A new stress-driven composite porous structure design method based on triply periodic minimal surfaces. (December 2022)

• Record Type: Journal Article
• Authors: Liu, Bin; Liu, Meiying; Cheng, Huaqin; Cao, Wei; Lu, Ping
• Is Part Of: Thin-walled structures. Volume 181(2022)
• Publication Date: 2022-12
• Subjects: Composite porous structure -- Stress mapping -- Triply periodic minimal surfaces -- Geodesic Voronoi tessellations -- Closed geodesic B-spline curves; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2022.109974
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: Replacing the solid infills with porous structure infill is a reliable method in the field of 3D-printed model lightweight. Triply periodic minimal surfaces (TPMSs) provide a smooth and fully connected porous structure and can be mathematically described, making itself an ideal infilling structure for lightweight design. In this paper, a design method of composite porous structure based on TPMSs is proposed, which takes the multi-scale bionic porous structure for reference, performs the stress-driven weighted random sampling on the basis of the finite element analysis results, and combines the offset geodesic B-splines with the Geodesic Voronoi Tessellations (GVT). The method can not only optimize the structure by reasonably selecting the inherent parameters of TPMSs, but also can realize the mechanical optimization by controlling the distribution of Voronoi sites and the offsetting weight of the geodesic B-splines based on the stress distribution. Both the Finite Element Analysis (FEA) results and mechanical experiments show that the proposed composite porous structure has better mechanical continuity and 19% lower initial peak stress than the TPMSs basic structure, and has better compressive performance and 48% stronger energy absorption capacity than the lattice structure. Additionally, a mesh fusion optimization strategy is proposed to avoid the stress concentration and improve the structural strength. Highlights: A composite porous structure with stress-driven geodesic Voronoi pores on TPMS is proposed, improving the material utilization ratio. The mechanical continuity of the composite porous structure is improved, compared with TPMS structure and lattice structures. The composite porous structure has better performance on energy absorption ability, compared with TPMS structure and lattice structures. The introduction of geodesic Voronoi based on heat diffusion expedites the generation speed of Voronoi diagrams on surface.