On Modeling Bonds in Fused, Porous Networks: 3D Simulations of Fibrous–Particulate Joints

Abstract

The deformation and failure of fused, porous networks are key concerns in microscale power sources and open trusses for structural applications. We have found that the behavior of the connection points in these open networks is the most critical determinant of materials response. For many manufacturable material geometries, both stiffness and strength are largely controlled by these interparticle or interelement bonds, rather than by the response of the longer aspect ratio sections. Classic work in sintered materials is of limited applicability in this context, since formation of multiphase porous networks often involves volume-conserving interconnects, or fused sections created by additional material, rather than via (heated) compaction of particles or elements. Here we expand on previous work in 2D network behavior (reviewed in [1]) by focusing on the geometry and response of 3D interconnects between cylindrical elements. We present computational results for deformation of 3D interconnects in a large class of stochastic fibrous and particulate structures. Further, we suggest methodologies for adapting tractable 2D simulations to account for the known 3D stress-enhancing effects. We conclude with some comments on limiting strengths and toughnesses in these materials, and suggest divisions for classifications of these porous network bonds.