Finite element simulation of nanoindentation tests for cortical bone using a damage plastic model

Abstract

Quality of bone tissue deteriorates with age and disease. Mechanical techniques that evaluate properties of cadaver bone help in understanding mechanisms behind aging and disease and by extension, in the quality assurance of engineered bone tissue like bone grafts. Use of inverse engineering techniques help in interpreting bone properties from experimental data. A damage plastic model that considers damage accumulation during post yield was proposed in order to represent bone in finite element simulations. Finite element simulation of nanoindentation test was carried out using the damage plastic model and perfect plastic model. Comparison of the results of simulation with experimental nanoindentation data concluded that the damage plastic model is a realistic representation of cortical bone. This model was successfully utilized to inverse engineer the experimental nanoindentation data for assessing the Elastic Modulus and Yield Stress of cortical bone. Thus in situ properties of bone were interpreted from the minimally destructive technique.