Mechanical Behavior of Hybrid Lattices Composed of Elastic and Elastoplastic Struts

Abstract

The mechanical behavior of cellular solids has been extensively studied in the literature. Nevertheless, possible structural effects of inhomogeneities in the form of elastoplastic struts have not yet been investigated. We present a numerical analysis of the tensile behavior of triangular, diamond, and hexagonal hybrid lattices composed of both elastic and elastoplastic struts. In particular, some struts are assumed to behave as strain-hardening elastoplastic beams while others are assumed to behave as a linear elastic material. It is found that both the stiffness and the strength of the lattices decrease with increasing percentage of elastoplastic struts. Furthermore, the presence of elastoplastic struts markedly alters fracture toughness. The effect of relative density on the tensile behavior of hybrid lattices is also investigated. It is concluded that in addition to the microstructure of cellular solids, the constitutive behavior of individual struts significantly affects their macroscopic mechanical response. Thus, the spatial distribution of struts with different material properties can be considered a novel approach in the design of cellular solids with desired properties.