The influence of void morphology and loading conditions on deformation and failure of porous polymers: A combined finite-element and analysis of variance study

This paper presents a combined finite-element and analysis of variance study of polymeric materials containing spherical and ellipsoidal voids. The approach adopted simulates an infinite medium of the material containing an array of voids, using three dimensional finite element analysis. A D-optimal design procedure is used to combine five normalized variables: the stress triaxiality, the ellipsoid ratio, the initial void volume fraction, the void arrangement (number of voids), and the loading angle. A ductile epoxy resin is chosen as reference material and the failure criterion considered is the plasticization of the ligament between two adjacent cells. Results are provided for the normalized equivalent stress and strain at failure, and for the void growth rate. The influence of the variables on the outputs is estimated showing that the response is influenced mainly by stress triaxiality, void volume fraction and void arrangement, in that order.