Simulation of a crack emanating from a microvoid in cement of a reconstructed acetabulum

Abstract

In this study, the finite element method is used to analyse the crack behaviour emanating from a microvoid and the effects of the crack-microvoid and crack-crack interactions according to the crack locations in the cement of the reconstructed acetabulum by computing the stress intensity factor (SIF) at the crack tip. We selected one load case corresponding to the stem axis position of 50° which reflects the squatting activity. We show that the failure mode of these cracks (opening and shearing) depends on the orientation of the crack and its size. The crack initiated along the cement thickness propagates essentially in mode I. The initiated crack in the cement (90°) propagates in mode II and the crack inclined with 45° propagates in mixed mode. We also show that the crack propagation kinetics depend on the presence of the microdefects in the propagation crack path. This behaviour leads to the fracture of the cement and the loosening of the prosthesis.