Ratel: Performance portable solid mechanics with libCEED and PETSc

Ratel is a solid mechanics library and applications based on libCEED and PETSc with support for efficient high-order elements and CUDA and ROCm GPUs.

Solid mechanics simulations provide vital information for many engineering applications, using a large amount of computational resources from workstation to supercomputing scales. The industry standard for implicit analysis uses assembled sparse matrices with low-order elements, typically $Q_1$ hexahedral and $P_2$ tetrahedral elements, with the linear systems solved using sparse direct solvers, algebraic multigrid, or multilevel domain decomposition. This approach has two fundamental inefficiencies: poor approximation accuracy per Degree of Freedom (DoF) and high computational and memory cost per DoF due to choice of data structures and algorithms. High-order finite elements implemented in a matrix-free fashion with appropriate preconditioning strategies can overcome these inefficiencies. Integrating more efficient data structures and algorithms into solid mechanics software libraries can greatly improve engineering workflows and allow users to better utilize their computational resources while new technologies like Automatic Differentiation can be used to shorten development time.