Numerical simulation of fatigue crack growth in Ti-Al6-V4 hip implants under different exploitation conditions

Abstract

One of the most important aspects of materials typically used in biomedical engineering is their resistance to various unfavourable exploitation conditions, which greatly impact their work life. In terms of extreme conditions, two major factors include fatigue and corrosion, and a combination of these can significantly decrease the expected life of various implants. The focus of this paper will be on hip implants made of Ti-Al6-4V titanium alloy, a material commonly used in such applications, due to its resistance to corrosion and bio-compatibility. Research shown here was based on experimental testing of said alloy in order to determine its mechanical properties under different working environments, including normal, salty and wet conditions. These properties were then used as input data for Extended Finite Element method (XFEM) numerical simulations of fatigue crack growth in hip implants with various geometries. This was of particular interest since specimens which were kept in salty and wet environment had a slight degradation of yield stress and tensile strength, but an increase in plasticity.