... Multibody Systems with Variable Kinematic Structure. ... DYNAMICS, INTERFACES, COMPATIBILITY, VARIABLES, CONFIGURATIONS, AXES ...

This paper presents a variational formulation of constrained dynamics of flexible multibody systems,

... VSpatial Kinematics,' Dynamic Analysis,' Deformable Multibody Systems,' Interval Analysis Scheme, Nonlinear Algebraic Equations, . ...

This paper uses spatial operator techniques to develop a new algorithm for the dynamics of multibody

This is a user's manual for a multibody dynamics computer program UCIN-DYNOCOMBS. The program is designed to study the Dynamics of Constrained Multibody systems. A multibody system is a collection of at least two linked or disjoint rigid bodies. In the pr...

An explicit-implicit staggered time-integration procedure is presented for the solution of multibody

A model of the nonlinear dynamics of a deformable maneuvering multibody system is described, whereby

... A parametric study of the design parameters which ... Descriptors : *SCALE MODELS, *DYNAMIC RESPONSE, *HELICOPTERS, MATHEMATICAL ...

... Various system theory concepts and research topics which ... applicability to this class of systems are identified ... The subject of multi-body dynamics is ...

Supercomputer optimizations for a computational method of solving stochastic, multibody, dynamic programming problems are presented. The computational method is valid for a general class of optimal control problems that are nonlinear, multibody dynamical ...

... Abstract : The dynamic equations of multi-body systems in the ... in the context of a single rigid body and then applied to a system of rigid bodies in an ...

Jan 22, 2011 ... Title: A Spatial Operator Algebra for Computational Multibody Dynamics. Authors: Jain, Abhinandan Rodriguez, Guillermo ...

is a rigid ball bouncing on a flat, rigid surface with a restitution coefficient strictly between 0 and 1 can be accommodated by turning the restitution coefficient to 0 if the normal velocity is below.10) Here e(j) is the restitution coefficient at noninterpenetration constraint (j). For ease of notation

Multibody dynamic musculoskeletal models capable of predicting muscle forces and joint contact pressures simultaneously would be valuable for studying clinical issues related to knee joint degeneration and restoration. Current three-dimensional multi-body knee models are either quasi-static with deformable contact or ...

... Accession Number : ADA532821. Title : Robust Stability and Control of Multi-Body Ground Vehicles with Uncertain Dynamics and Failures. ...

... 4. TITLE AND SUBTITLE Experimental Validation of a Coupled Fluid-Multibody Dynamics Model for Tanker Trucks 5a. CONTRACT NUMBER 5b. ...

Page 1. 2008-01-0777 Experimental Validation of a Coupled Fluid-Multibody Dynamics Model for Tanker Trucks Tamer ...

... Title : Experimental Validation of a Coupled Fluid-Multibody Dynamics Model for Tanker Trucks. Descriptive Note : Briefing charts. ...

... Title : Experimental Validation of a Coupled Fluid-Multibody Dynamics Model for Tanker Trucks. Descriptive Note : Conference paper. ...

mulation for a 3-dimensional (3-D) brick finite element method (FEM) based multibody dynamics analysis for helicopter rotors. Such a formulation requires an ...

The multibody dynamics of the Space Station is studied as affected by the suntracking motions of the

A general version of Lagrange's equations, including auxiliary nonholonomic, rheonomic conditions of

Ahmed A. Shabana SIMULATION OF MULTIBODY RAILROAD VEHICLE/TRACK DYNAMICS 1 DSL Dynamic Simulation Laboratory UIC University of Illinois at Chicago FINITE ELEMENT/ MULTIBODY SYSTEM ALGORITHMS FOR RAILROAD of Illinois at Chicago #12;Ahmed A. Shabana SIMULATION OF MULTIBODY RAILROAD VEHICLE/TRACK ...

Many complex systems can be modeled as a collection of interacting bodies, where the relative motion

Dynamics of multibody systems is of importance in the fields of robotics, biomechanics, spacecraft control, road and rail vehicle design, and dynamics of machinery. Many research problems have been solved and a considerable number of computer codes based on multibody formalisms is now available. This book reports ...

