Simulation of compression behavior of porous structure based on different space-filling unit cells under quasi-static loading

Abstract

Porous materials have remarkable mechanical properties. With the development of methods to produce cellular structures such as additive manufacturing, the fabrication of metal foams with the desired geometry and properties has expanded greatly. Despite the existence of more than a 100 types of cellular structures, the behavior of many of them remains unknown. Therefore, the objective of this work is to get more insight into the influence of cell geometries on the compression characteristics of porous materials. Moreover, the influence of density on typical compressive properties of porous materials such as elastic modulus, yield stress, plateau stress, and energy absorption are studied in the present study. To this end, three different values of foam density for five-unit cell configurations including alternated cantitruncated cubic honeycomb (ACCH), cantellated cubic honeycomb (CCH), rectified cubic honeycomb (RCH), Kelvin (K), and Weaire-Phelan (WP) are considered. The results imply that, overall behavior of porous structures highly depends on individual cell deformation. Stress localization on the macro scale is a consequence of failure at the cell level. To validate numerical results, several experimental tests are carried out. Various unit cell configurations show a different level of influence on typical compressive properties. Therefore, the structures are divided into two groups in terms of elastic modulus: those that are stiff (ACCH, CCH, and RCH unit cell) and those that are compliant (K and WP unit cell).