Krysl, P. and Lall, S. and Marsden, J. E. (2001) Dimensional model reduction in non-linear finite element dynamics of solids and structures. International Journal for Numerical Methods in Engineering, 51 (4). pp. 479-504. ISSN 0029-5981 http://resolver.caltech.edu/CaltechAUTHORS:20100820-113408535
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A general approach to the dimensional reduction of non-linear finite element models of solid dynamics is presented. For the Newmark implicit time-discretization, the computationally most expensive phase is the repeated solution of the system of linear equations for displacement increments. To deal with this, it is shown how the problem can be formulated in an approximation (Ritz) basis of much smaller dimension. Similarly, the explicit Newmark algorithm can be also written in a reduced-dimension basis, and the computation time savings in that case follow from an increase in the stable time step length. In addition, the empirical eigenvectors are proposed as the basis in which to expand the incremental problem. This basis achieves approximation optimality by using computational data for the response of the full model in time to construct a reduced basis which reproduces the full system in a statistical sense. Because of this ‘global’ time viewpoint, the basis need not be updated as with reduced bases computed from a linearization of the full finite element model. If the dynamics of a finite element model is expressed in terms of a small number of basis vectors, the asymptotic cost of the solution with the reduced model is lowered and optimal scalability of the computational algorithm with the size of the model is achieved. At the same time, numerical experiments indicate that by using reduced models, substantial savings can be achieved even in the pre-asymptotic range. Furthermore, the algorithm parallelizes very efficiently. The method we present is expected to become a useful tool in applications requiring a large number of repeated non-linear solid dynamics simulations, such as convergence studies, design optimization, and design of controllers of mechanical systems.
|Additional Information:||© 2001 John Wiley & Sons, Ltd. Article first published online: 22 MAR 2001. Received 4 April 2000. Revised 1 August 2000. We thank Peter Schröder, John Doyle, and Ronald Coifman for helpful comments and inspiration. The research of SL was partially supported by AFOSR MURI grant F49620-96-1-0471, that of PK was partially supported by NSF/DARPA/Opaal grant DMS-9874082 and the research of JEM was partially supported by NSF-KDI grant ATM-98-73133.|
|Subject Keywords:||solid dynamics;finite element method;Ritz basis;model dimension reduction;empirical eigenvectors;Karhunen–Loève expansion|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||23 Aug 2010 21:30|
|Last Modified:||26 Dec 2012 12:20|
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