New aspects of the CISAMR algorithm for meshing domain geometries with sharp edges and corners

Abstract

Several new algorithmic aspects of the conforming to interface structured adaptive mesh refinement (CISMAR) mesh generation technique are presented for creating high-fidelity finite element models of 3D problems with non-smooth (C0–continuous) geometries. The Stereolithography (STL) file characterizing the domain geometry is first pre-processed to identify its sharp edges and corners, followed by overlaying that on a structured background mesh composed of tetrahedral elements to identify elements cuts by material interfaces/boundaries. Three non-iterative algorithms, namely hierarchical r-adaptivity, element deletion, and Kirigami-inspired sub-tetrahedralization are then introduced to generate a high-quality conforming mesh by relocating background mesh nodes, eliminating degenerate elements, and subdividing non-conforming tetrahedra to match material interfaces and domain boundaries. These algorithms either upgrade or fully replace different phases of the original CISAMR technique, which was limited to modeling problems with smooth interfaces. The example problems provided in this manuscript demonstrate the upgraded CISAMR algorithm to handle domain geometries with complex, non-smooth interfaces.