Experimental investigation of the anisotropy of mechanical properties of porous structures designed based on triply periodic minimal surfaces

Abstract

In this research, the anisotropy of mechanical properties of triply periodic minimal porous structures has been investigated. This research studies the effect of anisotropy on the plastic behavior and energy absorption of Schwarz primitive, diamond, and gyroid structures and shows that changing the load orientation and geometry of porous structures can change their mechanical properties and performance under real loading conditions. Twelve samples of Schwarz primitive, diamond and gyroid structures have been designed and these samples have been modeled at angles of 0, 30 and 60 degrees as well as in the direction of the main diameter. The modeling process has been carried out using mathematical functions and scripting in the MATLAB software and the models have been designed in computer-aided design software. Subsequently, these models have been manufactured using the fused deposition modeling additive manufacturing method. The manufactured samples have been subjected to quasi-static compression tests with speed of 1.5 mm/min based on the ASTM D695 standard and their force-displacement data have been extracted. The results of these tests include the analysis of force-displacement diagrams, absorbed energy, stiffness and yield force, which have been used to investigate the plastic behavior and energy absorption capacity of the structures under quasi-static loading. The results showed that the coefficient of variation of energy absorption in the gyroid structure is three times that of the diamond structure, indicating a greater sensitivity of this structure to geometric orientation. However, the gyroid structure oriented along the main diameter has the highest energy absorption and the most suitable conditions for energy absorption among the tested structures. The obtained results can be effective in designing porous structures with optimal mechanical properties for various applications, especially in the fields of structural engineering, energy, and composite materials.