - Marietta , Hardcore...NAVAL FACILITIES ENGINEERING SERVICE CENTER Port Hueneme, California 93043-4370 Contract Report CR 00-001-SHR FINAL REPORT PHASE 1 - CONCEPT...20000301 043 Approved for public release; distribution is unlimited. DTIC QUALITY IMWSOfBD 4 ^^ Printed on recycled paper REPORT DOCUMENTATION PAGE

Connecticut permanent long-term bridge monitoring network, volume 6 : monitoring of a continuous plate girder bridge with load restrictions - Route 15 over the Housatonic River in Stratford (Bridge #761).

DOT National Transportation Integrated Search

2014-08-01

This report describes the instrumentation and data acquisition system for monitoring of a continuous span steel plate : girder bridge with a composite concrete deck located on a limited access highway. The monitoring system was : developed and instal...

Blast protection of infrastructure using advanced composites

NASA Astrophysics Data System (ADS)

Brodsky, Evan

This research was a systematic investigation detailing the energy absorption mechanisms of an E-glass web core composite sandwich panel subjected to an impulse loading applied orthogonal to the facesheet. Key roles of the fiberglass and polyisocyanurate foam material were identified, characterized, and analyzed. A quasi-static test fixture was used to compressively load a unit cell web core specimen machined from the sandwich panel. The web and foam both exhibited non-linear stress-strain responses during axial compressive loading. Through several analyses, the composite web situated in the web core had failed in axial compression. Optimization studies were performed on the sandwich panel unit cell in order to maximize the energy absorption capabilities of the web core. Ultimately, a sandwich panel was designed to optimize the energy dissipation subjected to through-the-thickness compressive loading.

Coir fiber reinforced polypropylene composite panel for automotive interior applications

Treesearch

Nadir Ayrilmis; Songklod Jarusombuti; Vallayuth Fueangvivat; Piyawade Bauchongkol; Robert H. White

2011-01-01

In this study, physical, mechanical, and flammability properties of coconut fiber reinforced polypropylene (PP) composite panels were evaluated. Four levels of the coir fiber content (40, 50, 60, and 70 % based on the composition by weight) were mixed with the PP powder and a coupling agent, 3 wt % maleic anhydride grafted PP (MAPP) powder. The water resistance and the...

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Mardoian, George H.; Ezzo, Maureen B.

1990-01-01

An assessment is presented of ten composite tail rotor spars and four horizontal stabilizers exposed to the effects of in-flight commercial service for up to nine years to establish realistic environmental factors for use in future designs. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since 1979. Full scale static and fatigue tests were conducted on graphite/epoxy and Kevlar/epoxy composite components removed from Sikorsky Model S-76 helicopters in commercial operations off the Gulf Coast of Louisiana. Small scale static and fatigue tests were conducted on coupons obtained from panels exposed to outdoor conditions in Stratford, CT and West Palm Beach, Florida. The panel materials and ply configurations were representative of the S-76 components. The results are discussed of moisture analyses and strength tests on both the S-76 components and composite panels after up to nine years of outdoor exposure. Full scale tests performed on the helicopter components did not disclose any significant reductions from the baseline strengths. The results increased confidence in the long term durability of advanced composite materials in helicopter structural applications.

POSTOP: Postbuckled open-stiffener optimum panels, user's manual

NASA Technical Reports Server (NTRS)

Biggers, S. B.; Dickson, J. N.

1984-01-01

The computer program POSTOP developed to serve as an aid in the analysis and sizing of stiffened composite panels that may be loaded in the postbuckling regime, is intended for the preliminary design of metal or composite panels with open-section stiffeners, subjected to multiple combined biaxial compression (or tension), shear and normal pressure load cases. Longitudinal compression, however, is assumed to be the dominant loading. Temperature, initial bow eccentricity and load eccentricity effects are included. The panel geometry is assumed to be repetitive over several bays in the longitudinal (stiffener) direction as well as in the transverse direction. Analytical routines are included to compute panel stiffnesses, strains, local and panel buckling loads, and skin/stiffener interface stresses. The resulting program is applicable to stiffened panels as commonly used in fuselage, wing, or empennage structures. The capabilities and limitations of the code are described. Instructions required to use the program and several example problems are included.

Dynamic determination of modulus of elasticity of full-size wood composite panels using a vibration method

Treesearch

Cheng Guan; Houjiang Zhang; Lujing Zhou; Xiping Wang

2015-01-01

A vibration testing method based on free vibration theory in a ‘‘free–free” support condition was investigated for evaluating the modulus of elasticity (MOE) of full-size wood composite panels (WCPs). Vibration experiments were conducted on three types of WCPs (medium density fibreboard, particleboard, and plywood) to determine the dynamic MOE of the panels. Static...

Finite Element Modeling of Fragment Penetration of Thin Structural Composite Laminates

DTIC Science & Technology

1991-12-01

his direction and assistance provided during the program. The following are registered trade names: Kevlar-29, 3M Co., Scotchply, Owens Corning Fiberglass...grains, are used. Composite laminates such as Owens Corning Fiberglass (R) panels, 3M Scotchply 1002 (R) panels and Kevlar-29 (R) reinforced plastic...results [2]: 1. Owens Corning Fiberglass (OCF) Structural Panels. Woven S-2 glass and a typical resin type, contert, sizing, and cure cycle at 220

Space environmental effects on LDEF composites: A leading edge coated graphite epoxy panel

NASA Technical Reports Server (NTRS)

George, Pete E.; Dursch, Harry W.; Hill, Sylvester G.

1993-01-01

The electronics module cover for the leading edge (Row D 9) experiment M0003-8 was fabricated from T300 graphite/934 epoxy unidirectional prepreg tape in a (O(sub 2), +/- 45, O(sub 2), +/- 45, 90, 0)(sub s) layup. This 11.75 in x 16.75 in panel was covered with thermal control coatings in three of the four quadrants with the fourth quadrant uncoated. The composite panel experienced different thermal cycling extremes in each quadrant due to the different optical properties of the coatings and bare composite. The panel also experienced ultraviolet (UV) and atomic oxygen (AO) attack as well as micrometeoroid and space debris impacts. An AO reactivity of 0.99 x 10(exp -24) cm(sup 3)/atom was calculated for the bare composite based on thickness loss. The white urethane thermal control coatings (A276 and BMS 1060) prevented AO attack of the composite substrate. However, the black urethane thermal control coating (Z306) was severely eroded by AO, allowing some AO attack of the composite substrate. An interesting banding pattern on the AO eroded bare composite surface was investigated and found to match the dimensions of the graphite fiber tow widths as prepregged. Also, erosion depths were greater in the darker bands. Five micrometeoroid/space debris impacts were cross sectioned to investigate possible structural damage as well as impact/AO interactions. Local crushing and delaminations were found to some extent in all of the impacts. No signs of coating undercutting were observed despite the extensive AO erosion patterns seen in the exposed composite material at the impact sites. An extensive microcrack study was performed on the panel along with modeling of the thermal environment to estimate temperature extremes and thermal shock. The white coated composite substrate displayed almost no microcracking while the black coated and bare composite showed extensive microcracking. Significant AO erosion was seen in many of the cracks in the bare composite.

Warpage of Large Curved Composite Panels due to Manufacturing Anomalies

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr. (Technical Monitor); Ambur, Damadar (Technical Monitor); Ochinero, T. T.; Hyer, M. W.

2002-01-01

This paper discusses the influences of a misaligned layer, a resin-rich slightly thicker layer, and a small thermal gradient on the thermally-induced deformations of large curved composite panels during cooldown from their cure temperature. The deformations represent warpage of the panels due to anomalies that occur during layup, consolidation, and cure. Two-dimensional finite element analyses are used The deformations are categorized as to their impact on circumferential and twist warpage metrics. The results are intended to highlight the sensitivity of manufactured panel shape to the various unwanted effects that can occur during manufacturing.

PERFORMANCE ENHANCEMENT OF COMPRESSION MOLDED KENAF FIBER REINFORCED VINYL ESTER COMPOSITES THROUGH RESIN ADDITIVE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin

2010-05-17

Plant-based bio-fiber has the potential to achieve weight and cost savings over glass fiber in automotive polymer composites if moisture stability and fiber-resin compatibility issues can be solved. This paper describes the compression molding of 50vol% 2 inch random nonwoven mat kenaf fiber vinyl ester composites with and without chemical resin additives intended to improve moisture stability and resin compatibility. The 2wt% addition of n-undecanoyl chloride or 10-undecenoyl chloride to the styrene-based resin prior to molding of the kenaf composites was observed to decrease the 24hr, 25oC moisture uptake of the molded panels by more than 50%. The tensile stiffnessmore » and flexural stiffness of the soaked panels containing these additives were seen to increase by more than 30% and 70%, respectively, relative to panels made with no additives. While ‘dry’ panel (50% relative humidity at 25oC) strengths did not significantly change in the presence of the additives, tensile strength was observed to increase by more than 40% and flexural strength more than doubled for the soaked panels.« less

Light-weight sandwich panel honeycomb core with hybrid carbon-glass fiber composite skin for electric vehicle application

NASA Astrophysics Data System (ADS)

Cahyono, Sukmaji Indro; Widodo, Angit; Anwar, Miftahul; Diharjo, Kuncoro; Triyono, Teguh; Hapid, A.; Kaleg, S.

2016-03-01

The carbon fiber reinforced plastic (CFRP) composite is relative high cost material in current manufacturing process of electric vehicle body structure. Sandwich panels consisting polypropylene (PP) honeycomb core with hybrid carbon-glass fiber composite skin were investigated. The aim of present paper was evaluate the flexural properties and bending rigidity of various volume fraction carbon-glass fiber composite skins with the honeycomb core. The flexural properties and cost of panels were compared to the reported values of solid hybrid Carbon/Glass FRP used for the frame body structure of electric vehicle. The finite element model of represented sandwich panel was established to characterize the flexural properties of material using homogenization technique. Finally, simplified model was employed to crashworthiness analysis for engine hood of the body electric vehicle structure. The good cost-electiveness of honeycomb core with hybrid carbon-glass fiber skin has the potential to be used as a light-weight alternative material in body electric vehicle fabricated.

46 CFR 69.109 - Under-deck tonnage.

Code of Federal Regulations, 2012 CFR

2012-10-01

...” means the tonnage of the space below the line of the tonnage deck, as that volume is calculated under... deck from the keel. Only decks without openings that permit space below to be exempt from inclusion in....) Spaces between the line of the tonnage deck and the higher portions of that deck are not included in...

46 CFR 69.109 - Under-deck tonnage.

Code of Federal Regulations, 2014 CFR

2014-10-01

...” means the tonnage of the space below the line of the tonnage deck, as that volume is calculated under... deck from the keel. Only decks without openings that permit space below to be exempt from inclusion in....) Spaces between the line of the tonnage deck and the higher portions of that deck are not included in...

46 CFR 69.109 - Under-deck tonnage.

Code of Federal Regulations, 2013 CFR

2013-10-01

...” means the tonnage of the space below the line of the tonnage deck, as that volume is calculated under... deck from the keel. Only decks without openings that permit space below to be exempt from inclusion in....) Spaces between the line of the tonnage deck and the higher portions of that deck are not included in...

46 CFR 69.109 - Under-deck tonnage.

Code of Federal Regulations, 2011 CFR

2011-10-01

...” means the tonnage of the space below the line of the tonnage deck, as that volume is calculated under... deck from the keel. Only decks without openings that permit space below to be exempt from inclusion in....) Spaces between the line of the tonnage deck and the higher portions of that deck are not included in...

46 CFR 178.450 - Calculation of drainage area for cockpit and well deck vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... PASSENGER VESSELS (UNDER 100 GROSS TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178... × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (BR × DR) − VR BR...

46 CFR 178.450 - Calculation of drainage area for cockpit and well deck vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PASSENGER VESSELS (UNDER 100 GROSS TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178... × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (BR × DR) − VR BR...

46 CFR 178.450 - Calculation of drainage area for cockpit and well deck vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... PASSENGER VESSELS (UNDER 100 GROSS TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178... × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (BR × DR) − VR BR...

46 CFR 178.450 - Calculation of drainage area for cockpit and well deck vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... PASSENGER VESSELS (UNDER 100 GROSS TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178... × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (BR × DR) − VR BR...

46 CFR 178.450 - Calculation of drainage area for cockpit and well deck vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PASSENGER VESSELS (UNDER 100 GROSS TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178... × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (BR × DR) − VR BR...

