PSI - Issue 83

Wong Kam Chee et al. / Procedia Structural Integrity 83 (2026) 14–27

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span angle, growth rate, and feature angle. Edge length controls the mesh element’s edge length, and it can be a single value or scalar field. As for the span angle, it controls the maximum allowed angle for the element lies on the curved surfaces to span. A smaller angle indicates the more refined curve of the element to fit the span angle. Growth rate controls the element size ratio from one to another where a smaller number indicates a more uniform mesh. Finally, feature angle controls the degree of the curved surfaces to convert to flat edges of the mesh. For this study, the top plate is meshed using the minimum feature size of 0.5mm, edge length of 0.5mm, growth rate of 2 and linear geometric order. The same mesh setting is applied to the bottom plate. A finite element volume mesh block is used to mesh the lattice body. The mesh size and edge length are set to 0.225mm, shape is set to a triangle shape with a span angle of 0.5 degrees, feature angle of 45 degrees, linear geometric order and a growth rate of 1.2. Next is the meshing of the lattice body. The tolerance and edge length of the mesh are set to 0.225mm with a triangular mesh shape and linear geometric order. The span angle. growth rate and feature angle are set to 15 degrees, 1.2, and 45 degrees, respectively. Table 1 shows the mesh quality, skewness, and orthogonality of the lattices with the edge length of 0.2mm. All the lattice displays a high average mesh quality of above 0.9, indicates that it is a good mesh. Even though the minimum mesh quality for hybrid is low at 0.0598, it can be ignored as the mesh is a small portion of the whole lattice. Skewness is recommended to fall in the range of 0 to 0.5 to be considered a good mesh. All the average skewness of the lattices falls within this range and is considered excellent meshing. The high maximum skewness of the lattices can be ignored as it is only a small portion of the whole lattice and will not affect the result much. Orthogonality measures the angles between the adjacent element faces to 90°. High orthogonality indicates elements are well-shaped and will provide a better result. All the lattices show a high orthogonality of above 0.9, which indicates good mesh is produced.

2 2.5 3 3.5 4 4.5 5 5.5 6 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 Von MIses Stress (x 10 4 MPa) Mesh Edge Length (mm)

Figure 2. Mesh Convergence

Table 1. Mesh quality, skewness, and orthogonality Aspects Lattice Min Max Ave

Schwarz P 0.4889 1

0.9666 0.9629 0.9219

Mesh Quality

Gyroid Hybrid

0.2153 1 0.0598 1

Schwarz P 0

0.7675 0.0499 0.8287 0.0552 0.9472 0.1124

Skewness

Gyroid Hybrid

0 0

Schwarz P 0.637

1

0.9785 0.9749 0.94649

Orthogonality

Gyroid Hybrid

0.4735 1 0.3279 1