Collapse models of aluminum foam sandwiches under static three-point bending based on 3D geometrical reconstruction

摘要

Metal foams are a relatively new class of materials exhibiting well physical and mechanical property. A modeling algorithm, which can accurately describe the detailed structure of cellular materials, is useful to discuss the relationship between mechanical properties and structure of cellular materials based on the analysis methods of finite element. In this paper, a novel modeling method is proposed by MATLAB image processing and synchrotron X-ray computed tomography (μCT) scanning. Accordingly, the finite element model (FEM) of aluminum foam, which is the core of aluminum foam sandwiches (AFS), is established by the novel method. The failure mode of AFS is discussed by ABAQUS/Explicit. The ductile damage initiation criterion, MSFLD damage initiation criterion and shear damage initiation criterion are used to describe the damage initiation, and the linear damage evolution law is used in the calculation process. Unlike Michailidis's 3D reconstruction method and Jeon's 3D reconstruction model, the novel method has a smaller difference in structure size between the geometric model and the real model, and higher efficient. According to statistics, the porosity is 49.2%. The equivalent diameter is distributed mainly in interval (1, 3). Damage initiation criterion and linear damage evolution law can describe the AFS collapse mode of core shear. Critical loads of FEM calculation are agreed with theoretical modeling, which proves the 3D reconstruction algorithm of foam core is correct and applicable. The critical load is decreased with span distance increasing.