Behaviour of partially composite precast concrete sandwich panels under flexural and axial loads

NASA Astrophysics Data System (ADS)

Tomlinson, Douglas George

Precast concrete sandwich panels are commonly used on building exteriors. They are typically composed of two concrete wythes that surround rigid insulation. They are advantageous as they provide both structural and thermal resistance. The structural response of sandwich panels is heavily influenced by shear connectors that link the wythes together. This thesis presents a study on partially composite non-prestressed precast concrete wall panels. Nine flexure tests were conducted on a wall design incorporating 'floating' concrete studs and Glass Fibre Reinforced Polymer (GFRP) connectors. The studs encapsulate and stiffen the connectors, reducing shear deformations. Ultimate loads increased from 58 to 80% that of a composite section as the connectors' reinforcement ratio increased from 2.6 to 9.8%. This design was optimized by reinforcing the studs and integrating them with the structural wythe; new connectors composed of angled steel or Basalt-FRP (BFRP) were used. The load-slip response of the new connector design was studied through 38 double shear push-through tests using various connector diameters and insertion angles. Larger connectors were stronger but more likely to pull out. Seven flexure tests were conducted on the new wall design reinforced with different combinations of steel and BFRP connectors and reinforcement. Composite action varied from 50 to 90% depending on connector and reinforcement material. Following this study, the axial-bending interaction curves were established for the new wall design using both BFRP and steel connectors and reinforcement. Eight panels were axially loaded to predesignated loads then loaded in flexure to failure. A technique is presented to experimentally determine the effective centroid of partially composite sections. Beyond the tension and compression-controlled failure regions of the interaction curve, a third region was observed in between, governed by connector failure. Theoretical models were developed for the bond-slip behaviour of the shear connection and to analyze the full panel's flexural and axial response to determine the longitudinal shear force transferred between wythes and account for partial composite behavior. The models were validated against experiments and used to conduct a parametric study. Among several interesting findings, the study demonstrated how composite action increases with the slenderness of axially loaded panels.

46 CFR 116.1110 - Drainage of flush deck vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ARRANGEMENT Drainage and Watertight Integrity of Weather Decks § 116.1110 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be...

46 CFR 178.430 - Drainage of well deck vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.430 Drainage of well deck vessels. (a) The weather deck on a well deck vessel must be watertight. (b) The area required on a well...

46 CFR 116.1110 - Drainage of flush deck vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ARRANGEMENT Drainage and Watertight Integrity of Weather Decks § 116.1110 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be...

46 CFR 178.430 - Drainage of well deck vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.430 Drainage of well deck vessels. (a) The weather deck on a well deck vessel must be watertight. (b) The area required on a well...

46 CFR 178.410 - Drainage of flush deck vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.410 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel...

46 CFR 178.430 - Drainage of well deck vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.430 Drainage of well deck vessels. (a) The weather deck on a well deck vessel must be watertight. (b) The area required on a well...

46 CFR 178.430 - Drainage of well deck vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.430 Drainage of well deck vessels. (a) The weather deck on a well deck vessel must be watertight. (b) The area required on a well...

46 CFR 178.410 - Drainage of flush deck vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.410 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel...

46 CFR 116.1110 - Drainage of flush deck vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ARRANGEMENT Drainage and Watertight Integrity of Weather Decks § 116.1110 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be...

46 CFR 178.410 - Drainage of flush deck vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.410 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel...

46 CFR 178.410 - Drainage of flush deck vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.410 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel...

46 CFR 116.1110 - Drainage of flush deck vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ARRANGEMENT Drainage and Watertight Integrity of Weather Decks § 116.1110 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be...

46 CFR 178.430 - Drainage of well deck vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.430 Drainage of well deck vessels. (a) The weather deck on a well deck vessel must be watertight. (b) The area required on a well...

46 CFR 178.410 - Drainage of flush deck vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.410 Drainage of flush deck vessels. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel...

Deficits in emotion based decision-making in schizophrenia; a new insight based on the Iowa Gambling Task.

PubMed

Matsuzawa, Daisuke; Shirayama, Yukihiko; Niitsu, Tomihisa; Hashimoto, Kenji; Iyo, Masaomi

2015-03-03

Defective decision-making is a symptom of impaired cognitive function observed in patients with schizophrenia. Impairment on the Iowa Gambling Task (IGT) has been reported in patients with schizophrenia, but these results are inconsistent among studies. We differentiated subjects based on whether they expressed certainty at having deciphered an advantageous strategy in the course of the task. We investigated this impairment using the IGT in patients with schizophrenia and performed analysis different to standard advantageous decks minus disadvantageous decks in all 100 card choices, [C+D]-[A+B](1-100). We examined the effects on behavior after receiving a big penalty. Results were dependent on participants utilizing with or without certainty, the best strategy for positive gain. Schizophrenic patients without certainty failed to show card choice shift, from disadvantageous to advantageous decks. Differences in card choices on the IGT were clearly shown between patients with schizophrenia and normal controls by the use of improvement from block 1 to blocks 3-5, [C+D]-[A+B]([41-100]-[1-20]) (P<0.001), rather than by the composite value of blocks 3-5, [C+D]-[A+B](41-100) (P=0.011). The deficit of emotion-based learning in schizophrenia without uncertainty were related to scores on the SANS and S5 attention. In addition, S1 affective flattering and S4 anhedonia-asociality were also related to these deficits. For a while, normal controls showed a smooth shift from disadvantageous to advantageous decks after big penalties, with or without a certainty for strategy. However, patients with schizophrenia failed to show switching from disadvantageous to advantageous decks, even after big penalties, under the same conditions. Our results highlight certainty of strategy and behavior after a big penalty, as two points of difference between patients with schizophrenia and normal controls in the accumulation of net scores. Copyright © 2014 Elsevier Inc. All rights reserved.

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Rich, M. J.; Lowry, D. W.

1983-01-01

This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Rich, M. J.; Lowry, D. W.

1982-01-01

This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

Buffer strips in composites at elevated temperature

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1983-01-01

The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.

Damage Characteristics and Residual Strength of Composite Sandwich Panels Impacted with and Without Compression Loading

NASA Technical Reports Server (NTRS)

McGowan, David M.; Ambur, Damodar R.

1998-01-01

The results of an experimental study of the impact damage characteristics and residual strength of composite sandwich panels impacted with and without a compression loading are presented. Results of impact damage screening tests conducted to identify the impact-energy levels at which damage initiates and at which barely visible impact damage occurs in the impacted facesheet are discussed. Parametric effects studied in these tests include the impactor diameter, dropped-weight versus airgun-launched impactors, and the effect of the location of the impact site with respect to the panel boundaries. Residual strength results of panels tested in compression after impact are presented and compared with results of panels that are subjected to a compressive preload prior to being impacted.

Construction of crack-free bridge decks : technical summary.

DOT National Transportation Integrated Search

2017-04-01

The report documents the performance of the decks based on crack surveys performed on the LC-HPC decks and : matching control bridge decks. The specifications for LC-HPC bridge decks, which cover aggregates, concrete, : and construction procedures, a...

46 CFR 171.140 - Drainage of a flush deck vessel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.140 Drainage of a flush deck vessel. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must...

46 CFR 171.140 - Drainage of a flush deck vessel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.140 Drainage of a flush deck vessel. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must...

46 CFR 171.140 - Drainage of a flush deck vessel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.140 Drainage of a flush deck vessel. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must...

46 CFR 171.140 - Drainage of a flush deck vessel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.140 Drainage of a flush deck vessel. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must...

46 CFR 171.140 - Drainage of a flush deck vessel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.140 Drainage of a flush deck vessel. (a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must...

The Design, Fabrication, and Testing of Composite Heat Exchange Coupons

NASA Technical Reports Server (NTRS)

Quade, Derek J.; Meador, Michael A.; Shin, Euy-Sik; Johnston, James C.; Kuczmarski, Maria A.

2011-01-01

Several heat exchanger (HX) test panels were designed, fabricated and tested at the NASA Glenn Research Center to explore the fabrication and performance of several designs for composite heat exchangers. The development of these light weight, high efficiency air-liquid test panels was attempted using polymer composites and carbon foam materials. The fundamental goal of this effort was to demonstrate the feasibility of the composite HX for various space exploration and thermal management applications including Orion CEV and Altair. The specific objectives of this work were to select optimum materials, designs, and to optimize fabrication procedures. After fabrication, the individual design concept prototypes were tested to determine their thermal performance and to guide the future development of full-size engineering development units (EDU). The overall test results suggested that the panel bonded with pre-cured composite laminates to KFOAM Grade L1 scored above the other designs in terms of ease of manufacture and performance.

Active cooling of microvascular composites for battery packaging

NASA Astrophysics Data System (ADS)

Pety, Stephen J.; Chia, Patrick X. L.; Carrington, Stephen M.; White, Scott R.

2017-10-01

Batteries in electric vehicles (EVs) require a packaging system that provides both thermal regulation and crash protection. A novel packaging scheme is presented that uses active cooling of microvascular carbon fiber reinforced composites to accomplish this multifunctional objective. Microvascular carbon fiber/epoxy composite panels were fabricated and their cooling performance assessed over a range of thermal loads and experimental conditions. Tests were performed for different values of coolant flow rate, channel spacing, panel thermal conductivity, and applied heat flux. More efficient cooling occurs when the coolant flow rate is increased, channel spacing is reduced, and thermal conductivity of the host composite is increased. Computational fluid dynamics (CFD) simulations were also performed and correlate well with the experimental data. CFD simulations of a typical EV battery pack confirm that microvascular composite panels can adequately cool battery cells generating 500 W m-2 heat flux below 40 °C.

DORMAN computer program (study 2.5). Volume 3: Original data bank listing. [development of data bank for computerized information storage of NASA programs

NASA Technical Reports Server (NTRS)

Stricker, L. T.

1973-01-01

A number of analyses have been performed using the DORCA program for several NASA-funded Aerospace Corporation studies in the past few years. The data decks containing the input data for these analyses have been compiled and are submitted, under separate cover. A few of the data decks are full (basic) decks containing every data item and are used as reference decks in the data bank. The other data decks were obtained by differencing a full deck with respect to one of the reference decks. Using the DORMAN program, a full deck can be recreated from the modified deck and its reference deck when and if desired. The content and structure of the data bank are described. A description of each of these data decks is presented. Three of the cases that are included in this volume have become so widely recognized and accepted that additional descriptive material has been provided. The three cases are: Case 500 Costs, Case 506 Costs, and Case 403.

ACT Payload Shroud Structural Concept Analysis and Optimization

NASA Technical Reports Server (NTRS)

Zalewski, Bart B.; Bednarcyk, Brett A.

2010-01-01

Aerospace structural applications demand a weight efficient design to perform in a cost effective manner. This is particularly true for launch vehicle structures, where weight is the dominant design driver. The design process typically requires many iterations to ensure that a satisfactory minimum weight has been obtained. Although metallic structures can be weight efficient, composite structures can provide additional weight savings due to their lower density and additional design flexibility. This work presents structural analysis and weight optimization of a composite payload shroud for NASA s Ares V heavy lift vehicle. Two concepts, which were previously determined to be efficient for such a structure are evaluated: a hat stiffened/corrugated panel and a fiber reinforced foam sandwich panel. A composite structural optimization code, HyperSizer, is used to optimize the panel geometry, composite material ply orientations, and sandwich core material. HyperSizer enables an efficient evaluation of thousands of potential designs versus multiple strength and stability-based failure criteria across multiple load cases. HyperSizer sizing process uses a global finite element model to obtain element forces, which are statistically processed to arrive at panel-level design-to loads. These loads are then used to analyze each candidate panel design. A near optimum design is selected as the one with the lowest weight that also provides all positive margins of safety. The stiffness of each newly sized panel or beam component is taken into account in the subsequent finite element analysis. Iteration of analysis/optimization is performed to ensure a converged design. Sizing results for the hat stiffened panel concept and the fiber reinforced foam sandwich concept are presented.

Method of Making a Composite Panel Having Subsonic Transverse Wave Speed Characteristics

NASA Technical Reports Server (NTRS)

Palumbo, Daniel L. (Inventor); Klos, Jacob (Inventor)

2012-01-01

A method of making a composite panel having subsonic transverse wave speed characteristics which has first and second sheets sandwiching a core with at least one of the sheets being attached to the core at first regions thereof and unattached to the core at second regions thereof.

Spartan Auxiliary Mount Panel (SPAM): A Metal Matrix Composite Honeycomb Panel for Space Flight Use

NASA Technical Reports Server (NTRS)

Segal, Kenneth N.; Stevens, Edward J.

1998-01-01

This presentation focus on the use of metal matrix composite (MMC) material option in spaceflight hardware applications. It addresses the important questions and issues such as: what is SPAM; why the use of MMC; design requirements and flexibility; qualification testing; and flight concerns.