An efficient formulation is presented for a sub-class of multi-body dynamics problems that involve a

Apr 16, 2010 ... A. Jain, "Computational Robot Dynamics Using Spatial Operators", ... A. Jain, " Sensitivity Analysis of Multibody Dynamics", ...

Due to their structural flexibility, spacecraft and space manipulators are multibody systems with complex dynamics and possess a large number of degrees of freedom. Here the spatial operator algebra methodology is used to develop a new dynamics formulatio...

This paper outlines a methodology for determining the statistics associated with the time evolution of a nonlinear multi-body dynamic system operated under input uncertainty. The focus is on the dynamics of ground vehicle systems in environments character...

Recent developments in vehicle dynamics are discussed. Vehicle suspension systems, applications of multi-body dynamics problems in vehicle dynamics, rear steer, and special aspects of commercial vehicle dynamics are discussed.

The Final Report on reduced gravity multibody dynamics testing is presented. Tests were conducted on board the NASA KC-135 RGA in Houston, Texas. The objective was to analyze the effects of large angle rotations on flexible, multi-segmented structures. Th...

A variational-vector calculus approach is employed to derive a recursive formulation for dynamic analysis of flexible multibody systems. Kinematic relationships for adjacent flexible bodies are derived in a companion paper, using a state vector notation t...

This study extends to flexible multibody manipulators the recent results of the author on the use of

... modeling and analysis of transmissions. ... and other lightweight transmission applications, the ... of most helicopter transmissions and automobile rear ...

... The recursive kinematic equations and the joint reaction relationships are combined with the generalized Newton-Euler equations in order to obtain ...

... The integration of a multibody system dynamics program IMP with the control system design program MATRIXx is demonstrated. ...

A computerized procedure is presented for calculating instantaneous velocity changes due to discrete

... FUNCTIONS, *DUAL MODE, *THEOREMS, STABILITY, DYNAMICS, MANEUVERS, EQUATIONS, ANALOG SYSTEMS, BODIES, INVARIANCE ...

... Title : A Framework for Uncertainty Quantification in Nonlinear Multi-Body System Dynamics. Descriptive Note : Conference paper. ...

The equations of motion of a multibody system are nonlinear in nature, and thus pose a difficult problem in linear control design. One approach is to have a first-order approximation through the numerical perturbations at a given configuration, and to des...

In this reprint the kinematic and dynamic equations that govern the intermittent motion of the spatial non-holonomic multibody systems are developed in terms of coupled sets of reference and elastic co-ordinates. The intermittent motion behavior of the no...

A comparative study of the simulation algorithms for dynamics of large space structures modeled as a collection of rigid multibodies connected by hinges is described. Two algorithms have been independently developed at two research institutes. One method ...

A convergence and stability result is presented for a class of penalty formulations of multibody dynamics. Despite the fact that the governing equations are nonlinear, the theoretical convergence of the formulation is guaranteed if the multibody system is natural and conservative. Unfortunately, the convergence theorem-theorem is not ...

Jan 22, 2011 ... Monterey, CA, USA. Abstract: In this paper we develop the coupled orbital/ attitude dynamics of a multi-body solar sail spacecraft ...

... H LN Virgin, PV Bayly, KD Murphy, J. A ... Intermittent Motion Analysis in Multibody Dynamics Using Joint ... need to transform the equation, (Such as. ...

... However, the values for the discs ... 75. Markolf, KL, and Steidal, RF Jr., "The Dynamic Characteristics of Human Intervertebral Joint", ASME paper no. ...

Jain Publishes Robot Dynamics Book (12/10/2010) JPL Senior Research Scientist Abhinandan Jain has published a book entitled, Robot and Multibody Dynamics ...

... S., Shabana, AA, and Hwang, YL, "Dynamics and Motion Control of Space Cranes," Presented at the 7th International Conference on Advanced ...

... Efficient computer simulations were achieved by developing a FORTRAN program and using Dynamic Simulation Language (DSL). ...

A study for validating a time-accurate explicit finite element code for modeling fully-coupled flexible multibody systems carrying liquid-filled tanks is presented. The multibody system includes rigid bodies, flexible bodies, joints, and actuators. Rigid ...

