Crack simulation of nano-bioceramic composite microstructures with cohesive failure law: effects of sintering, loads and time.

Abstract

Crack behaviour of zirconia toughened alumina (ZTA) microstructures are simulated with a two-dimensional finite element simulation. Finite element models are developed using actual microstructure images of zirconia toughened alumina and a bilinear cohesive zone law. Simulation conditions are similar to those found at frictional contact between a femoral head and an acetabular cup of hip prosthesis. Effects of microstructures and contact stresses are investigated in terms of crack generation. Moreover, fatigue behaviour of a microstructure is determined by performing simulations under cyclic loading conditions. It is identified that total crack length observed in a microstructure increases with increasing the magnitude of applied contact stress. Cyclic simulation results show that progressive crack growth occurs with respect to number of fatigue cycles. In addition, it is demonstrated that zirconia grains resist crack growth in microstructures.