Free vibration of functionally graded carbon nanotube reinforced composite cylindrical panels with general elastic supports

NASA Astrophysics Data System (ADS)

Xie, Fei; Tang, Jinyuan; Wang, Ailun; Shuai, Cijun; Wang, Qingshan

2018-05-01

In this paper, a unified solution for vibration analysis of the functionally graded carbon nanotube reinforced composite (FG-CNTRC) cylindrical panels with general elastic supports is carried out via using the Ritz method. The excellent accuracy and reliability of the present method are compared with the results of the classical boundary cases found in the literature. New results are given for vibration characteristics of FG-CNTRC cylindrical panels with various boundary conditions. The effects of the elastic restraint parameters, thickness, subtended angle and volume fraction of carbon nanotubes on the free vibration characteristic of the cylindrical panels are also reported.

Completion of evaluation of manufacturing processes for B/Al composites containing 0.2mm diameter boron fibers

NASA Technical Reports Server (NTRS)

Moore, T. J.; Moorhead, P. E.

1980-01-01

Four fabricators produced a total of 54 B/1100 Al, B/6061 Al, and B/2024 Al panels for evaluation. The 8 ply unidirectional, 45 to 50 volume percent, panels were made using 0.20 mm diameter boron fibers which were obtained from a single supplier. Hot press consolidation was carried out in vacuum except for one set of dry woven tape panels which were hot pressed in air. A single testing contractor conducted nondestructive inspection, metallography, fractography and mechanical property tests. The mechanical property tests included 21 and 260 C tensile tests and 21 C shear tests. Panel quality, as measured by nondestructive evaluation, was generally good as were the 21 C tensile properties. The panels hot pressed in air delaminated in the shear tests. Shear strength values were lower in these panels. But tensile strengths were not affected by the delaminations because of the relation between the tensile loading direction and the delaminations. Composite tensile strength was found to be proportional to the volume percent boron and the aluminum matrix rather than to the tape used or fabrication technique. Suitability of these composites for 260 C service was confirmed by tensile tests.

Processing Science of Epoxy Resin Composites

DTIC Science & Technology

1984-01-15

3 2.2 LAMINATE FABRICATION 30 2.2.1 Baseline Laminate Fabrication 30 2.2.2 Large Laminate Fabrication 36 2.3 DIFFUSIVITY AND SOLUBILITY...Thick Laminate 42 28 Baseline Cure Cycle With Specimen Advancement Levels 45 29 Composite Panel Fabrication 47 30 Composite Panel Fabrication 48 31...first change was the elimination of the different 1 resin formulations and concentration on the normal or baseline 5208/T300 prepreg as produced by

Aviation Simulators for the Desktop: Panel and Demonstrations

NASA Technical Reports Server (NTRS)

Pisanich, Greg; Rosekind, Marl R. (Technical Monitor)

1997-01-01

Panel Members are: Christine M. Mitchell (Georgia Tech), Michael T. Palmer (NASA Langley), Greg Pisani (NASA Ames), and Amy R. Pritchett (MIT). The Panel members are affiliated with aviation human factors groups from NASA Ames, NASA Langley, MITCHELL Department of Aerospace and Aeronautical Engineering, and Georgia Technics Center for Human-Machine Systems Research. Panelists will describe the simulator(s) used in their respective institutions including a description of the FMS aircraft models, software, hardware, and displays. Panelists will summarize previous, on-going, and planned empirical studies conducted with the simulators. Greg Pisanich will describe two NASA Ames simulation systems: the Stone Soup Simulator (SSS), and the Airspace Operations Human Factors Simulation Laboratory. The the Stone Soup Simulator is a desktop-based, research flight simulator that includes mode control, flight management, and datalink functionality. It has been developed as a non-proprietary simulator that can be easily distributed to academic and industry researchers who are collaborating on NASA research projects. It will be used and extended by research groups represented by at least two panelists (Mitchell and Palmer). The Airspace Operations Simulator supports the study of air traffic control in conjunction with the flight deck. This simulator will be used provide an environment in which many AATT and free flight concepts can be demonstrated and evaluated. Mike Palmer will describe two NASA Langley efforts: The Langley Simulator and MD-11 extensions to the NASA Amesbury simulator. The first simulator is publicly available and combines a B-737 model with a high fidelity flight management system. The second simulator enhances the S3 simulator with MD-11 electronic flight displays together with modifications to the flight and FMS models to emulate MD-11 dynamics and operations. Chris Mitchell will describe GT-EFIRT (Georgia Tech-Electronic Flight Instrument Research Tool) and B-757 enhancements to the NASA Ames S3. GT-EFIRT is a medium fidelity simulator used to conduct preliminary studies of the CATS (crew activity tracking system). Like the Langley efforts with S3, the Georgia Tech enhancements will allow it to emulate the dynamics and operations of a widely used glass cockpit. Amy Pritchett will describe the MIT simulator(s) that have been used in a range of research investigating cockpit displays, warning devices, and flight deck-ATC interaction.

Study of advanced composite structural design concepts for an arrow wing supersonic cruise configuration

NASA Technical Reports Server (NTRS)

Turner, M. J.; Grande, D. L.

1978-01-01

Based on estimated graphite and boron fiber properties, allowable stresses and strains were established for advanced composite materials. Stiffened panel and conventional sandwich panel concepts were designed and analyzed, using graphite/polyimide and boron/polyimide materials. The conventional sandwich panel was elected as the structural concept for the modified wing structure. Upper and lower surface panels of the arrow wing structure were then redesigned, using high strength graphite/polyimide sandwich panels, retaining the titanium spars and ribs from the prior study. The ATLAS integrated analysis and design system was used for stress analysis and automated resizing of surface panels. Flutter analysis of the hybrid structure showed a significant decrease in flutter speed relative to the titanium wing design. The flutter speed was increased to that of the titanium design by selective increase in laminate thickness and by using graphite fibers with properties intermediate between high strength and high modulus values.

POSTOP: Postbuckled open-stiffener optimum panels-theory and capability

NASA Technical Reports Server (NTRS)

Dickson, J. N.; Biggers, S. B.

1984-01-01

The computer program POSTOP was developed to serve as an aid in the analysis and sizing of stiffened composite panels that are loaded in the postbuckling regime. A comprehensive set of analysis routines was coupled to a widely used optimization program to produce this sizing code. POSTOP is intended for the preliminary design of metal or composite panels with open-section stiffeners, subjected to multiple combined biaxial compression (or tension), shear and normal pressure load cases. Longitudinal compression, however, is assumed to be the dominant loading. Temperature, initial bow eccentricity and load eccentricity effects are included. The panel geometry is assumed to be repetitive over several bays in the longitudinal (stiffener) direction as well as in the transverse direction. Analytical routines are included to compute panel stiffnesses, strains, local and panel buckling loads, and skin/stiffener interface stresses. The resulting program is applicable to stiffened panels as commonly used in fuselage, wing, or empennage structures. The analysis procedures and rationale for the assumptions used therein are described in detail.

Multiscale Fatigue Life Prediction for Composite Panels

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Yarrington, Phillip W.; Arnold, Steven M.

2012-01-01

Fatigue life prediction capabilities have been incorporated into the HyperSizer Composite Analysis and Structural Sizing Software. The fatigue damage model is introduced at the fiber/matrix constituent scale through HyperSizer s coupling with NASA s MAC/GMC micromechanics software. This enables prediction of the micro scale damage progression throughout stiffened and sandwich panels as a function of cycles leading ultimately to simulated panel failure. The fatigue model implementation uses a cycle jumping technique such that, rather than applying a specified number of additional cycles, a specified local damage increment is specified and the number of additional cycles to reach this damage increment is calculated. In this way, the effect of stress redistribution due to damage-induced stiffness change is captured, but the fatigue simulations remain computationally efficient. The model is compared to experimental fatigue life data for two composite facesheet/foam core sandwich panels, demonstrating very good agreement.

Post-Buckling and Ultimate Strength Analysis of Stiffened Composite Panel Base on Progressive Damage

NASA Astrophysics Data System (ADS)

Zhang, Guofan; Sun, Xiasheng; Sun, Zhonglei

Stiffened composite panel is the typical thin wall structure applied in aerospace industry, and its main failure mode is buckling subjected to compressive loading. In this paper, the development of an analysis approach using Finite Element Method on post-buckling behavior of stiffened composite structures under compression was presented. Then, the numerical results of stiffened panel are obtained by FE simulations. A thorough comparison were accomplished by comparing the load carrying capacity and key position strains of the specimen with test. The comparison indicates that the FEM results which adopted developed methodology could meet the demand of engineering application in predicting the post-buckling behavior of intact stiffened structures in aircraft design stage.

Design of hat-stiffened composite panels loaded in axial compression

NASA Astrophysics Data System (ADS)

Paul, T. K.; Sinha, P. K.

An integrated step-by-step analysis procedure for the design of axially compressed stiffened composite panels is outlined. The analysis makes use of the effective width concept. A computer code, BUSTCOP, is developed incorporating various aspects of buckling such as skin buckling, stiffener crippling and column buckling. Other salient features of the computer code include capabilities for generation of data based on micromechanics theories and hygrothermal analysis, and for prediction of strength failure. Parametric studies carried out on a hat-stiffened structural element indicate that, for all practical purposes, composite panels exhibit higher structural efficiency. Some hybrid laminates with outer layers made of aluminum alloy also show great promise for flight vehicle structural applications.

46 CFR 171.010 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... weather deck extending no more than one-half of the vessel's length over deck (LOD) measured over the weather deck. (b) Deepest subdivision load line means the waterline that corresponds to the deepest draft... tangent to the waterline. (g) Flush deck means a continuous weather deck located at the uppermost sheer...

46 CFR 171.010 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... weather deck extending no more than one-half of the vessel's length over deck (LOD) measured over the weather deck. (b) Deepest subdivision load line means the waterline that corresponds to the deepest draft... tangent to the waterline. (g) Flush deck means a continuous weather deck located at the uppermost sheer...

PV module mounting method and mounting assembly

DOEpatents

Lenox, Carl J.S.; Johnson, Kurt M.

2013-04-23

A method for mounting PV modules to a deck includes selecting PV module layout pattern so that adjacent PV module edges are spaced apart. PV mounting and support assemblies are secured to the deck according to the layout pattern using fasteners extending into the deck. The PV modules are placed on the PV mounting and support assemblies. Retaining elements are located over and secured against the upper peripheral edge surfaces of the PV modules so to secure them to the deck with the peripheral edges of the PV modules spaced apart from the deck. In some examples a PV module mounting assembly, for use on a shingled deck, comprises flashing, a base mountable on the flashing, a deck-penetrating fastener engageable with the base and securable to the deck so to secure the flashing and the base to the shingled deck, and PV module mounting hardware securable to the base.

Design, fabrication, installation and flight service evaluation of a composite cargo ramp skin on a model CH-53 helicopter

NASA Technical Reports Server (NTRS)

Lowry, D. W.; Rich, M. J.

1983-01-01

The installation of a composite skin panel on the cargo ramp of a CH-530 marine helicopter is discussed. The composite material is of Kevlar/Epoxy (K/E) which replaces aluminum outer skins on the aft two bays of the ramp. The cargo ramp aft region was selected as being a helicopter airframe surface subjected to possible significant field damage and would permit an evaluation of the long term durability of the composite skin panel. A structural analysis was performed and the skin shears determined. Single lap joints of K/E riveted to aluminum were statically tested. The joint tests were used to determine bearing allowables and the required K/E skin gage. The K/E skin panels riveted to aluminum edge members were tested in a shear fixture to confirm the allowable shear and bearing strengths. Impact tests were conducted on aluminum skin panels to determine energy level and damage relationship. The K/E skin panels of various ply orientations and laminate thicknesses were then impacted at similar energy levels. The results of the analysis and tests were used to determine the required K/E skin gages in each of the end two bays of the ramp.

Investigation of Composite Structures

NASA Technical Reports Server (NTRS)

Hyer, Michael W.

2000-01-01

This final report consists of a compilation of four separate written documents, three dealing with the response and failure of elliptical composite cylinders to an internal pressure load, and the fourth dealing with the influence of manufacturing imperfections in curved composite panels. The three focused on elliptical cylinders consist of the following: 1 - A paper entitled "Progressive Failure Analysis of Internally Pressurized Elliptical Composite Cylinders," 2 - A paper entitled "Influence of Geometric Nonlinearities on the Response and Failure of Internally Pressurized Elliptical Composite Cylinders," and 3 - A report entitled "Response and Failure of Internally Pressurized Elliptical Composite Cyclinders." The document which deals with the influence of manufacturing imperfections is a paper entitled "Manufacturing Distortions of Curved Composite Panels."

