Compression failure of porous ceramics: A computational study about the effect of volume fraction on damage evolution and failure

Abstract

The work describes a numerical method to study the nature of compressive failure of porous ceramics in relation to its volume fraction. The microstructure of an alumina-based foam material manufactured by mechanical stirring of a slurry is studied here. A finite element-based compressive failure simulation of a real microstructure obtained from microtomography (micro-CT) scans is conducted. A recently developed microstructure reconstruction algorithm is utilized to generate artificial microstructures statistically equivalent to the real one obtained from micro-CT. The accuracy of the reconstruction procedure is established by comparing the simulated compression behavior of the reconstructed microstructure with that of the real one along with the experimentally measured results. The effect of sample size on the simulated compression behavior is studied by computing compression stress-strain behavior for varying sizes of the reconstructed microstructures. Further, artificial microstructures of the porous ceramic with different volume fractions are reconstructed along with computing compression stress-strain behavior to establish relationship between ceramic content (volume fraction) and compressive strength of this material. The nature of the compressive failure for microstructures with different volume fractions is studied and the results are compared with the analytical models and the experimental observations available in the literature.