Estimating the critical time‐step in explicit dynamics using the Lanczos method |
| |
| Authors: | J R Koteras R B Lehoucq |
| |
| Affiliation: | 1. Computational Solid Mechanics & Structural Dynamics, Sandia National Laboratories, MS 0380, P.O. Box 5800, Albuquerque, NM 87185‐0380, U.S.A.;2. Computational Mathematics & Algorithms, Sandia National Laboratories, MS 1110, P.O. Box 5800, Albuquerque, NM 87185‐1110, U.S.A.Computational Mathematics & Algorithms, Sandia National Laboratories, MS 1110, P.O. Box 5800, Albuquerque, NM 87185‐1110, U.S.A. |
| |
| Abstract: | The goal of our paper is to demonstrate the cost‐effective use of the Lanczos method for estimating the critical time step in an explicit, transient dynamics code. The Lanczos method can provide a significantly larger estimate for the critical time‐step than an element‐based method (the typical scheme). However, the Lanczos method represents a more expensive method for calculating a critical time‐step than element‐based methods. Our paper shows how the additional cost of the Lanczos method can be amortized over a number of time steps and lead to an overall decrease in run‐time for an explicit, transient dynamics code. We present an adaptive hybrid scheme that synthesizes the Lanczos‐based and element‐based estimates and allows us to run near the critical time‐step estimate provided by the Lanczos method. Copyright © 2006 John Wiley & Sons, Ltd. |
| |
| Keywords: | eigenvalues Lanczos iteration critical time step explicit dynamics |
|
|
