Hysteretic Damping Characteristics of Ultra-High Molecular Weight Polyethylene Used in Hip Arthroplasties

Abstract

This paper presents a theoretical model and experimental results to determine the hysteretic damping coefficient and the energy losses from the indentation process. The characterization of the ultra-high molecular weight polyethylene in terms of hysteretic damping has an important role in the evaluation of the reliability of the hip arthroplasties subject to vibrations and movement. This is done experimentally with the indentation technique. Following the indentation tests, it is observed that for this material creep is present during the unloading stage. In this study two types of ultra-high molecular weight polyethylene (UHMWPE): nonirradiated (conventional) CPE and gamma-irradiated (cross-linked) XPE were analysed. The hysteretic damping coefficient help in the evaluation of energy losses for the visco-elasto-plastic deformations of the material. The hysteretic damping coefficient can be considered an essential material parameter in assessing the state of stress and deformation of the material. This study shows the comparison between the two materials and the effect that irradiation has on its damping properties.