A combined multibody and finite element approach is given to solve the dynamic interaction of a Shinkansen train (high-speed train in Japan) and the railway structure including post-derailment during an earthquake effectively. The motion of the train is expressed in multibody dynamics. Efficient mechanical models ...

Research on multibody dynamics in engineering and science is developing at a high pace in Japan and in the world. These activities provide efficient and powerful solution tools for solving complicated dynamic problems with control via theoretical or high performance in-house and/or general purpose computer programs in academic and ...

Accelerations Velocities. Musculoskeletal Geometry Multibody Dynamics Forces d dt d dt Force Data Angles #12;Open Geometry Multibody Dynamics Forces d dt d dt Force Data Angles FxFy Fz MxMy Mz 3 Forces 3 Moments #12;Open Geometry Multibody Dynamics Forces d dt d dt Force ...

A superelement formulation capable of handling large finite rotations is developed. It is based on a small rotation and displacement hypothesis in a local frame to the superelement. A standard component mode approach is adopted together with a lumped mass...

Keywords, code: WOBBE multibody dynamics aircraft: Masquito M80. Abstract � Address � Corporate Author � Place of Publication � Conference, Twenty-Sixth ...

... Examples of such domains include physical games, such as robot soccer, where the controlled robot has to deliver the ball into the opponent's goal ...

... Personal Author(s) : Bauchau, Olivier A. ; Choi, Jou-Young ; Bottasso, Carlo L. Handle / proxy Url : Report Date : NOV 2000. ...

integration. The building block equations are derived by applying Newton's and Euler's equations of motion to an "element" consisting of two bodies and one ...

Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC) 37th Design Automation Conference (DAC) 11th ASME International Power Transmission and Gearing Conference...

... articulated soft-inplane (SASIP) rotor system, designed as a potential can- didate for future heavy-lift rotorcraft, was tested at model scale on the ...

... translation between the respective bodies of the ... study of human/neck systems in high ... coordinates, relative coordinates, and body connection arrays ...

... The AGMA J factor and Lewis parabola methods are gear design and stress estimation methods commonly used in the gearing industry. ...

... To address the foregoing needs, the part of our research dealing with multi-body interactions we performed research to study store interaction with ...

framework by using a single instruction multiple data computation paradigm .... velocity of the body is simply ?rj, where an overdot represents time differentiation. ...

... 28 Figure 9 SIMULINK Model for Determining Rigid Body Acceleration of Transmitter and Receiver, using Equation 22 and Equation 23..... ...

... Title : Automated Methods for Converting a Non Real-time Cartesian Multi-body Vehicle Dynamics Model to a Real-time Recursive Model. ...

Jan 22, 2011 ... Aug-2005, PyCraft: A unifying multibody dynamics algorithm development workbench , Ziegler, John; Abhinandan, Jain ...

An order (n) multiflex body Space Station simulation tool is introduced. The flex multibody modeling

In this paper, the dynamic behavior of a multibody system including very flexible beam elements is presented. The very deformable motion of a beam is demonstrated using absolute nodal coordinate formulation, which is based on finite element procedures, and the general continuum mechanics theory to represent the elastic forces. In order to consider the ...

The following validation study analyzes rigid multibody dynamic the US Army's High Mobility Multipurpose Wheeled Vehicle (HMMWV) using the Dynamic Analysis and Design System (DADS) computer code and the US Army's Vehicle Dynamic Module (VEHDYN) computer c...

A multibody system consisting of rigid bodies, flexible bodies and various joints is called a flexible multibody system. When constructing a numerical model of a flexible multibody system, the simulation tool needs to be able to adequately represent the physical characteristics of the system. In particular, structural flexibility plays ...

The Articulated Total Body (ATE) is a rigid body dynamics computer model of the human body used at the Armstrong Laboratory (AL). The model is used to predict the kinetic response of the human body in different dynamic environments such as aircraft pilot ...

Methods developed for analysis of intermittent motion, flexible system dynamics, design sensitivity, and differential-algebraic equations are summarized. New techniques for dynamics of multibody flexible systems include mixed vibration and static correcti...

