FE2TI: Computational Scale Bridging for Dual-Phase Steels

A scale bridging approach combining the FE method with parallel domain decomposition (FETI) is presented. The FETI approach is used in the project “EXASTEEL Bridging Scales for Multiphase Steels” (within the German priority program “Software for Exascale Computing SPPEXA”) for the simulation of modern dual-phase steels. This approach incorporates phenomena on the microscale into the macroscopic problem by solving many independent microscopic problems on representative volume elements (RVEs). The results on the RVEs replace a phenomenological material law on the macroscale. In order to bring large micro-macro simulations to modern supercomputers, in the FETI approach a highly scalable implementation of the inexact reduced FETI-DP (Finite Element Tearing and Interconnecting Dual Primal) domain decomposition method (scalable up to 786 432 Mira BlueGene/Q cores) is used as a solver on the RVEs. Weak scalability results for the FETI method are presented, filling the complete JUQUEEN at JSC Jülich (458 752 cores) and the complete Mira at Argonne National Laboratory (786 432 cores).