Axisymmetric finite element analysis of hip replacements possessing an elastomeric layer: the effects of clearance and Poisson's ratio.

A finite element analysis has been performed for a hip replacement incorporating an elastomeric surface layer. The effects of assuming the elastomer as incompressible have been examined for imposed loads, by comparing the incompressible solution to that using accurately measured values for Poisson's ratio, and while deflections were found to be significantly different, the changes in maximum pressure in the contact, maximum shear stress, contact angle and angular position to maximum shear stress were all small (less than 10 per cent). Comparisons have also been made between the finite element results for ABAQUS and an asymptotic solution, and it was found to be important to use the numerical model particularly at small values of clearance.