All essential existing capabilities needed to create a man-machine interaction dynamics and performance (MMIDAP) capability are reviewed. The multibody system dynamics software program Order N DISCOS will be used for machine and musculo-skeletal dynamics ...

The pantograph-catenary system, used for collecting electric energy in high-speed trains should ideally run with low contact forces but without contact loss. Not only defects on the overhead equipment, environmental conditions become more important as the operational speed increases but also the flexibility of the pantograph components may play a role on the overhead contact. In this work a ...

are evaluated by performing thousands of multibody dynamic wear simulations for a total knee replacement (TKR studies. For stochastic sensitivity studies of wear in knee replacements, the mean value method [57] has). This finding is consistent with two previous studies that performed probabilistic analyses of knee replacement

A general method for the dynamic analysis of multi-body offshore structures is presented, based on a constraint matrix approach. A method of deriving the constraint matrix for a general structure is given, and used to derive the equations of motion of a whole system from those of it's component parts. The response of the system to both first and ...

The augmented Lagrangian formulation used in the dynamic analysis of multibody systems under holonomic constraints is presently found to exhibit fixed-step convergence, so that the approximate accelerations and Lagrange multipliers at a fixed time interval approach the exact accelerations and multipliers as the number of iterations becomes large. Also ...

A model for the ergometer rowing exercise is presented in this paper. From the quantitative observations of a particular trajectory (motion), the model is used to determine the moment of the forces produced by the muscles about each joint. These forces are evaluated according to the continuous system of equations of motion. An inverse dynamics analysis is performed in order to ...

A new optimization method based on the fatigue life of multi-body structure is proposed in this paper with the computeraided engineering software. Taking the nose landing gear of some aero transports as an example, the loading history of the nose landing gear is firstly gained by the multi-body dynamics simulation, and then the fatigue ...

In Part 1 the spatial system kinematic and dynamic equations are developed using the Cartesian and elastic coordinates in order to maintain the generality of the formulation. This allows introducing general forcing functions and adding and/or deleting kin...

In this paper we develop the coupled orbital/attitude dynamics of a multi-body solar sail spacecraft

In Part I of this paper the kinematic relationships between the absolute, elastic and joint accelerations are developed. In this paper, these kinematic equations are used with the generalized Newton Euler equations and the relationship between the actual ...

The molecule modeling method known as Multibody Order (N) Dynamics, or MBO(N)D, was developed by Moldyn, Inc. at Goddard Space Flight Center through funding provided by the SBIR program. The software can model the dynamics of molecules through technology ...

A time-accurate finite element model for predicting the coupled dynamic response of tanker trucks and their liquid payloads is presented along with an experimental validation of the model. The tanker truck components are modeled using rigid bodies, flexib...

In this reprint the effect of member initial curvature on the dynamic response of mechanisms consisting of interconnected rigid and deformable links is investigated. In Euler-Bernoulli theory for straight beams it is assumed that there is no coupling betw...

The dynamic analysis of three dimensional elastic beams which experience large rotational and large deformational motions are examined. The beam motion is modeled using an inertial reference for the translational displacements and a body-fixed reference f...

In this paper, parallel O(log n) algorithms for computation of rigid multibody dynamics are developed. These parallel algorithms are derived by parallelization of new O(n) algorithms for the problem. The underlying feature of these O(n) algorithms is a dr...

An order (n) multiflex body Space Station simulation tool is introduced. The flex multibody modeling is generic enough to model all phases of Space Station from build up through to Assembly Complete configuration and beyond. Multibody subsystems such as t...

This work provides a generalization of Evans� homogeneous nonequilibrium method for estimating thermal conductivity to molecular systems that are described by general multibody potentials. A perturbed form of the usual Nose-Hoover equations of motion is formally constructed and is shown to satisfy the requirements of Evans� original method. These include adiabatic ...

for a bearingless rotor with active trailing edge flaps using a finite-element based multibody code, CAMRAD II mechanisms considered as a simplified model of an active helicopter rotor blade connecting to the hub. and Charles, B. D., "Aeroelastic analysis of rotors with trailing edge flaps using comprehensive codes

Typical undergraduate mechanical engineering curricula in North America do not include a course in multi-body dynamics. A rigid body dynamics course covering single-body kinetics is usually completed in early semesters, and often the material is not revisited before graduation. Students typically graduate without a sense of how to ...

