An enhanced approach to automatic decomposition of thin-walled components for hexahedral-dominant meshing

Abstract

Hexahedral (hex) meshes can be generated for CAD models of complex thin-walled components by isolating thin-sheet and long-slender regions, quad meshing one of the bounding faces, and sweeping the quad mesh through the volume to create hex elements. Continuing the work in Sun et al. (Proc Eng 163:225-237, 2016), where an improved approach to thin-sheet identification was presented, an enhanced automatic method for long-slender region identification is proposed in this paper. The objective is to improve the efficiency and decomposition quality compared to existing long-slender region identification processes. Geometric measures such as the edge length and the face width are employed to generate sizing measures, which are in turn used to identify candidate long-slender regions. Careful consideration is given to the generation and positioning of the cutting faces required to isolate the long-slender regions by assessing a priori quad mesh quality on the wall faces. It is shown that a significant reduction in the number of degrees of freedom (DOF) can be achieved by applying anisotropic hex elements on the identified regions.

Decomposing complex thin-walled CAD models for hexahedral-dominant meshing

“…It is clear the body with the curved face can also be meshed by sweeping, albeit with a sweep direction along the length of the body rather than in the thickness of the thin-sheet region. Using the approach described in [18] or [19] any long-slender regions in the non-thin sheet residual regions can be further identified. These regions can also be meshed with sweeping algorithms.…”

“…Robinson's work on identifying thin-sheet regions was extended by Makem et al [18] to find the long-slender regions in the solid bodies left behind after the thin-sheet extraction using a series of sizing measures. The notion of finding and exploiting long-slender regions was further enhanced by Sun et al for the purposes of hex mesh generation [19]. Whilst Robinson focused on generating decompositions for stiffened shell models, Makem et al utilized the thin decomposition to generate mixed solid element meshes by applying beam elements to the resulting long-slender regions.…”

“…12(f). While this reduces the overall volume identified as thin-sheet, it is shown in other work that the residual region can be identified as a long-slender region [19] or sweep-able volume [29], in which a high quality mesh can be produced using these other approaches.…”