Babes in the Woods: The Wanderings of the National Reading Panel.

ERIC Educational Resources Information Center

Yatvin, Joanne

2002-01-01

Former member of the National Reading Panel criticizes the composition, deliberations, and decisions of the panel, authorized by Congress in 1997, leading to its April 2000 report supporting the hierarchy-of-skills reading model. (PKP)

Using Indigenous Materials for Construction

DTIC Science & Technology

2015-07-01

Theoretical models were devised for prediction of the structural attributes of indigenous ferrocement sheets and sandwich composite panels comprising the...indigenous ferrocement skins and aerated concrete core. Structural designs were developed for these indigenous sandwich composite panels in typical...indigenous materials and building systems developed in the project were evaluated. Numerical modeling capabilities were developed for structural

Detecting damage in full-scale honeycomb sandwich composite curved fuselage panels through frequency response

NASA Astrophysics Data System (ADS)

Leone, Frank A., Jr.; Ozevin, Didem; Mosinyi, Bao; Bakuckas, John G., Jr.; Awerbuch, Jonathan; Lau, Alan; Tan, Tein-Min

2008-03-01

Preliminary tests were conducted using frequency response (FR) characteristics to determine damage initiation and growth in a honeycomb sandwich graphite/epoxy curved panel. This investigation was part of a more general study investigating the damage tolerance characteristics of several such panels subjected to quasi-static internal pressurization combined with hoop and axial loading. The panels were tested at the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration William J. Hughes Technical Center in Atlantic City, NJ. The overall program objective was to investigate the damage tolerance characteristics of full-scale composite curved aircraft fuselage panels and the evolution of damage under quasi-static loading up to failure. This paper focuses on one aspect of this comprehensive investigation: the effect of state-of-damage on the characteristics of the frequency response of the subject material. The results presented herein show that recording the frequency response could be used for real-time monitoring of damage growth and in determining damage severity in full-scale composites fuselage aircraft structures.

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

Finishes for Wood Decks

Treesearch

Mark Knaebe

2013-01-01

Wood decks have become an important part of residential construction. Wood decks can add versatile living space to a home and, with minimal maintenance, provide decades of use. However, wood decks are exposed to high levels of stress from severe weather conditions that shrink and swell the wood. Without proper maintenance, wood decks can develop problems such as checks...

Properties of polyurethane foam/coconut coir fiber as a core material and as a sandwich composites component

NASA Astrophysics Data System (ADS)

Azmi, M. A.; Abdullah, H. Z.; Idris, M. I.

2013-12-01

This research focuses on the fabrication and characterization of sandwich composite panels using glass fiber composite skin and polyurethane foam reinforced coconut coir fiber core. The main objectives are to characterize the physical and mechanical properties and to elucidate the effect of coconut coir fibers in polyurethane foam cores and sandwich composite panels. Coconut coir fibers were used as reinforcement in polyurethane foams in which later were applied as the core in sandwich composites ranged from 5 wt% to 20 wt%. The physical and mechanical properties found to be significant at 5 wt% coconut coir fiber in polyurethane foam cores as well as in sandwich composites. It was found that composites properties serve better in sandwich composites construction.

Control of Thermal Deflection, Panel Flutter and Acoustic Fatigue at Elevated Temperatures Using Shape Memory Alloys

NASA Technical Reports Server (NTRS)

Mei, Chuh; Huang, Jen-Kuang

1996-01-01

The High Speed Civil Transport (HSCT) will have to be designed to withstand high aerodynamic load at supersonic speeds (panel flutter) and high acoustic load (acoustic or sonic fatigue) due to fluctuating boundary layer or jet engine acoustic pressure. The thermal deflection of the skin panels will also alter the vehicle's configuration, thus it may affect the aerodynamic characteristics of the vehicle and lead to poor performance. Shape memory alloys (SMA) have an unique ability to recover large strains completely when the alloy is heated above the characteristic transformation (austenite finish T(sub f)) temperature. The recovery stress and elastic modulus are both temperature dependent, and the recovery stress also depends on the initial strain. An innovative concept is to utilize the recovery stress by embedding the initially strained SMA wire in a graphite/epoxy composite laminated panel. The SMA wires are thus restrained and large inplane forces are induced in the panel at elevated temeperatures. By embedding SMA in composite panel, the panel becomes much stiffer at elevated temperatures. That is because the large tensile inplane forces induced in the panel from the SMA recovery stress. A stiffer panel would certainly yield smaller dynamic responses.

High temperature structural sandwich panels

NASA Astrophysics Data System (ADS)

Papakonstantinou, Christos G.

High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several hundred degrees Centigrade. Hence the material has excellent potential for various types of applications. The analytical predictions from both models provide reasonably accurate results. Glass, AR-glass, carbon and Nicalon tows and carbon fabrics could be successfully used as skin reinforcements increasing the flexural stiffness and strength of the core. No occurrence of fiber delamination was observed.

Weight optimal design of lateral wing upper covers made of composite materials

NASA Astrophysics Data System (ADS)

Barkanov, Evgeny; Eglītis, Edgars; Almeida, Filipe; Bowering, Mark C.; Watson, Glenn

2016-09-01

The present investigation is devoted to the development of a new optimal design of lateral wing upper covers made of advanced composite materials, with special emphasis on closer conformity of the developed finite element analysis and operational requirements for aircraft wing panels. In the first stage, 24 weight optimization problems based on linear buckling analysis were solved for the laminated composite panels with three types of stiffener, two stiffener pitches and four load levels, taking into account manufacturing, reparability and damage tolerance requirements. In the second stage, a composite panel with the best weight/design performance from the previous study was verified by nonlinear buckling analysis and optimization to investigate the effect of shear and fuel pressure on the performance of stiffened panels, and their behaviour under skin post-buckling. Three rib-bay laminated composite panels with T-, I- and HAT-stiffeners were modelled with ANSYS, NASTRAN and ABAQUS finite element codes to study their buckling behaviour as a function of skin and stiffener lay-ups, stiffener height, stiffener top and root width. Owing to the large dimension of numerical problems to be solved, an optimization methodology was developed employing the method of experimental design and response surface technique. Optimal results obtained in terms of cross-sectional areas were verified successfully using ANSYS and ABAQUS shared-node models and a NASTRAN rigid-linked model, and were used later to estimate the weight of the Advanced Low Cost Aircraft Structures (ALCAS) lateral wing upper cover.

Novel Composites for Wing and Fuselage Applications

NASA Technical Reports Server (NTRS)

Suarez, J. A.; Buttitta, C.

1996-01-01

Design development was successfully completed for textile preforms with continuous cross-stiffened epoxy panels with cut-outs. The preforms developed included 3-D angle interlock weaving of graphite structural fibers impregnated by resin film infiltration (RFI) and shown to be structurally suitable under conditions requiring minimum acquisition costs. Design guidelines/analysis methodology for such textile structures are given. The development was expanded to a fuselage side-panel component of a subsonic commercial airframe and found to be readily scalable. The successfully manufactured panel was delivered to NASA Langley for biaxial testing. This report covers the work performed under Task 3 -- Cross-Stiffened Subcomponent; Task 4 -- Design Guidelines/Analysis of Textile-Reinforced Composites; and Task 5 -- Integrally Woven Fuselage Panel.

The Study of Stability of Compression-loaded Multispan Composite Panel Upon Failure of elements Binding it to Panel Supports

NASA Technical Reports Server (NTRS)

Zamula, G. N.; Ierusalimsky, K. M.; Fomin, V. P.; Grishin, V. I.; Kalmykova, G. S.

1999-01-01

The present document is a final technical report under the NCC-1-233 research program (dated September 15, 1998; see Appendix 5) carried out within co-operation between United States'NASA Langley RC and Russia's Goskomoboronprom in aeronautics, and continues similar programs, NCCW-73, NCC-1-233 and NCCW 1-233 accomplished in 1996, 1997, and 1998, respectively. The report provides results of "The study of stability of compression-loaded multispan composite panels upon failure of elements binding it to panel supports"; these comply with requirements established at TsAGI on 24 March 1998 and at NASA on 15 September 1998.

Structural analysis and sizing of stiffened, metal matrix composite panels for hypersonic vehicles

NASA Technical Reports Server (NTRS)

Collier, Craig S.

1992-01-01

The present method for strength and stability analyses of stiffened, fiber-reinforced composite panels to be used in hypersonic vehicle structures is of great generality, and can be linked with planar finite-element analysis (FEA). Nonlinear temperature and load-dependent material data for each laminate are used to 'build-up' the stiffened panel's membrane, bending, and membrane-bending coupling stiffness terms, as well as thermal coefficients. The resulting, FEA-solved thermomechanical forces and moments are used to calculate strain at any location in the panel; this allows an effective ply-by-ply orthotropic strength analysis to be conducted, together with orthotropic instability checks for each laminated segment of the cross-section.

Advanced emergency openings for commercial aircraft

NASA Technical Reports Server (NTRS)

Bement, L. J.; Schimmel, M. L.

1985-01-01

Explosively actuated openings in composite panels are proposed to enhance passenger survivability within commercial aircraft by providing improvements in emergency openings, fuselage venting, and fuel dump. The concept is to embed a tiny, highly stable explosive cord in the periphery of a load-carrying composite panel; on initiation of the cord, the panel is fractured to create a well-defined opening. The panel would be installed in the sides of the fuselage for passenger egress, in the top of the fuselage for smoke venting, and in the bottoms of the fuel cells for fuel dump. Described are the concerns with the use of explosive systems, safety improvements, advantages, experimental results, and recommended approach to gain acceptance and develop this concept.

Development of Electrostatically Clean Solar Array Panels

NASA Technical Reports Server (NTRS)

Stern, Theodore G.

2000-01-01

Certain missions require Electrostatically Clean Solar Array (ECSA) panels to establish a favorable environment for the operation of sensitive scientific instruments. The objective of this program was to demonstrate the feasibility of an ECSA panel that minimizes panel surface potential below 100mV in LEO and GEO charged particle environments, prevents exposure of solar cell voltage and panel insulating surfaces to the ambient environment, and provides an equipotential, grounded structure surrounding the entire panel. An ECSA panel design was developed that uses a Front Side Aperture-Shield (FSA) that covers all inter-cell areas with a single graphite composite laminate, composite edge clips for connecting the FSA to the panel substrate, and built-in tabs that interconnect the FSA to conductive coated coverglasses using a conductive adhesive. Analysis indicated the ability of the design to meet the ECSA requirements. Qualification coupons and a 0.5m x 0.5m prototype panel were fabricated and tested for photovoltaic performance and electrical grounding before and after exposure to acoustic and thermal cycling environments. The results show the feasibility of achieving electrostatic cleanliness with a small penalty in mass, photovoltaic performance and cost, with a design is structurally robust and compatible with a wide range of current solar panel technologies.

Noise from Aft Deck Exhaust Nozzles: Differences in Experimental Embodiments

NASA Technical Reports Server (NTRS)

Bridges, James

2014-01-01

Two embodiments of a rectangular nozzle on an aft deck are compared. In one embodiment the lower lip of the nozzle was extended with the sidewalls becoming triangles. In a second embodiment a rectangular nozzle was fitted with a surface that fit flush to the lower lip and extended outward from the sides of the nozzle, approximating a semi-infinite plane. For the purpose of scale-model testing, making the aft deck an integral part of the nozzle is possible for relatively short deck lengths, but a separate plate model is more flexible, accounts for the expanse of deck to the sides of the nozzle, and allows the nozzle to stand off from the deck. Both embodiments were tested and acoustic far-field results were compared. In both embodiments the extended deck introduces a new noise source, but the amplitude of the new source was dependent upon the span (cross-stream dimension) of the aft deck. The noise increased with deck length (streamwise dimension), and in the case of the beveled nozzle it increased with increasing aspect ratio. In previous studies of slot jets in wings it was noted that the increased noise from the extended aft deck appears as a dipole at the aft deck trailing edge, an acoustic source type with different dependence on velocity than jet mixing noise. The extraneous noise produced by the aft deck in the present studies also shows this behavior both in directivity and in velocity scaling.

Buckling Design and Analysis of a Payload Fairing One-Sixth Cylindrical Arc-Segment Panel

NASA Technical Reports Server (NTRS)

Kosareo, Daniel N.; Oliver, Stanley T.; Bednarcyk, Brett A.

