The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Edward Cater - One of the best experts on this subject based on the ideXlab platform.
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Implicit Time Integration for pseudodynamic tests
Earthquake Engineering & Structural Dynamics, 1991Co-Authors: P. B. Shing, Mani T. Vannan, Edward CaterAbstract:The use of unconditionally stable implicit Time Integration techniques for pseudodynamic tests has been recently proposed and advanced by several researchers. Inspired by such developments, a pseudodynamic test scheme based on an unconditionally stable implicit Time Integration algorithm and dual displacement control is presented in this paper. The accuracy of the proposed scheme is proved with error-propagation analysis. It is shown by numerical examples and verification tests that the error-correction method incorporated can eliminate the spurious higher-mode response, which can often be excited by experimental errors. The practicality of the proposed scheme lies in the fact that the implementation is as easy as that of explicit schemes and that the convergence criteria required are compatible with the accuracy limits of ordinary test apparatus.
Klaus-jürgen Bathe - One of the best experts on this subject based on the ideXlab platform.
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Crushing and crashing of tubes with implicit Time Integration
International Journal of Impact Engineering, 2012Co-Authors: Zafer Kazancı, Klaus-jürgen BatheAbstract:Abstract The axial crushing and crashing of thin-walled high-strength steel tubes is performed using 3D-shell finite elements and an implicit Time Integration scheme. The calculated results are compared with published experimental data and results obtained using explicit Time Integration. The objective is to show that, while for such analyses generally explicit Time Integration is used, with the current state of the art also an implicit Time Integration solution should be considered, and such solution approach can provide an effective alternative for a simulation.
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conserving energy and momentum in nonlinear dynamics a simple implicit Time Integration scheme
Computers & Structures, 2007Co-Authors: Klaus-jürgen BatheAbstract:We focus on a simple implicit Time Integration scheme for the transient response solution of structures when large deformations and long Time durations are considered. Our aim is to have a practical method of implicit Time Integration for analyses in which the widely used Newmark Time Integration procedure is not conserving energy and momentum, and is unstable. The method of Time Integration discussed in this paper is performing well and is a good candidate for practical analyses.
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on a composite implicit Time Integration procedure for nonlinear dynamics
Computers & Structures, 2005Co-Authors: Klaus-jürgen Bathe, Mirza Irfan M BaigAbstract:Transient analysis of nonlinear problems in structural and solid mechanics is mainly carried out using direct Time Integration of the equations of motion. For reliable solutions, a stable and efficient Integration algorithm is desirable. Methods that are unconditionally stable in linear analyses appear to be a natural choice for use in nonlinear analyses, but unfortunately may not remain stable for a given Time step size in large deformation and long Time range response solutions. A composite Time Integration scheme is proposed and tested in some example solutions against the trapezoidal rule and the Wilson @q-method, and found to be effective where the trapezoidal rule fails to produce a stable solution. These example results are indicative of the merits of the composite scheme.
Kuan-chou Chen - One of the best experts on this subject based on the ideXlab platform.
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Improved Time Integration for pseudodynamic tests
Earthquake Engineering & Structural Dynamics, 1998Co-Authors: Shuenn-yih Chang, Keh-chyuan Tsai, Kuan-chou ChenAbstract:Converting the second-order differential equation to a first-order equation by integrating it with respect to Time once as the governing equation of motion for a structural system can be very promising in the pseudodynamic testing. This was originally found and developed by Chang. The application of this Time-Integration technique to the Newmark explicit method is implimented and investigated in this paper. The main advantages of using the integral form of Newmark explicit method instead of the commonly used Newmark explicit method in a pseudodynamic test are: a less-error propagation effect, a better capability in capturing the rapid changes of dynamic loading and in eliminating the adverse linearization errors. All these improvements have been verified by theoretical studies and experimental tests. Consequently, for a same Time step this Time-Integration technique may result in less-error propagation and achieve more accurate test results than applying the original form of Newmark explicit method in a pseudodynamic test due to these significant improvements. Thus, the incorporation of this proposed Time-Integration technique into the direct Integration method for pseudodynamic testings is strongly recommended. © 1998 John Wiley & Sons, Ltd.
Patrick Le Tallec - One of the best experts on this subject based on the ideXlab platform.
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Energy-controlling Time Integration methods for nonlinear elastodynamics and low-velocity impact
Computer Methods in Applied Mechanics and Engineering, 2006Co-Authors: Patrice Hauret, Patrick Le TallecAbstract:It is now well established that discrete energy conservation/dissipation plays a key-role for the unconditional stability of Time Integration schemes in nonlinear elastody-namics. In this paper, from a rigorous conservation analysis of the Hilber-Hughes-Taylor Time Integration scheme [1], we propose an original way of introducing a controllable energy dissipation while conserving momenta in conservative strategies like [2–5]. Moreover, we extend the technique proposed in [3] to provide energy-controlling Time Integration schemes for frictionless contact problems enforcing the standard Kuhn-Tucker conditions at Time discretization points. We also extend this technique to viscoelastic models. Numerical tests involving the impact of incompressible elastic or viscoelastic bodies in large deformation are proposed to confirm the theoretical analysis.
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Energy-controlling Time Integration methods for nonlinear elastodynamics and low-velocity impact
Computer Methods in Applied Mechanics and Engineering, 2006Co-Authors: Patrice Hauret, Patrick Le TallecAbstract:It is now well established that discrete energy conservation/dissipation plays a key-role for the unconditional stability of Time Integration schemes in nonlinear elastodynamics. In this paper, from a rigorous conservation analysis of the Hilber–Hughes–Taylor Time Integration scheme [H. Hilber, T. Hughes, R. Taylor, Improved numerical dissipation for Time Integration algorithms in structural dynamics, Earthquake Engrg. Struct. Dynam. 5 (1977) 283–292], we propose an original way of introducing a controllable energy dissipation while conserving momenta in conservative strategies like [J. Simo, N. Tarnow, The discrete energy–momentum method: conserving algorithms for nonlinear elastodynamics, Z. Angew. Math. Phys. 43 (1992) 757–792]. Moreover, we extend the technique proposed in [O. Gonzalez, Exact energy and momentum conserving algorithms for general models in nonlinear elasticity, Comput. Methods Appl. Mech. Engrg. 190 (13–14) (2000) 1763–1783] to provide energy-controlling Time Integration schemes for frictionless contact problems enforcing the standard Kuhn–Tucker conditions at Time discretization points. We also extend this technique to viscoelastic models. Numerical tests involving the impact of incompressible elastic or viscoelastic bodies in large deformation are proposed to confirm the theoretical analysis.
P. B. Shing - One of the best experts on this subject based on the ideXlab platform.
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Implicit Time Integration for pseudodynamic tests
Earthquake Engineering & Structural Dynamics, 1991Co-Authors: P. B. Shing, Mani T. Vannan, Edward CaterAbstract:The use of unconditionally stable implicit Time Integration techniques for pseudodynamic tests has been recently proposed and advanced by several researchers. Inspired by such developments, a pseudodynamic test scheme based on an unconditionally stable implicit Time Integration algorithm and dual displacement control is presented in this paper. The accuracy of the proposed scheme is proved with error-propagation analysis. It is shown by numerical examples and verification tests that the error-correction method incorporated can eliminate the spurious higher-mode response, which can often be excited by experimental errors. The practicality of the proposed scheme lies in the fact that the implementation is as easy as that of explicit schemes and that the convergence criteria required are compatible with the accuracy limits of ordinary test apparatus.
