Model reduction for the material point method via an implicit neural representation of the deformation map

التفاصيل البيبلوغرافية
العنوان: Model reduction for the material point method via an implicit neural representation of the deformation map
المؤلفون: Chen, Peter Yichen, Chiaramonte, Maurizio M., Grinspun, Eitan, Carlberg, Kevin
سنة النشر: 2021
المجموعة: Computer Science
Mathematics
مصطلحات موضوعية: Computer Science - Machine Learning, Computer Science - Computational Engineering, Finance, and Science, Computer Science - Graphics, Mathematics - Numerical Analysis
الوصف: This work proposes a model-reduction approach for the material point method on nonlinear manifolds. Our technique approximates the $\textit{kinematics}$ by approximating the deformation map using an implicit neural representation that restricts deformation trajectories to reside on a low-dimensional manifold. By explicitly approximating the deformation map, its spatiotemporal gradients -- in particular the deformation gradient and the velocity -- can be computed via analytical differentiation. In contrast to typical model-reduction techniques that construct a linear or nonlinear manifold to approximate the (finite number of) degrees of freedom characterizing a given spatial discretization, the use of an implicit neural representation enables the proposed method to approximate the $\textit{continuous}$ deformation map. This allows the kinematic approximation to remain agnostic to the discretization. Consequently, the technique supports dynamic discretizations -- including resolution changes -- during the course of the online reduced-order-model simulation. To generate $\textit{dynamics}$ for the generalized coordinates, we propose a family of projection techniques. At each time step, these techniques: (1) Calculate full-space kinematics at quadrature points, (2) Calculate the full-space dynamics for a subset of `sample' material points, and (3) Calculate the reduced-space dynamics by projecting the updated full-space position and velocity onto the low-dimensional manifold and tangent space, respectively. We achieve significant computational speedup via hyper-reduction that ensures all three steps execute on only a small subset of the problem's spatial domain. Large-scale numerical examples with millions of material points illustrate the method's ability to gain an order of magnitude computational-cost saving -- indeed $\textit{real-time simulations}$ -- with negligible errors.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2109.12390
رقم الانضمام: edsarx.2109.12390
قاعدة البيانات: arXiv