We present a strain-based finite-element formulation for the dynamic analysis of flexible elastic planar multibody systems, composed of planar beams. We consider finite displacements, rotations and strains. The discrete dynamic equations of motion are obtained by the collocation method. The strains are the basic interpolated variables, ...

Multibody Dynamic Simulation has been used to successfully simulate a wide variety of military vehicles and predict the safety, mobility, stability, and operating loads of the complete system. The objective is to predict accurate vehicle behavior under any operating condition and provide the basis for making engineering design changes to improve ...

The present talks deals with a uniform approach to the discretization in time of rigid body dynamics, nonlinear structural mechanics and flexible multibody systems. In particular, it is shown that a uniform set of differential-algebraic equations (DAEs) with constant mass matrix governs the motion of rigid bodies and semi-discrete formulations of ...

The principle of virtual work is used to derive the Euler-Lagrange equations of motion in order to describe the dynamics of multibody android systems. The constrained variational equations are in fact differential-algebraic equations of high index and are cast as ordinary differential equations through differentiation of the constraint equations. The ...

This paper presents a formulation for incorporating nonlinear viscoelastic bushing elements into multibody systems. The formulation is based on the assumption that the relaxation function can be expressed as a sum of functions which are nonlinear in deformation and exponentially decreasing in time. These forces can represent elastomeric mounts or bushings in automotive ...

The virtual prototypes of gear transmission system built in most multi-body dynamic software have difficulties in describing the gear mesh characteristics. The gear mesh contact is modelled as rigid contact and this is not accurate for the gear mesh contact, which is elastic or flexible. The gear contact formula used in the multi-body ...

The kinematical and dynamical equations of motion were derived, as proposed by R.E. Roberson and J. Wittenburg, using the Newton-Euler equations. The result is a set of differential equations which may be used as the basis for establishing a general purpo...

Technology areas are identified in which better analytical and/or experimental methods are needed to adequately and accurately control the dynamic responses of multibody space platforms such as the space station. A generic space station solar panel is use...

The analysis of the efficiency of algorithms resulting from Kane's Equation for serial and parallel computation of mass matrix is examined. The algorithms resulting from Kane's equation and Modified Kane's equations are detailed. An analysis was made of t...

The 'Smart Adaptive Structures for Solar Sailcraft' development activity at MSFC has investigated issues associated with understanding how to model and scale the subsystem and multi-body system dynamics of a gossamer solar sailcraft with the objective of ...

Traditional motion planning focuses on the problem of safely navigating a robot through an obstacle-ridden environment. In this thesis, we address the question of how to perform robot motion planning in complex domains, with goals that go beyond collision...

... Inspired by real-world minigolf, the robot minigolf domain requires a robot to putt a golf ball into a hole by purposefully bouncing it off other obstacle ...

technical data and information deemed to be of continuing reference value. NASA's counterpart ..... The Green-Lagrange strain tensor e is defined as e = �( CYC - gT.q). ..... energy decay, using the EP scheme as a basic building ...

Occupant models are robust tools for gaining insight into the gross motion of ground vehicle or aircraft occupants and evaluating loads and deformations of their critical parts in the studies of crashworthiness. One of the most important issues in occupan...

The report describes the development of a finite element based multi- body contact analysis tool. This analysis tool is meant for use in the design of complex and flexible geared transmissions, such as those found in rotor-craft and automobiles. The techn...

Phase II of the SBIR project involves the implementation of all the features in the contract analysis software that would be necessary for it to be usable by gear design engineers.

Feb 25, 2009 ... Email: pierangelo.masarati at polimi.it. Contact Address: via La Masa 34. City: Milano Postal Code: 20156. Country: ITALY ...

