Three-dimensional transient elastodynamic inversion using the modified error in constitutive relation

4th International Workshop on New Computational Methods for Inverse Problems

物理学;计算机科学

Bonnet, Marc^1 ; Aquino, Wilkins^2

POems, UMR 7231 CNRS-INRIA-ENSTA, ENSTA, Palaiseau, France^1

Department of Civil and Environmental Engineering, Duke University, Durham, United States^2

关键词: 3d configurations;    Computational bottlenecks;    Computational procedures;    Constitutive relations;    Cost functionals;    Inversion algorithm;    SOR-like method;    Time stepping algorithms;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/542/1/012003/pdf
DOI  :  10.1088/1742-6596/542/1/012003

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

This work is concerned with large-scale three-dimensional inversion under transient elastodynamic conditions by means of the modified error in constitutive relation (MECR), an energy-based cost functional. A peculiarity of time-domain MECR formulations is that each evaluation involves the computation of two elastodynamic states (one forward, one backward) which moreover are coupled. This coupling creates a major computational bottleneck, making MECR-based inversion difficult for spatially 2D or 3D configurations. To overcome this obstacle, we propose an approach whose main ingredients are (a) setting the entire computational procedure in a consistent time-discrete framework that incorporates the chosen time-stepping algorithm, and (b) using an iterative SOR-like method for the resulting stationarity equations. The resulting MECR-based inversion algorithm is demonstrated on a 3D transient elastodynamic example involving over 500,000 unknown elastic moduli.