Department of Engineering Mechanics, Dalian University of Technology, Dalian, China.
DUT-BSU Joint Institute, Dalian University of Technology, Dalian, China.
Proc Inst Mech Eng H. 2022 Aug;236(8):1157-1168. doi: 10.1177/09544119221102704. Epub 2022 Jun 1.
In recent years, the triply periodic minimal surface (TPMS)-based scaffolds have been served as one of the crucial types of structures for biological replacements, the energy absorber, etc. Meanwhile, the development of additive manufacturing (AM) has facilitated the production of TPMS scaffolds with complex microstructures. However, the design maps of TPMS scaffolds, especially considering the AM constraints, remain unclear, which has hindered the design and application of TPMS scaffolds. The aims of the present study were to develop an efficient computational modeling framework for investigating the design maps of TPMS scaffolds simultaneously considering the AM constraints, the biological requirements, and the structural anisotropy. To demonstrate the computational framework, five widely-used topologies of the TPMS-based scaffolds (i.e. the Diamond, the Gyroid, the Fischer-Koch S, the F-RD, and the Schwarz P) were used, whose design maps for the surface-to-volume ratio and the effective elastic modulus were also investigated. The results showed that as the porosities increase, the design ranges of the surface-to-volume ratios decreases for all the structures. Compared with the effect of the constraint for the pore size, the minimal structural thickness for AM constraint has a greater effect on the surface-to-volume ratio. Regarding the elastic modulus, in the region of low porosity (approximately 0.5-0.7), the range for the effective elastic modulus of Schwarz P is the widest (approximately 2.24-32.6 GPa), but the Gyroid can achieve both high porosity and low effective elastic modulus (e.g. 0.61 GPa at the porosity of 0.90). These results and the method developed in the present study provided important basis and guidance for the design and application of the TPMS-based porous structures.
近年来，基于三重周期性极小曲面（TPMS）的支架已成为生物替代物、能量吸收器等的关键结构类型之一。同时，增材制造（AM）的发展促进了具有复杂微观结构的 TPMS 支架的生产。然而，TPMS 支架的设计图，特别是考虑到 AM 约束，仍然不清楚，这阻碍了 TPMS 支架的设计和应用。本研究的目的是开发一种有效的计算建模框架，用于同时考虑 AM 约束、生物要求和结构各向异性来研究 TPMS 支架的设计图。为了演示计算框架，使用了五种广泛使用的基于 TPMS 的支架拓扑结构（即 Diamond、Gyroid、Fischer-Koch S、F-RD 和 Schwarz P），还研究了它们的比表面积和有效弹性模量的设计图。结果表明，随着孔隙率的增加，所有结构的比表面积设计范围都减小。与孔径约束的影响相比，AM 约束的最小结构厚度对比表面积的影响更大。关于弹性模量，在低孔隙率（约 0.5-0.7）区域，Schwarz P 的有效弹性模量范围最宽（约 2.24-32.6 GPa），但 Gyroid 可以实现高孔隙率和低有效弹性模量（例如，孔隙率为 0.90 时为 0.61 GPa）。这些结果和本研究中开发的方法为基于 TPMS 的多孔结构的设计和应用提供了重要的基础和指导。