Loads and stability calculations for a proposed unmanned tilt rotor aircraft are presented. Blade loads are calculated using the comprehensive analysis CAMRAD II and the multibody dynamics analysis DYMORE II for helicopter, airplane, transition, and maneu...

Outline: *Motivation. *Objective. *Literature Review. *FE Formulation: -Solid: Frictional contact model, Simple tire model, Detailed tire model. -Fluid; -Free-surface model; -Fluid-structure coupling. *Validation Study. *Concluding Remarks.

In this investigation, generalized Newton-Euler equations are developed for deformable bodies that undergo large translational and rotational displacements. The configuration of the deformable body is identified using coupled sets of reference and elastic...

The Weapons Analysis Branch, Ballistics and Weapons Concepts Division, Weapons and Materials Research Directorate of the U.S. Army Research Laboratory (ARL) built a multi-body engineering-level model of the unmanned ground vehicle platform used in the Off...

5. Jiang B-C, White JM. Effect of accommodative adaptation on static and dynamic accommodation in response to our ar- ticle describing methods to measure accommodative ampli- tude.1 They suggest that we measurements, subjects were distance corrected and could read the 20/20 Snellen line at 20 feet. ...

Due to increased available computer power, the analysis of nonlinear flexible multi-body systems, fixed-wing aircraft and rotary-wing vehicles is relying on increasingly complex, large scale models. An important aspect of the dynamic response of flexible multi-body systems is the potential presence of instabilities. Stability analysis ...

. In couplings of machines and mechanisms, backlash and friction phenomena are always occurring. Whether stick-slip phenomena take place depends on the structure of such couplings. These processes can be modeled as multibody systems with a timevarying topology. Making use of Lagrange multiplier methods with a mathematical formulation of the contact problem is very efficient ...

This research project has as its main goal the development of methods for selecting the damping characteristics of components of a large structure or multibody system, in such a way as to produce some desired system damping characteristics. The main need for such an analytical device is in the simulation of the dynamics of multibody ...

A dynamic simulation method for multi-body systems is presented in this paper. The special feature of this method is that it satisfies all given constraints by computing impulses. In each simulation step the joint states after the step are predicted. In order to obtain valid states after the simulation step, impulses are computed and applied to the ...

Changes in accommodative dynamics with repeated accommodation were studied in three anesthetized rhesus monkeys and two conscious humans. Maximum accommodation was centrally stimulated via the Edinger�Westphal nucleus in monkeys with a 4 s on, 4 s off paradigm (4 � 4) for 17 min, 4 � 1.5 for 27 min and 2 � ...

LDL \\Lambda decomposition of M \\Gamma1 . 7 Articulated Body Forward Dynamics Algorithm We first use. Assumed--mode models are used for the deformation of each individual body. The algorithms are based on two, and composite�body forward dynamics for the system. The second (Innovations) factorization of the mass matrix

With the fast development of the industry technology especially the applications of spacecraft and weapon systems, a great deal of problems come forth in the dynamics of flexible multibody system and should be settled urgently. Because of the facts of time-varying topologies in these systems, such as impact, friction, stiction, intermittent motion, lock-up ...

The advantageous combination of dynamical systems theory of three-body models with Electric Propulsion to design novel spacecraft mission in multi-body regimes has been investigated. Combining the advantages of Electric Propulsion with respect to propellant requirements and low-energy ballistic trajectories existing in the three-body model, ...

Simulation of the dynamics of physical systems is an important aspect of the engineering discipline for approximating the dynamics of real life. The simulation of complex multibody systems to an acceptable degree of accuracy involves the mathematical modeling and computer implementation of systems such as mechanisms and vehicles ...

Finite element based multibody dynamics formulations extend the applicability of classical finite element methods to the modeling of flexible mechanisms. A general computer code will include rigid and flexible bodies, such as beams, joints, and active elements. These procedures are designed to overcome the modeling limitations of conventional ...

The tiltrotor blade, or proprotor, acts as a rotor in the helicopter mode and as a propeller in the airplane mode. For a better performance, the proprotor should have different built-in twist distributions along the blade span, suitable for each operational mode. This paper proposes a new variable-twist proprotor concept that can adjust the built-in twist distribution for given flight modes. For a ...