2013-01-01

Design and analysis results are reported for a panel that is a 16th arc-segment of a full 33-ft diameter cylindrical barrel section of a payload fairing structure. Six such panels could be used to construct the fairing barrel, and, as such, compression buckling testing of a 16th arc-segment panel would serve as a validation test of the buckling analyses used to design the fairing panels. In this report, linear and nonlinear buckling analyses have been performed using finite element software for 16th arc-segment panels composed of aluminum honeycomb core with graphiteepoxy composite facesheets and an alternative fiber reinforced foam (FRF) composite sandwich design. The cross sections of both concepts were sized to represent realistic Space Launch Systems (SLS) Payload Fairing panels. Based on shell-based linear buckling analyses, smaller, more manageable buckling test panel dimensions were determined such that the panel would still be expected to buckle with a circumferential (as opposed to column-like) mode with significant separation between the first and second buckling modes. More detailed nonlinear buckling analyses were then conducted for honeycomb panels of various sizes using both Abaqus and ANSYS finite element codes, and for the smaller size panel, a solid-based finite element analysis was conducted. Finally, for the smaller size FRF panel, nonlinear buckling analysis was performed wherein geometric imperfections measured from an actual manufactured FRF were included. It was found that the measured imperfection did not significantly affect the panel's predicted buckling response

The internal bond and shear strength of hardwood veneered particleboard composites

Treesearch

P. Chow; J.J. Janowiak; E.W. Price

1986-01-01

The effects of several accelerated aging tests and weather exposures on hardwood reconstituted structural composite panels were evaluated. The results indicated that the internal bond and shear by tension loading strength reductions of the panels were affected by the exposure test method. The ranking of the effects of various exposure tests on strength values in an...

Simulating Damage Due to a Lightning Strike Event: Effects of Temperature Dependent Properties on Interlaminar Damage

NASA Technical Reports Server (NTRS)

Ghezeljeh, Paria Naghipour; Pineda, Evan Jorge

2014-01-01

A multidirectional, carbon fiber-epoxy, composite panel is subjected to a simulated lightning strike, within a finite element method framework, and the effect of material properties on the failure (delamination) response is investigated through a detailed numerical study. The numerical model of the composite panel consists of individual homogenized plies with user-defined, cohesive interface elements between them. Lightning strikes are simulated as an assumed combination of excessive heat and high pressure loadings. It is observed that the initiation and propagation of lightning-induced delamination is a significant function of the temperature dependency of interfacial fracture toughness. This dependency must be defined properly in order to achieve reliable predictions of the present lightning-induced delamination in the composite panel.

Force Criterion Prediction of Damage for Carbon/Epoxy Composite Panels Impacted by High Velocity Ice

NASA Astrophysics Data System (ADS)

Rhymer, Jennifer D.

The use of advanced fiber-reinforced polymer matrix composites in load-bearing aircraft structures is increasing, as evident by the various composites-intensive transport aircraft presently under development. A major impact source of concern for these structures is hail ice, which affects design and skin-sizing (skin thickness determination) at various locations of the aircraft. Impacts onto composite structures often cause internal damage that is not visually detectable due to the high strength and resiliency of the composite material (unlike impacts onto metallic structures). This internal damage and its effect on the performance of the structure are of great concern to the aircraft industry. The prediction of damage in composite structures due to SHI impact has been accomplished via experimental work, explicit dynamic nonlinear finite element analysis (FEA) and the definition of design oriented relationships. Experiments established the critical threshold and corresponding analysis provided contact force results not readily measurable in high velocity SHI impact experiments. The design oriented relationships summarize the FEA results and experimental database into contact force estimation curves that can be easily applied for damage prediction. Failure thresholds were established for the experimental conditions (panel thickness ranging from 1.56 to 4.66 mm and ice diameters from 38.1 to 61.0 mm). Additionally, the observations made by high-speed video during the impact event, and ultrasonic C-scan post-impact, showed how the ice failed during impact and the overall shape and location of the panel damage. Through analysis, the critical force, the force level where damage occurs above but not below, of a SHI impact onto the panel was found to be dependent only on the target structure. However, the peak force generated during impact was dependent on both the projectile and target. Design-oriented curves were generated allowing the prediction of the allowable velocity for given SHI diameter impact onto a known panel in order to estimated damage. Finally, a scaling relationship was established to predict the peak force developed onto composite panels impacted by SHI. This is useful in reducing the amount of experimental investigations, or computationally expensive simulation work, that would otherwise need to be performed to obtain these results.

Processing and Characterization of Peti Composites Fabricated by High Temperature Vartm (Section)

NASA Technical Reports Server (NTRS)

Ghose, Sayata; Cano, Roberto J.; Watson, Kent A.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Smith, Joseph G., Jr.; Loos, Alfred C.; Heider, Dirk

2011-01-01

The use of composites as primary structures on aerospace vehicles has increased dramatically over the past decade, but so have the production costs associated with their fabrication. For certain composites, high temperature vacuum assisted resin transfer molding (HT-VARTM) can offer reduced fabrication costs compared to conventional autoclave techniques. The process has been successfully used with phenylethynyl terminated imide (PETI) resins developed by NASA Langley Research Center (LaRC). In the current study, three PETI resins have been used to make test specimens using HT-VARTM. Based on previous work at NASA LaRC, larger panels with a quasi-isotropic lay-up were fabricated. The resultant composite specimens exhibited void contents of 3% by volume depending on the type of carbon fabric preform used. Mechanical properties of the panels were determined at both room and elevated temperatures. Fabric permeability characterizations and limited process modeling efforts were carried out to determine infusion times and composite panel size limitations. In addition, new PETI based resins were synthesized specifically for HT-VARTM.

High temperature resin matrix composites for aerospace structures

NASA Technical Reports Server (NTRS)

Davis, J. G., Jr.

1980-01-01

Accomplishments and the outlook for graphite-polyimide composite structures are briefly outlined. Laminates, skin-stiffened and honeycomb sandwich panels, chopped fiber moldings, and structural components were fabricated with Celion/LARC-160 and Celion/PMR-15 composite materials. Interlaminar shear and flexure strength data obtained on as-fabricated specimens and specimens that were exposed for 125 hours at 589 K indicate that epoxy sized and polyimide sized Celion graphite fibers exhibit essentially the same behavior in a PMR-15 matrix composite. Analyses and tests of graphite-polyimide compression and shear panels indicate that utilization in moderately loaded applications offers the potential for achieving a 30 to 50 percent reduction in structural mass compared to conventional aluminum panels. Data on effects of moisture, temperature, thermal cycling, and shuttle fluids on mechanical properties indicate that both LARC-160 and PMR-15 are suitable matrix materials for a graphite-polyimide aft body flap. No technical road blocks to building a graphite-polyimide composite aft body flap are identified.

PANDA2: Program for Minimum Weight Design of Stiffened, Composite, Locally Buckled Panels

DTIC Science & Technology

1986-09-01

a flat panel or a panel that spans less than about 45 degrees of circumference. However, in PANDA2 complete cylindrical shells can be treated by the...compression and that corresponding to maximum in-plane shear. It is usually best to treat complete cylindrical shells in this way rather than try to set up a...to treat panels, not complete cylindrical shells. Therefore, it is best applied to panels. In PANDA2 the curved edges of a cylindrical panel lie in

46 CFR 171.135 - Weather deck drainage on a vessel of 100 gross tons or more.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Weather deck drainage on a vessel of 100 gross tons or...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.135 Weather deck drainage on a vessel of 100 gross tons or more. The weather deck must have...

46 CFR 171.135 - Weather deck drainage on a vessel of 100 gross tons or more.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Weather deck drainage on a vessel of 100 gross tons or...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.135 Weather deck drainage on a vessel of 100 gross tons or more. The weather deck must have...

46 CFR 171.135 - Weather deck drainage on a vessel of 100 gross tons or more.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Weather deck drainage on a vessel of 100 gross tons or...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.135 Weather deck drainage on a vessel of 100 gross tons or more. The weather deck must have...

46 CFR 171.135 - Weather deck drainage on a vessel of 100 gross tons or more.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Weather deck drainage on a vessel of 100 gross tons or...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.135 Weather deck drainage on a vessel of 100 gross tons or more. The weather deck must have...

46 CFR 171.135 - Weather deck drainage on a vessel of 100 gross tons or more.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Weather deck drainage on a vessel of 100 gross tons or...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.135 Weather deck drainage on a vessel of 100 gross tons or more. The weather deck must have...

My Brother’s Keeper National Lab Week

NASA Image and Video Library

2016-03-02

Students in the My Brother’s Keeper program line the railings of an observation deck overlooking the Granular Mechanics and Regolith Operations Lab at NASA’s Kennedy Space Center in Florida. The spaceport is one of six NASA centers that participated in My Brother’s Keeper National Lab Week. The event is a nationwide effort to bring youth from underrepresented communities into federal labs and centers for hands-on activities, tours and inspirational speakers. Sixty students from the nearby cities of Orlando and Sanford visited Kennedy, where they toured the Vehicle Assembly Building, the Space Station Processing Facility and the center’s innovative Swamp Works Labs. The students also had a chance to meet and ask questions of a panel of subject matter experts from across Kennedy.

Progressive Fracture of Fiber Composite Build-Up Structures

NASA Technical Reports Server (NTRS)

Gotsis, Pascal K.; Chamis, C. C.; Minnetyan, Levon

1997-01-01

Damage progression and fracture of built-up composite structures is evaluated by using computational simulation. The objective is to examine the behavior and response of a stiffened composite (0/ +/- 45/90)(sub s6) laminate panel by simulating the damage initiation, growth, accumulation, progression and propagation to structural collapse. An integrated computer code, CODSTRAN, was augmented for the simulation of the progressive damage and fracture of built-up composite structures under mechanical loading. Results show that damage initiation and progression have significant effect on the structural response. Influence of the type of loading is investigated on the damage initiation, propagation and final fracture of the build-up composite panel.

Progressive Fracture of Fiber Composite Build-Up Structures

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Gotsis, Pascal K.; Chamis, C. C.

1997-01-01

Damage progression and fracture of built-up composite structures is evaluated by using computational simulation. The objective is to examine the behavior and response of a stiffened composite (0 +/-45/90)(sub s6) laminate panel by simulating the damage initiation, growth, accumulation, progression and propagation to structural collapse. An integrated computer code CODSTRAN was augmented for the simulation of the progressive damage and fracture of built-up composite structures under mechanical loading. Results show that damage initiation and progression to have significant effect on the structural response. Influence of the type of loading is investigated on the damage initiation, propagation and final fracture of the build-up composite panel.

Structural Durability of Damaged Metallic Panel Repaired with Composite Patches

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Chamis, Christos C.

1997-01-01

Structural durability/damage tolerance characteristics of an aluminum tension specimen possessing a short crack and repaired by applying a fiber composite surface patch is investigated via computational simulation. The composite patch is made of graphite/epoxy plies with various layups. An integrated computer code that accounts for all possible failure modes is utilized for the simulation of combined fiber-composite/aluminum structural degradation under loading. Damage initiation, growth, accumulation, and propagation to structural fracture are included in the simulation. Results show the structural degradation stages due to tensile loading and illustrate the use of computational simulation for the investigation of a composite patch repaired cracked metallic panel.

Alternatives to steel grid decks - phase II.

DOT National Transportation Integrated Search

2012-09-01

The primary objective of this research project was to investigate alternatives to open grid steel decks for movable bridges. Three alternative deck systems, including aluminum deck, ultra-high performance concrete (UHPC)-high-strength steel (HSS) dec...

A mass reduction effort of the electric and hybrid vehicle. [composite door panels

NASA Technical Reports Server (NTRS)

Freeman, R. B.; Jahnle, H. A.

1980-01-01

Weight reduction, cost competitiveness, and elimination of the intrusion beam resulted from the redesign and fabrication using composite materials of the door outer panel and intrusion beam from a Chevrolet Impala. The basis of the redesign involved replacing these two steel parts with a single compression molding using the unique approach of simultaneously curing a sheet molding compound outside panel with a continuous glass fiber intrusion strap. A weight reduction of nearly 11 pounds per door was achieved. Additional weight savings are possible by taking advantage of the elimination of the intrusion beam to design thinner door structures. The parts consolidation approach allows the composite structure to be cost competitive with the original steel design for both the lower production car models and for the near to midterm production vehicles using current state of the art composite production techniques. The design, prototype fabrication, costing, material, properties and compression molding production requirements are discussed.

View of deck of pony truss approach span. Deck system ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of deck of pony truss approach span. Deck system has failed at northwest corner. Looking south. - Naval Supply Annex Stockton, Daggett Road Bridge, Daggett Road traversing Burns Cut Off, Stockton, San Joaquin County, CA

Experimental Results From Stitched Composite Multi-Bay Fuselage Panels Tested Under Uni-Axial Compression

NASA Technical Reports Server (NTRS)

Baker, Donald J.

