Optimal design of interfaces in a femoral head surface replacement prosthesis considering nonlinear behaviour

Shape optimization problems applied in the field of biomechanics are presented. Particularly the shape optimization of interfaces separating the bone tissue from the orthopaedic implant are considered. Nonlinear interface behaviour is included in the computational models: a nonlinear elastic model and a damage based model. For the two nonlinear interface constitutive laws an analytical shape sensitivity formulation has been developed. The objective functions included both the effect of the interface stresses and of the interface micromotions. The optimization procedure provided optimal designs, which display better mechanical performance in terms of interface stresses and damage diffusion.