Modelling of cracking of the ceramic foam specimen with a central notch under the tensile load

Abstract

In this contribution, open cell ceramic foam structures composed of regular/irregular shape cells and containing a macroscopic central notch/crack were investigated in terms of their cracking upon the tensile loading and their strength was predicted using the FE simulations. The developed model of the real ceramic foam specimen containing a central notch/crack was subjected to a tension, resulting in a failure beginning at the tip of the notch. The work discusses an approach how to predict the critical failure load and also the crack path in the foam structure. Various cell irregularity and size of the macroscopic notch was considered in the investigations. Predictions of the foam structure cracking were performed using the beam element based FE model having characteristics of the real foam structure and by utilization of the stress criterion which considers failure of particular struts, when the maximum stress on them reaches the tensile strength of the ceramic material. Outputs from simulations were compared with available experimental observations and with an estimation of the critical failure load calculated using the developed analytical model.