2004-01-01

The experimental results from two stitched VARTM composite panels tested under uni-axial compression loading are presented. The curved panels are divided by frames and stringers into five or six bays with a column of three bays along the compressive loading direction. The frames are supported at the ends to resist out-of-plane translation. Back-to-back strain gages are used to record the strain and displacement transducers were used to record the out-of-plane displacements. In addition a full-field measurement technique that utilizes a camera-based-stero-vision system was used to record displacements. The panels were loaded in increments to determine the first bay to buckle. Loading was discontinued at limit load and the panels were removed from the test machine for impact testing. After impacting at 20 ft-lbs to 25 ft-lbs of energy with a spherical indenter, the panels were loaded in compression until failure. Impact testing reduced the axial stiffness 4 percent and less than 1 percent. Postbuckled axial panel stiffness was 52 percent and 70 percent of the pre-buckled stiffness.

Structural Performance of a Compressively Loaded Foam-Core Hat-Stiffened Textile Composite Panel

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Dexter, Benson H.

1996-01-01

A structurally efficient hat-stiffened panel concept that utilizes a structural foam as a stiffener core material has been designed and developed for aircraft primary structural applications. This stiffener concept is fabricated from textile composite material forms with a resin transfer molding process. This foam-filled hat-stiffener concept is structurally more efficient than most other prismatically stiffened panel configurations in a load range that is typical for both fuselage and wing structures. The panel design is based on woven/stitched and braided graphite-fiber textile preforms, an epoxy resin system, and Rohacell foam core. The structural response of this panel design was evaluated for its buckling and postbuckling behavior with and without low-speed impact damage. The results from single-stiffener and multi-stiffener specimen tests suggest that this structural concept responds to loading as anticipated and has excellent damage tolerance characteristics compared to a similar panel design made from preimpregnated graphite-epoxy tape material.

Behavior of Frame-Stiffened Composite Panels with Damage

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.

2013-01-01

NASA, the Air Force Research Laboratory and The Boeing Company have worked to develop new low-cost, light-weight composite structures for aircraft. A Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept has been developed which offers advantages over traditional metallic structures. In this concept, a stitched carbon-epoxy material system has been developed with the potential for reducing the weight and cost of transport aircraft structure by eliminating fasteners, thereby reducing part count and labor. Stitching and the use of thin skins with rod-stiffeners to move loading away from the morevulnerable outer surface produces a structurally efficient, damage tolerant design. This study focuses on the behavior of PRSEUS panels loaded in the frame direction and subjected to severe damage in the form of a severed central frame in a three-frame panel. Experimental results for a pristine two-frame panel and analytical predictions for pristine two-frame and three-frame panels as well as damaged three-frame panels are described.

Thermal and Mechanical Buckling and Postbuckling Responses of Selected Curved Composite Panels

NASA Technical Reports Server (NTRS)

Breivik, Nicole L.; Hyer, Michael W.; Starnes, James H., Jr.

1998-01-01

The results of an experimental and numerical study of the buckling and postbuckling responses of selected unstiffened curved composite panels subjected to mechanical end shortening and a uniform temperature increase are presented. The uniform temperature increase induces thermal stresses in the panel when the axial displacement is constrained. An apparatus for testing curved panels at elevated temperature is described, numerical results generated by using a geometrically nonlinear finite element analysis code are presented. Several analytical modeling refinements that provide more accurate representation of the actual experimental conditions, and the relative contribution of each refinement, are discussed. Experimental results and numerical predictions are presented and compared for three loading conditions including mechanical end shortening alone, heating the panels to 250 F followed by mechanical end shortening, and heating the panels to 400 F. Changes in the coefficients of thermal expansion were observed as temperature was increased above 330 F. The effects of these changes on the experimental results are discussed for temperatures up to 400 F.

Life-cycle assessment of redwood decking in the United States with a comparison to three other decking materials

Treesearch

R. Bergman; H. Sup-Han; E. Oneil; I. Eastin

2013-01-01

The goal of the study was to conduct a life-cycle inventory (LCI) of California redwood (Sequoia sempervirens) decking that would quantify the critical environmental impacts of decking from cradle to grave. Using that LCI data, a life-cycle assessment (LCA) was produced for redwood decking. The results were used to compare the environmental footprint...

40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Deck Seam Length Factors a (SD) for... (SD) for Internal Floating Roof Tanks Deck construction Typical deck seam length factor Continuous... decks only. Units for SD are feet per square feet. b SD=1/W, where W = sheet width (feet). c If no...

40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deck Seam Length Factors a (SD) for... (SD) for Internal Floating Roof Tanks Deck construction Typical deck seam length factor Continuous... decks only. Units for SD are feet per square feet. b SD=1/W, where W = sheet width (feet). c If no...

Composites from southern pine juvenile wood. Part 1. Panel fabrication and initial properties

Treesearch

Anton D. Pugel; Eddie W. Price; Chung-Yun Hse

1990-01-01

Flakeboard, particleboard, and fiberboard panels were manufactured from four different sources of southern pine (Pinus taeda L.) juvenile wood. The sources were: 1) fastgrown trees; 2) the inner core of older trees; 3) branches; and 4) tops. The juvenile wood particle sizes and panel densities were similar to those used for control panels made from...

22. FANTAIL DECK, SHOWING DETAIL OF DECK EXTENSION AND EXTERIOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. FANTAIL DECK, SHOWING DETAIL OF DECK EXTENSION AND EXTERIOR LOCKING MECHANISM ON HATCH DOOR TO CREW'S BERTHING. - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

SouthWest Elevation, Plan Showing Deck Framing, Deck Plan, Plan of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South-West Elevation, Plan Showing Deck Framing, Deck Plan, Plan of Collar Beams, Etc., Typical Framing Details, End Elevations, Elevation of Scarf Top Chord, Joint Details - Perrine's Bridge, Spanning Wallkill River, Rifton, Ulster County, NY

Hydraulic forces on submerged bridge decks.

DOT National Transportation Integrated Search

2008-09-01

Bridge decks can be subjected to large horizontal forces when overtopping occurs. These forces may result in the displacement of bridge decks from the bents. This paper reports on the results of a laboratory study of horizontal forces on bridge decks...

Damage detection and repair methods for GFRP bridge decks : [summary].

DOT National Transportation Integrated Search

2011-01-01

Glass fiber-reinforced polymer (GFRP) decks offer : advantages as replacements for worn steel bridge : decks because of their high strength-to-weight : ratio and fast installation time. However, before : GFRP decks can be put into service, methods : ...

Reflected Deck Plan and Deck Plan from Pre2004 Fire and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Reflected Deck Plan and Deck Plan from Pre-2004 Fire and Existing Condition, 2009 - Boston & Maine Railroad, Berlin Branch Bridge #148.81, Formerly spanning Moose Brook at former Boston & Maine Railroad, Gorham, Coos County, NH

Delamination measurement of a laminates composite panel due to hole punching based on the focus variation technique

NASA Astrophysics Data System (ADS)

Abdullah, A. B.; Zain, M. S. M.; Abdullah, M. S.; Samad, Z.

2017-07-01

Structural materials, such as composite panels, must be assembled, and such panels are typically constructed via the insertion of a fastener through a drilled hole. The main problem encountered in drilling is delamination, which affects assembly strength. The cost of drilling is also high because of the severe wear on drill bits. The main goal of this research is to develop a new punching method as an alternative to drilling during hole preparation. In this study, the main objective is to investigate the effect of different puncher profiles on the quality of holes punched into carbon fiber reinforcement polymer (CFRP) composite panels. Six types of puncher profiles were fabricated with minimum die clearance (1%), and two quality aspects, namely, incomplete shearing and delamination factor, were measured. The conical puncher incurred the least defects in terms of delamination and yielded an acceptable amount of incomplete shearing in comparison with the other punchers.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, materials costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structure. Key technologies, such as large crown panel fabrication, were pursued for low cost. An intricate bond panel design and manufacturing concept were selected based on the efforts of the Design Build Team. The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and use of low cost materials forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing costs by 18 pct. and weight by 45 pct. relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, material costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structures. Boeing's efforts under the NASA ACT program have pursued key technologies for low-cost, large crown panel fabrication. An intricate bond panel design and manufacturing concepts were selected based on the efforts of the Design Build Team (DBT). The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with the Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and utilization of low-cost material forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing cost by 18 percent and weight by 45 percent relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Studying impact damage on carbon-fiber reinforced aircraft composite panels with sonicir

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han Xiaoyan; Zhang Ding; He Qi

2011-06-23

Composites are becoming more important materials in commercial aircraft structures such as the fuselage and wings with the new B787 Dreamliner from Boeing which has the target to utilize 50% by weight of composite materials. Carbon-fiber reinforced composites are the material of choice in aircraft structures. This is due to their light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, by reducing the aircraft's body weight by using such lighter structures, the cost of fuel can be greatly reduced with the high jet fuel price for commercial airlines. However, these compositesmore » are prone to impact damage and the damage may occur without any observable sign on the surface, yet resulting in delaminations and disbonds that may occur well within the layers. We are studying the impact problem with carbon-fiber reinforced composite panels and developing SonicIR for this application as a fast and wide-area NDE technology. In this paper, we present our results in studying composite structures including carbon-fiber reinforced composite materials, and preliminary quantitative studies on delamination type defect depth identification in the panels.« less

Large Scale Composite Manufacturing for Heavy Lift Launch Vehicles

NASA Technical Reports Server (NTRS)

Stavana, Jacob; Cohen, Leslie J.; Houseal, Keth; Pelham, Larry; Lort, Richard; Zimmerman, Thomas; Sutter, James; Western, Mike; Harper, Robert; Stuart, Michael

2012-01-01

Risk reduction for the large scale composite manufacturing is an important goal to produce light weight components for heavy lift launch vehicles. NASA and an industry team successfully employed a building block approach using low-cost Automated Tape Layup (ATL) of autoclave and Out-of-Autoclave (OoA) prepregs. Several large, curved sandwich panels were fabricated at HITCO Carbon Composites. The aluminum honeycomb core sandwich panels are segments of a 1/16th arc from a 10 meter cylindrical barrel. Lessons learned highlight the manufacturing challenges required to produce light weight composite structures such as fairings for heavy lift launch vehicles.

Response of Composite Fuselage Sandwich Side Panels Subjected to Internal Pressure and Axial Tension

NASA Technical Reports Server (NTRS)

Rouse, Marshall; Ambur, Damodar R.; Dopker, Bernard; Shah, Bharat

1998-01-01

The results from an experimental and analytical study of two composite sandwich fuselage side panels for a transport aircraft are presented. Each panel has two window cutouts and three frames and utilizes a distinctly different structural concept. These panels have been evaluated with internal pressure loads that generate biaxial tension loading conditions. Design limit load and design ultimate load tests have been performed on both panels. One of the sandwich panels was tested with the middle frame removed to demonstrate the suitability of this two-frame design for supporting the prescribed biaxial loading conditions with twice the initial frame spacing of 20 inches. A damage tolerance study was conducted on the two-frame panel by cutting a notch in the panel that originates at the edge of a cutout and extends in the panel hoop direction through the window-belt area. This panel with a notch was tested in a combined-load condition to demonstrate the structural damage tolerance at the design limit load condition. Both the sandwich panel designs successfully satisfied all desired load requirements in the experimental part of the study, and experimental results from the two-frame panel with and without damage are fully explained by the analytical results. The results of this study suggest that there is potential for using sandwich structural concepts with greater than the usual 20-in. wide frame spacing to further reduce aircraft fuselage structural weight.

Demonstration and Validation of a Composite Grid Reinforcement System for Bridge Decks

DTIC Science & Technology

2016-09-01

Abstract The Department of Defense (DoD) maintains a large array of road net- works that include vehicular bridges. Moving people, materials, and equip...tion. The application of corrosion-resistant technology can extend the ser- vice life of bridges and reduce maintenance costs. This DoD Corrosion... maintenance and capital costs for steel reinforcement. Maintaining serviceable bridges is essential to providing access to the facilities on the

Evaluation of a Composite Sandwich Fuselage Side Panel with Damage and Subjected to Internal Pressure

NASA Technical Reports Server (NTRS)

Rouse, Marshall; Ambur, Damodar R.; Bodine, Jerry; Dopker, Bernhard

1997-01-01

The results from an experimental and analytical study of a composite sandwich fuselage side panel for a transport aircraft are presented. The panel has two window cutouts and three frames, and has been evaluated with internal pressure loads that generate biaxial tension loading conditions. Design limit load and design ultimate load tests have been performed on the graphite-epoxy sandwich panel with the middle frame removed to demonstrate the suitability of this two-frame design for supporting the prescribed biaxial loading conditions with twice the initial frame spacing of 20 inches. The two-frame panel was damaged by cutting a notch that originates at the edge of a cutout and extends in the panel hoop direction through the window-belt area. This panel with a notch was tested in a combined-load condition to demonstrate the structural damage tolerance at the design limit load condition. The two panel configurations successfully satisfied all design load requirements in the experimental part of the study, and the three-frame and two-frame panel responses are fully explained by the analysis results. The results of this study suggest that there is potential for using sandwich structural concepts with greater than the usual 20-in.-wide frame spacing to further reduce aircraft fuselage structural weight.

