Wave Propagation Simulation of Complex Multi-Material Problems with Fast Low-Order Unstructured Finite-Element Meshing and Analysis

Many wave-propagation analyses with varying geometries and material properties are expected to be useful for model optimization. Low-order unstructured finite-element methods are suitable for such analyses, as they are capable of modeling multi-material problems with complex geometries; however, the meshing and analysis cost is large. Therefore, in this paper, we developed a fast mesh-generator and analysis method. The robust mesh generator was 17.4-fold faster than a conventional mesh generator, and the predictor algorithm for dynamic implicit finite-element solvers showed a 1.69-fold increase in speed relative to conventional solvers and a 91.3% size-up efficiency on the full Oakforest-PACS system. We demonstrated the usability of the developed meshing and analysis methods via a wave-propagation simulation on a 1.9 billion unstructured tetrahedral-element model using half of the K computer system (41,472 compute nodes).