Advanced General-Purpose Finite Element Solid Analysis System Adventure_Solid on the Earth Simulator: Its Application to Full-Scale Analysis of Nuclear Pressure Vessel

We have been developing an advanced general-purpose computational mechanics system, named ADVENTURE, which is designed to be able to analyze a model of arbitrary shape with a 10–100 million degrees of freedom (DOFs) mesh, and additionally to enable parametric and non-parametric shape optimization. Domain-decomposition-based parallel algorithms are implemented in pre-processes (domain decomposition), main processes (system matrix assembling and solutions) and post-process (visualization), respectively. Especially the hierarchical domain decomposition method with a preconditioned iterative solver (HDDM) is adopted in one of the main modules for solid analysis, named ADVENTURE_Solid. The employed preconditioner is the Balancing Domain Decomposition (BDD) type method. The ADVENTURE_Solid has been successfully implemented on a single PC, PC clusters and massively parallel processors such as Hitachi SR8000/MPP. In this study, this solid analysis module is implemented with minor modification on the Earth Simulator consisting of 256 nodes, i.e. 2,048 vector-type processing elements of theoretical peak performance of 16 TFLOPS (Tela FLoating point Operations Per Seconds), and succeeded in solving an elastostatic problem of a nuclear pressure vessel model of 100 million DOFs mesh in 8.5 minutes with 5.1 TFLOPS, which is 31.8% of the peak performance and over 80% parallel efficiency. As the purpose of demonstration of virtual mock-up test, the ADVENTURE_Solid is applied to solve a precise model of the ABWR vessel subjected to two kinds of loading conditions, i.e. (1) quasi-static seismic loading and (2) hydrostatic internal pressure.