Dynamic models for two space station configurations were derived. Space shuttle docking disturbances

Various papers on the stabilization of flexible structures are presented. Individual topics considered include: a theory of nonlinear damping in flexible structures, estimation of Boltzmann damping coefficients in beam models, stabilization of vibrating beams by a specific feedback, boundary control problem for a parabolic equation in noncylindrical domain, dynamical control ...

This paper presents a numerical framework for the simulation of dynamic fracture of heterogeneous material. It consists in a multibody approach based both on the concept of Frictional Cohesive Zone Model and on NonSmooth Contact Dynamics. The heterogeneities of the material are taken into account using a multiscale method. The ...

02.05-1050A Mechanisms of Energy Accommodation on Catalytic Surfaces Chemical Dynamics Corporation 9560 Pennsylvania Avenue Upper Marlboro MD 20772 Bruce C. ...

Presented here is a camera-based noncontact measurement theory for static/dynamic testing of flexible multibody systems that undergo large rigid, elastic and/or plastic deformations. The procedure and equations for accurate estimation of system parameters (i.e. the location and focal length of each camera and the transformation matrix relating its image ...

Basic performance requirements for space-based directed energy weapons involve unprecedented requirements for integrated control of rapid retargeting and precision pointing of space structures. Multibody interactions excite nonlinear couplings which complicate the dynamic response. Attempts to reduce flexure response for such weapon platforms by passive ...

We have enhanced our parallel molecular dynamics (MD) simulation software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator, lammps.sandia.gov) to include many new features for accelerated simulation including articulated rigid body dynamics via coupling to the Rensselaer Polytechnic Institute code POEMS (Parallelizable Open-source ...

A mixed flexible-rigid multi-body model is presented to study the dynamic behavior of a horizontal axis wind turbine. The special attention is given to flexible body: flexible rotor is modeled by a newly developed blade finite element, support bearing elasticities, variations in the number of teeth in contact as well as contact tooth's elasticities are ...

This paper describes a new formulation of the equations of motion for a system of connected rigid bodies. The bodies may either be hinge or slide connected. The connection topology is assumed to be that of a tree. Starting with the Newton-Euler equations of motion, the equations are transformed into a new system of equations using generalized velocity coordinates (both translational and ...

Modeling of multibody systems is an important though demanding field of application for interval arithmetic. Interval modeling of dynamics is particularly challenging, not least because of the differential equations which have to be solved in the process. Most modeling tools transform these equations into a (non-autonomous) initial value problem, interval ...

L-697 Stability of the Parisi solution for Heisenberg spin glasses A. V. Goltsev A. F. Ioffe'existence de modes sans masse. Abstract. 2014 For the Heisenberg spin glasses (the Sherrington, Classification Physics Abstracts 75.40 Much effort has been devoted to the infinite-ranged model of a spin glass

The twenty-three papers contained in this volume document the strides made in a number of aspects of symbolic computations. The topic headings in the symposium are largely represented by the six section headings of this volume, namely: Construction of Symbolic Manipulation Systems and Commercial Systems; Coupling of Symbolic Manipulation and Numerical programs; Applications to Structural Mechanics ...

The Spectral Gap of the REM under Metropolis Dynamics L. R. G. Fontes Universidade de S~ao Paulo M to equilibrium, spectral gap, dynamical phase transition 1 #12; 1 Introduction The Random Energy Model (REM)([1], [2 only, in the REM there are gaussian multibody interactions. The hamiltonian for the SK model is (for oe

successful object segmentation, which cannot always be ac� complished reliably (e.g., under camouflage a waterfall. Our claim is that in these cases we can still observe a dynamic sequence of abrupt changes have a dynamic size, i.e., the particle size varied during tracking in order to optimally fit itself

and second body of joint i respectively. Since the decomposition A = CM-1 CT is known, the SLE-based dynamic simulation method for articulated bodies which has a linear time com- plexity. Existing linear is not neces- sary. The presented method computes a simulation step in O(n) time for acyclic multi-body systems

A new multi-body energy function is constructed to reproduce protein structure from sequence. As a benchmark test of the method, low energy structures of [alpha], [alpha]/[beta], and [beta] proteins are searched with the Langevin molecular dynamics calculation. Similarities among thus generated structures and the native ones showed that the present ...