Analysis of Composite Panel-Stiffener Debonding Using a Shell/3D Modeling Technique

NASA Technical Reports Server (NTRS)

Krueger, Ronald; Minguet, Pierre J.

2006-01-01

Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodology on structural level. For this purpose a panel was selected that was reinforced with stringers. Shear loading cases the panel to buckle and the resulting out-of-plane deformations initiate skin/stringer separation at the location of an embedded defect. For finite element analysis, the panel and surrounding load fixture were modeled with shell element. A small section of the stringer foot and the panel in the vicinity of the embedded defect were modeled with a local 3D solid model. A failure index was calculated by correlating computed mixed-mode failure criterion of the graphite/epoxy material.

Optimal Design of Grid-Stiffened Panels and Shells With Variable Curvature

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Jaunky, Navin

2001-01-01

A design strategy for optimal design of composite grid-stiffened structures with variable curvature subjected to global and local buckling constraints is developed using a discrete optimizer. An improved smeared stiffener theory is used for the global buckling analysis. Local buckling of skin segments is assessed using a Rayleigh-Ritz method that accounts for material anisotropy and transverse shear flexibility. The local buckling of stiffener segments is also assessed. Design variables are the axial and transverse stiffener spacing, stiffener height and thickness, skin laminate, and stiffening configuration. Stiffening configuration is herein defined as a design variable that indicates the combination of axial, transverse and diagonal stiffeners in the stiffened panel. The design optimization process is adapted to identify the lightest-weight stiffening configuration and stiffener spacing for grid-stiffened composite panels given the overall panel dimensions. in-plane design loads, material properties. and boundary conditions of the grid-stiffened panel or shell.

Advanced composites structural concepts and materials technologies for primary aircraft structures. Structural response and failure analysis: ISPAN modules users manual

NASA Technical Reports Server (NTRS)

Hairr, John W.; Huang, Jui-Ten; Ingram, J. Edward; Shah, Bharat M.

1992-01-01

The ISPAN Program (Interactive Stiffened Panel Analysis) is an interactive design tool that is intended to provide a means of performing simple and self contained preliminary analysis of aircraft primary structures made of composite materials. The program combines a series of modules with the finite element code DIAL as its backbone. Four ISPAN Modules were developed and are documented. These include: (1) flat stiffened panel; (2) curved stiffened panel; (3) flat tubular panel; and (4) curved geodesic panel. Users are instructed to input geometric and material properties, load information and types of analysis (linear, bifurcation buckling, or post-buckling) interactively. The program utilizing this information will generate finite element mesh and perform analysis. The output in the form of summary tables of stress or margins of safety, contour plots of loads or stress, and deflected shape plots may be generalized and used to evaluate specific design.

Test and Analyses of a Composite Multi-Bay Fuselage Panel Under Uni-Axial Compression

NASA Technical Reports Server (NTRS)

Li, Jian; Baker, Donald J.

2004-01-01

A composite panel containing three stringers and two frames cut from a vacuum-assisted resin transfer molded (VaRTM) stitched fuselage article was tested under uni-axial compression loading. The stringers and frames divided the panel into six bays with two columns of three bays each along the compressive loading direction. The two frames were supported at the ends with pins to restrict the out-of-plane translation. The free edges of the panel were constrained by knife-edges. The panel was modeled with shell finite elements and analyzed with ABAQUS nonlinear solver. The nonlinear predictions were compared with the test results in out-of-plane displacements, back-to-back surface strains on stringer flanges and back-to-back surface strains at the centers of the skin-bays. The analysis predictions were in good agreement with the test data up to post-buckling.

Failure Analysis of Discrete Damaged Tailored Extension-Shear-Coupled Stiffened Composite Panels

NASA Technical Reports Server (NTRS)

Baker, Donald J.

2005-01-01

The results of an analytical and experimental investigation of the failure of composite is tiffener panels with extension-shear coupling are presented. This tailored concept, when used in the cover skins of a tiltrotor aircraft wing has the potential for increasing the aeroelastic stability margins and improving the aircraft productivity. The extension-shear coupling is achieved by using unbalanced 45 plies in the skin. The failure analysis of two tailored panel configurations that have the center stringer and adjacent skin severed is presented. Finite element analysis of the damaged panels was conducted using STAGS (STructural Analysis of General Shells) general purpose finite element program that includes a progressive failure capability for laminated composite structures that is based on point-stress analysis, traditional failure criteria, and ply discounting for material degradation. The progressive failure predicted the path of the failure and maximum load capability. There is less than 12 percent difference between the predicted failure load and experimental failure load. There is a good match of the panel stiffness and strength between the progressive failure analysis and the experimental results. The results indicate that the tailored concept would be feasible to use in the wing skin of a tiltrotor aircraft.

Construction of bridge decks with precast prestressed deck planks

DOT National Transportation Integrated Search

2002-04-01

The purpose of this paper is to discuss the construction and early performance of two 1999 - 2000 bridge deck replacement state contracts in Illinois that included precast, prestressed concrete (PPC) deck planks. Metal stay-in-place forms used in one...

Empirical deck for phased construction and widening [summary].

DOT National Transportation Integrated Search

2017-06-01

The most common method used to design and analyze bridge decks, termed the traditional : method, treats a deck slab as if it were made of strips supported by inflexible girders. An : alternative the empirical method treats the deck slab as a ...

4. View of bridge deck from northeast approach (bridge deck ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. View of bridge deck from northeast approach (bridge deck from southwest approach is virtually identical - Big Cottonwood River Bridge No. 246, Spanning Big Cottonwood River at Cottonwood Street (City Road No. 165), New Ulm, Brown County, MN

Measurement of Dynamic Viscoelasticity of Full-Size Wood Composite Panels Using a Vibration Testing Method

Treesearch

Cheng Guan; Houjiang Zhang; John F. Hunt; Lujing Zhou; Dan Feng

2016-01-01

The dynamic viscoelasticity of full-size wood composite panels (WCPs) under the free-free vibrational state were determined by a vibration testing method. Vibration detection tests were performed on 194 pieces of three types of full-size WCPs (particleboard, medium density fiberboard, and plywood (PW)). The dynamic viscoelasticity from smaller specimens cut from the...

Potential of chicken feather fibre in wood MDF composites

Treesearch

Jerold E. Winandy; James H. Muehl; Jessie A. Micales; Ashok Raina; Walter Schmidt

2003-01-01

We made a series of aspen fibre medium density fibreboard panels adding various levels of chicken feather fibre to determine the relative effect of the feather fibre-wood fibre mixtures on composite panel properties. Chicken feathers are a waste product left over after processing chickens for meat. The feather fibre amounts used ranged from 20% to 95% and a 5%...

Chicken feather fiber as an additive in MDF composites

Treesearch

Jerrold E. Winandy; James H. Muehl; Jessie A. Glaeser; Walter Schmidt

2007-01-01

Medium density fiberboard (MDF) panels were made with aspen fiber and 0-95% chicken feather fiber (CFF) in 2.5%, 5%, or 25% increments, using 5% phenol formaldehyde resin as the adhesive. Panels were tested for mechanical and physical properties as well as decay. The addition of CFF decreased strength and stiffness of MDF-CFF composites compared with that of all-wood...

Effectiveness of exterior beam rotation prevention systems for bridge deck construction.

DOT National Transportation Integrated Search

2016-06-01

Bridge decks often overhang past the exterior girders in order to increase the width of the deck while limiting the required : number of longitudinal girders. The overhanging portion of the deck results in unbalanced eccentric loads to the exterior g...

21. FANTAIL DECK, SHOWING DETAIL OF DECK EXTENSION AND EXTERIOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. FANTAIL DECK, SHOWING DETAIL OF DECK EXTENSION AND EXTERIOR LOCKING MECHANISM ON HATCH DOOR TO CREW'S BERTHING. - U.S. Coast Guard Cutter WHITE LUPINE, U.S. Coast Guard Station Rockland, east end of Tillson Avenue, Rockland, Knox County, ME

Fabrication and evaluation of brazed titanium-clad borsic/aluminum skin-stringer panels

NASA Technical Reports Server (NTRS)

Bales, T. T.; Royster, D. M.; Mcwithey, R. R.

1980-01-01

A successful brazing process was developed and evaluated for fabricating full-scale titanium-clad Borsic/aluminum skin-stringer panels. A panel design was developed consisting of a hybrid composite skin reinforced with capped honeycomb-core stringers. Six panels were fabricated for inclusion in the program which included laboratory testing of panels at ambient temperatures and 533 K (500 F) and flight service evaluation on the NASA Mach 3 YF-12 airplane. All panels tested met or exceeded stringent design requirements and no deleterious effects on panel properties were detected followng flight service evaluation on the YF-12 airplane.

Self-diagnosis of damage in fibrous composites using electrical resistance measurements

NASA Astrophysics Data System (ADS)

Kang, Ji Ho; Paty, Spandana; Kim, Ran Y.; Tandon, G. P.

2006-03-01

The objective of this research was to develop a practical integrated approach using extracted features from electrical resistance measurements and coupled electromechanical models of damage, for in situ damage detection and sensing in carbon fiber reinforced plastic (CFRP) composite structures. To achieve this objective, we introduced specific known damage (in terms of type, size, and location) into CFRP laminates and established quantitative relationships with the electrical resistance measurements. For processing of numerous measurement data, an autonomous data acquisition system was devised. We also established a specimen preparation procedure and a method for electrode setup. Coupon and panel CFRP laminate specimens with several known damage were tested and post-processed with the measurement data. Coupon specimens with various sizes of artificial delaminations obtained by inserting Teflon film were manufactured and the resistance was measured. The measurement results showed that increase of delamination size led to increase of resistance implying that it is possible to sense the existence and size of delamination. Encouraged by the results of coupon specimens, we implemented the measurement system on panel specimens. Three different quasi-isotropic panels were designed and manufactured: a panel with artificial delamination by inserting Teflon film at the midplane, a panel with artificial delamination by inserting Teflon film between the second and third plies from the surface, and an undamaged panel. The first two panels were designed to determine the feasibility of detecting delamination using the developed measurement system. The third panel had no damage at first, and then three different sizes of holes were drilled at a chosen location. Panels were prepared using the established procedures with six electrode connections on each side making a total of twenty-four electrode connections for a panel. All possible pairs of electrodes were scanned and the resistance was measured for each pair. The measurement results showed the possibility of the established measurement system for an in-situ damage detection method for CFRP composite structures.

Impact-damaged graphite-thermoplastic trapezoidal-corrugation sandwich and semi-sandwich panels

NASA Technical Reports Server (NTRS)

Jegley, D.

1993-01-01

The results of a study of the effects of impact damage on compression-loaded trapezoidal-corrugation sandwich and semi-sandwich graphite-thermoplastic panels are presented. Sandwich panels with two identical face sheets and a trapezoidal corrugated core between them, and semi-sandwich panels with a corrugation attached to a single skin are considered in this study. Panels were designed, fabricated and tested. The panels were made using the manufacturing process of thermoforming, a less-commonly used technique for fabricating composite parts. Experimental results for unimpacted control panels and panels subjected to impact damage prior to loading are presented. Little work can be found in the literature about these configurations of thermoformed panels.

46 CFR 171.119 - Openings below the weather deck in the side of a vessel less than 100 gross tons.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Openings below the weather deck in the side of a vessel... Side of a Vessel Below the Bulkhead or Weather Deck § 171.119 Openings below the weather deck in the... waters, an opening port light is not permitted below the weather deck unless— (1) The sill is at least 30...

46 CFR 171.119 - Openings below the weather deck in the side of a vessel less than 100 gross tons.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Openings below the weather deck in the side of a vessel... Side of a Vessel Below the Bulkhead or Weather Deck § 171.119 Openings below the weather deck in the... waters, an opening port light is not permitted below the weather deck unless— (1) The sill is at least 30...

