Study on the Topological Morphology and Mechanical Properties of Variable-Amplitude TPMS structures

TPMS structures possess immense potential in terms of lightweight and multifunctional applications. However, previous studies have predominantly focused on aspects such as wall thickness, unit cell size, periodicity, and level set values. The impact of amplitude factors on the topological shape and mechanical properties of TPMS has not been fully elucidated. Here, primitive (P), gyroid (G), and diamond (D) structures were initially examined to explore the effects of amplitude factors on the topological shape and relative density of TPMS structures. The mechanical properties and energy absorption capability of the variable amplitude structures were investigated, with emphasis on a gyroid structure, using both experiments and numerical simulations. It was found that the amplitude does not alter the deformation pattern of the structure. However, the mechanical properties of the structure can be regulated over a relatively large range. Specifically, the elastic modulus and yield strength at an amplitude of 1.6 were observed to be approximately 1.5 times those at an amplitude of 0.4, and the plateau stress was approximately 1.33 times that of 0.4. Additionally, with increasing amplitude factor, there was a slight decrease in the densification strain of the structure but a significant increase in its energy absorption capability. Such findings offer a novel means by which the mechanical properties of TPMS structures can be modulated, providing new opportunities for the development of tissue scaffolds or energy-absorbing devices.