The dynamics of Edinger-Westphal (EW) stimulated accommodation were studied in two young rhesus monkeys to understand the relationships between accommodative amplitude and rates of accommodation and disaccommodation. Accommodative responses were recorded with infrared photorefraction at five ...

Finite element methods (FEM) employing the arbitrary Lagrangian-Eulerian (ALE) formulation may be used to model soil in contact with the wheels or the tracks of vehicles in off-road mobility simulations. Coupling ALE finite element methods with recursive multi-body dynamics may allow real-time simulation of vehicles off-road provided sufficient ...

Finite element methods (FEM) employing the arbitrary Lagrangian-Eulerian (ALE) formulation may be used to model soil in contact with the wheels or the tracks of vehicles in off-road mobility simulations. Coupling ALE finite element methods with recursive multi-body dynamics may allow real-time simulation of vehicles off-road provided sufficient ...

This work developed a free/open source simulation software for wind turbines, based on coupling a free general-purpose multibody dynamics software developed at Politecnico di Milano, Italy, with an open-source software library for wind turbine aerodynamics developed by the National Renewable Energy Laboratory (NREL) in USA. The verification results show ...

PURPOSEWhen the aging lens is replaced with prosthetic accommodating intraocular lenses (IOLs), with effective viscoelasticities different from those of the natural lens, mismatches could arise between the neural control of accommodation and the biomechanical properties of the new lens. These mismatches could lead to either unstable oscillations or ...

We report the calculation of the coexisting densities and surface tensions of the liquid-vapor equilibrium using the multibody dissipative particle dynamics and Monte Carlo (MMC) methods. We focus on the calculation of the surface tension by using the thermodynamic and mechanical routes. It is the first time that the test-area method is applied on the ...

We report the calculation of the coexisting densities and surface tensions of the liquid-vapor equilibrium using the multibody dissipative particle dynamics and Monte Carlo (MMC) methods. We focus on the calculation of the surface tension by using the thermodynamic and mechanical routes. It is the first time that the test-area method is applied on the ...

Three types of multibody models are presented for the investigation of the internal dynamics of a drive train in a wind turbine. The first approach is limited to the analysis of torsional vibrations only. Then a rigid multibody model is presented with special focus on the representation of the bearings and gears in the drive train. The ...

This work presents a general three-dimensional multibody procedure for studying the human body motion with emphasis on the locomotion apparatus. The methodology includes a three-dimensional biomechanical model, data acquisition techniques and an inverse dynamics approach. The biomechanical model is based on a multibody formulation ...

Head and eye movements, together with ocular accommodation enable us to explore our visual environment. The stability of this environment is maintained during saccadic and vergence eye movements due to reduced contrast sensitivity to low spatial frequency information. Our recent work has revealed a new type of selective reduction of contrast sensitivity to high spatial ...

A dynamic model of ocular accommodation is used to simulate the stability and dynamic performance of accommodating intraocular lenses (A-IOLs) that replace the hardened natural ocular lens that is unable to change focus. Accommodation simulations of an older eye with A-IOL materials having ...

The multibody dynamics of the Space Station is studied as affected by the suntracking motions of the photovotaic arrays. Dynamic responses are simulated for the Station being controlled by control moment gyros (CMGs). Controllability is shown to be a function of flight orientation, stage (inertial properties, CP-CG offset) and the ...

Dynamic Accessibility: Detecting and Accommodating Differences in Ability and Situation Abstract Human abilities are idiosyncratic and may change frequently. Static one-size-fits-many accessibility solutions miss the opportunities that arise from careful consideration of an individual's abilities and fail

PurposeSome debate surrounds the accommodative mechanism in primates, particularly whether the lens equatorial diameter increases or decreases during accommodation. This study has been undertaken to measure the relationship between changes in lens diameter and refraction during accommodation in rhesus monkeys.MethodsPhotorefraction was ...