Experimental and FEM analysis of the material response of porous metals imposed to mechanical loading

Abstract

The mechanical behaviour of cellular structures is governed by their internal architecture. Therefore, it is of interest to incorporate a quantitative description of actual three-dimensional microstructures in the mechanical analysis of materials. In this contribution, an experimental-computational methodology has been developed to facilitate finite element method simulations of complex three-dimensional cellular structures, i.e. to open-cell Ni and Al foams. Two different approaches were examined to visualize the exact three-dimensional (3D) structure of the examined Ni and Al foams, X-ray computed tomography and a serial sectioning image-based process, respectively. In situ micro-tensile tests were carried out in order to determine the foam mechanical properties while scanning electron microscopy was used to monitor the deformation and fracture of the struts. Both experimental results and FEM simulations reveal that the distributions of local stresses and strains depend on size, orientation, and spatial arrangement of the pores.