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Exponential time propagators for elastodynamics

delete2024-12-01
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PRE
AI
P
Paavai Pari
B
Bikash Kanungo
V
Vikram Gavini *
DOI:10.1016/j.jmps.2024.105871delete
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Abstract

Abstract

En 中文
We propose a computationally efficient and systematically convergent approach for elastodynamics simulations. We recast the second-order dynamical equation of elastodynamics into an equivalent first-order system of coupled equations, so as to express the solution in the form of a Magnus expansion. With any spatial discretization, it entails computing the exponential of a matrix acting upon a vector. We employ an adaptive Krylov subspace approach to inexpensively and accurately evaluate the action of the exponential matrix on a vector. In particular, we use an apriori error estimate to predict the optimal Krylov subspace size required for each time- step size. We show that the Magnus expansion truncated after its first term provides quadratic and superquadratic convergence in the time-step for nonlinear and linear elastodynamics, respectively. We demonstrate the accuracy and efficiency of the proposed method for one linear (linear cantilever beam) and three nonlinear (nonlinear cantilever beam, soft tissue elastomer, and hyperelastic rubber) benchmark systems. For a desired accuracy in energy, displacement, and velocity, our method allows for 10-100x larger time-steps than conventional time-marching schemes such as Newmark-fl method. Computationally, it translates to a similar to 1000x and similar to 10-100x speed-up over conventional time-marching schemes for linear and nonlinear elastodynamics, respectively.
Keywords:
Dynamics
Numerical algorithms
Exponential integrators

Journal

Journal of the Mechanics and Physics of Solids cover
Journal of the Mechanics and Physics of Solids
IF:
6
Papers:
5.2K
Citations:
3.0W

Organization

U
university of michigan system
Scholars:
9.1W
Papers: 8.6W
Citations: 133