46 CFR 171.119 - Openings below the weather deck in the side of a vessel less than 100 gross tons.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Openings below the weather deck in the side of a vessel... Side of a Vessel Below the Bulkhead or Weather Deck § 171.119 Openings below the weather deck in the... waters, an opening port light is not permitted below the weather deck unless— (1) The sill is at least 30...

46 CFR 171.119 - Openings below the weather deck in the side of a vessel less than 100 gross tons.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Openings below the weather deck in the side of a vessel... Side of a Vessel Below the Bulkhead or Weather Deck § 171.119 Openings below the weather deck in the... waters, an opening port light is not permitted below the weather deck unless— (1) The sill is at least 30...

46 CFR 171.119 - Openings below the weather deck in the side of a vessel less than 100 gross tons.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Openings below the weather deck in the side of a vessel... Side of a Vessel Below the Bulkhead or Weather Deck § 171.119 Openings below the weather deck in the... waters, an opening port light is not permitted below the weather deck unless— (1) The sill is at least 30...

The development of an Infrared Environmental System for TOPEX Solar Panel Testing

NASA Technical Reports Server (NTRS)

Noller, E.

1994-01-01

Environmental testing and flight qualification of the TOPEX/POSEIDON spacecraft solar panels were performed with infrared (IR) lamps and a control system that were newly designed and integrated. The basic goal was more rigorous testing of the costly panels' new composite-structure design without jeopardizing their safety. The technique greatly reduces the costs and high risks of testing flight solar panels.

Review of Relocation of the System Program Office and Logistics Support for the F-117A Stealth Fighter

DTIC Science & Technology

1998-04-10

LMSW. Cost of Repair Number Avoided Nomenclature New Part Cost Repaired Cost Wing platypus panel $60,100 $4,500 10 $ 556,000 Lower rear door panel...72,200 7,000 48 3,129,600 Rear door trailing 76,000 6,000 2 140,000 edge panel Inboard platypus panel 56,000 4,200 46 2,410,400 Outboard platypus panel...Composites Shop’s contribution to resolving the problem consisted of the redesign of the wing and inboard and outboard platypus panels. The Advanced

Thermal-mechanical behavior of high precision composite mirrors

NASA Technical Reports Server (NTRS)

Kuo, C. P.; Lou, M. C.; Rapp, D.

1993-01-01

Composite mirror panels were designed, constructed, analyzed, and tested in the framework of a NASA precision segmented reflector task. The deformations of the reflector surface during the exposure to space enviroments were predicted using a finite element model. The composite mirror panels have graphite-epoxy or graphite-cyanate facesheets, separated by an aluminum or a composite honeycomb core. It is pointed out that in order to carry out detailed modeling of composite mirrors with high accuracy, it is necessary to have temperature dependent properties of the materials involved and the type and magnitude of manufacturing errors and material nonuniformities. The structural modeling and analysis efforts addressed the impact of key design and materials parameters on the performance of mirrors.

Progressive Fracture of Fiber Composite Builtup Structures

NASA Technical Reports Server (NTRS)

Gotsis, Pascal K.; Chamis, Christos C.; Minnetyan, Levon

1996-01-01

The damage progression and fracture of builtup composite structures was evaluated by using computational simulation to examine the behavior and response of a stiffened composite (0 +/- 45/90)(sub s6) laminate panel subjected to a bending load. The damage initiation, growth, accumulation, progression, and propagation to structural collapse were simulated. An integrated computer code (CODSTRAN) was augmented for the simulation of the progressive damage and fracture of builtup composite structures under mechanical loading. Results showed that damage initiation and progression have a significant effect on the structural response. Also investigated was the influence of different types of bending load on the damage initiation, propagation, and final fracture of the builtup composite panel.

MoMLA: From Panel to Gallery

ERIC Educational Resources Information Center

Vitanza, Victor, Ed.; Kuhn, Virginia, Ed.

2013-01-01

The work presented here in this "Panel to Gallery" was originally produced and assembled for the 2012 Modern Language Association Conference in Seattle, Washington. Similar to "From Gallery to Webtext", the event Victor curated for the 2006 College Composition and Communication Conference, this "Panel to Gallery" event at MLA set aside the…

Use of innovative concrete mixes for improved constructability and sustainability of bridge decks.

DOT National Transportation Integrated Search

2013-11-01

Bridge deck crack surveys were performed on twelve bridges on US-59 south of Lawrence, Kansas, to determine the effects of : mixture proportions, concrete properties, deck type, and girder type on the crack density of reinforced concrete bridge decks...

NYSDOT Bridge Deck Task Force evaluation of bridge deck cracking on NYSDOT bridges

DOT National Transportation Integrated Search

2007-02-01

This paper presents a summary of knowledge gained by the NYSDOT Bridge Deck Task Force (BDTF). Although the paper contains recommendations to reduce the prevalence and severity of bridge deck cracking, it does not include a silver bullet soluti...

Future Flight Decks

NASA Technical Reports Server (NTRS)

Arbuckle, P. Douglas; Abbott, Kathy H.; Abbott, Terence S.; Schutte, Paul C.

1998-01-01

The evolution of commercial transport flight deck configurations over the past 20-30 years and expected future developments are described. Key factors in the aviation environment are identified that the authors expect will significantly affect flight deck designers. One of these is the requirement for commercial aviation accident rate reduction, which is probably required if global commercial aviation is to grow as projected. Other factors include the growing incrementalism in flight deck implementation, definition of future airspace operations, and expectations of a future pilot corps that will have grown up with computers. Future flight deck developments are extrapolated from observable factors in the aviation environment, recent research results in the area of pilot-centered flight deck systems, and by considering expected advances in technology that are being driven by other than aviation requirements. The authors hypothesize that revolutionary flight deck configuration changes will be possible with development of human-centered flight deck design methodologies that take full advantage of commercial and/or entertainment-driven technologies.

ACEE composite structures technology

NASA Technical Reports Server (NTRS)

Quinlivan, John T.; Wilson, Robert D.; Smith, Peter J.; Johnson, Ronald W.

1984-01-01

Toppics addressed include: advanced composites on Boeing commercial aircraft; composite wing durability; damage tolerance technology development; heavily loaded wing panel design; and pressure containment and damage tolerance in fuselages.

Preliminary design of two Space Shuttle fluid physics experiments

NASA Technical Reports Server (NTRS)

Gat, N.; Kropp, J. L.

1984-01-01

The mid-deck lockers of the STS and the requirements for operating an experiment in this region are described. The design of the surface tension induced convection and the free surface phenomenon experiments use a two locker volume with an experiment unique structure as a housing. A manual mode is developed for the Surface Tension Induced Convection experiment. The fluid is maintained in an accumulator pre-flight. To begin the experiment, a pressurized gas drives the fluid into the experiment container. The fluid is an inert silicone oil and the container material is selected to be comparable. A wound wire heater, located axisymmetrically above the fluid can deliver three wattages to a spot on the fluid surface. These wattages vary from 1-15 watts. Fluid flow is observed through the motion of particles in the fluid. A 5 mw He/Ne laser illuminates the container. Scattered light is recorded by a 35mm camera. The free surface phenomena experiment consists of a trapezoidal cell which is filled from the bottom. The fluid is photographed at high speed using a 35mm camera which incorporated the entire cell length in the field of view. The assembly can incorporate four cells in one flight. For each experiment, an electronics block diagram is provided. A control panel concept is given for the surface induced convection. Both experiments are within the mid-deck locker weight and c-g limits.

Acoustically Tailored Composite Rotorcraft Fuselage Panels

NASA Technical Reports Server (NTRS)

Hambric, Stephen; Shepherd, Micah; Koudela, Kevin; Wess, Denis; Snider, Royce; May, Carl; Kendrick, Phil; Lee, Edward; Cai, Liang-Wu

2015-01-01

A rotorcraft roof sandwich panel has been redesigned to optimize sound power transmission loss (TL) and minimize structure-borne sound for frequencies between 1 and 4 kHz where gear meshing noise from the transmission has the most impact on speech intelligibility. The roof section, framed by a grid of ribs, was originally constructed of a single honeycomb core/composite face sheet panel. The original panel has coincidence frequencies near 700 Hz, leading to poor TL across the frequency range of 1 to 4 kHz. To quiet the panel, the cross section was split into two thinner sandwich subpanels separated by an air gap. The air gap was sized to target the fundamental mass-spring-mass resonance of the double panel system to less than 500 Hz. The panels were designed to withstand structural loading from normal rotorcraft operation, as well as 'man-on-the-roof' static loads experienced during maintenance operations. Thin layers of VHB 9469 viscoelastomer from 3M were also included in the face sheet ply layups, increasing panel damping loss factors from about 0.01 to 0.05. Measurements in the NASA SALT facility show the optimized panel provides 6-11 dB of acoustic transmission loss improvement, and 6-15 dB of structure-borne sound reduction at critical rotorcraft transmission tonal frequencies. Analytic panel TL theory simulates the measured performance quite well. Detailed finite element/boundary element modeling of the baseline panel simulates TL slightly more accurately, and also simulates structure-borne sound well.

Cognitive representations of flight-deck information attributes

NASA Technical Reports Server (NTRS)

Ricks, Wendell R.; Jonsson, Jon E.; Rogers, William H.

1994-01-01

A large number of aviation issues are generically being called fligh-deck information management issues, underscoring the need for an organization or classification structure. One objective of this study was to empirically determine how pilots organize flight-deck information attributes and -- based upon that data -- develop a useful taxonomy (in terms of better understanding the problems and directing solutions) for classifying flight-deck information management issues. This study also empirically determined how pilots model the importance of flight-deck information attributes for managing information. The results of this analysis suggest areas in which flight-deck researchers and designers may wish to consider focusing their efforts.

46 CFR 111.30-11 - Deck coverings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Deck coverings. 111.30-11 Section 111.30-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-11 Deck coverings. Non-conducting deck coverings, such as non-conducting...

46 CFR 111.30-11 - Deck coverings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Deck coverings. 111.30-11 Section 111.30-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-11 Deck coverings. Non-conducting deck coverings, such as non-conducting...

46 CFR 111.30-11 - Deck coverings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Deck coverings. 111.30-11 Section 111.30-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-11 Deck coverings. Non-conducting deck coverings, such as non-conducting...

46 CFR 111.30-11 - Deck coverings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Deck coverings. 111.30-11 Section 111.30-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-11 Deck coverings. Non-conducting deck coverings, such as non-conducting...

46 CFR 111.30-11 - Deck coverings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Deck coverings. 111.30-11 Section 111.30-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-11 Deck coverings. Non-conducting deck coverings, such as non-conducting...

46 CFR 132.320 - Helicopter-landing decks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck must...

46 CFR 132.320 - Helicopter-landing decks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck must...

46 CFR 132.320 - Helicopter-landing decks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck must...

46 CFR 132.320 - Helicopter-landing decks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck must...

46 CFR 132.320 - Helicopter-landing decks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck must...

Use of innovative concrete mixes for improved constructability and sustainability of bridge decks : [technical summary].

DOT National Transportation Integrated Search

2013-11-01

Bridge deck crack surveys were performed on twelve bridges on US-59 south of Lawrence, Kansas, to determine the effects of mixture proportions, concrete properties, deck type, and girder type on the crack density of reinforced concrete bridge decks.

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

Effects of simulated lightning on composite and metallic joints

NASA Technical Reports Server (NTRS)

Howell, W. E.; Plumer, J. A.

1982-01-01

The effects of simulated lightning strikes and currents on aircraft bonded joints and access/inspection panels were investigated. Both metallic and composite specimens were tested. Tests on metal fuel feed through elbows in graphite/epoxy structures were evaluated. Sparking threshold and residual strength of single lap bonded joints and sparking threshold of access/inspection panels and metal fuel feed through elbows are reported.

Bending analyses for 3D engineered structural panels made from laminated paper and carbon fabric

Treesearch

Jinghao Li; John F. Hunt; Zhiyong Cai; Xianyan Zhou

2013-01-01

This paper presents analysis of a 3-dimensional engineered structural panel (3DESP) having a tri-axial core structure made from phenolic impregnated laminated-paper composites with and without high strength composite carbon-fiber fabric laminated to the outside of both faces. Both I-beam equations and finite element method were used to analyze four-point bending of the...

Cantilever Beam Static and Dynamic Response Comparison with Mid-Point Bending for Thin MDF composite Panels

Treesearch

John F. Hunt; Houjiang Zhang; Zhiren Guo; Feng Fu

2013-01-01

A new cantilever beam apparatus has been developed to measure static and vibrational properties of small and thin samples of wood or composite panels. The apparatus applies a known displacement to a cantilever beam, measures its static load, then releases it into its natural first mode of transverse vibration. Free vibrational tip displacements as a function of time...