Reverse engineering and finite element analysis of Ti-6Al-4V orthopaedic hip implants

The goal of the research presented is to combine reverse engineering methodologies with a numerical approach to analyse the structural integrity of artificial hip implants made of Ti-6Al-4V alloy subjected to different types of loads. In this way, numerical models validate the adopted methodology for obtaining implant geometry using 3D scanning, while also providing valuable insight into the behaviour of hip implants under different static loading cases. Since 3D scanning is proven as efficient and reliable for obtaining accurate geometry of various types of implants, it is applied in this research. Following a detailed development of a hip implant model geometry, involving 3D scanning and refining the obtained point cloud to a level that would realistically represent the actual hip implant, numerical models are made based on the obtained geometry. Results of these simulations using the finite element method in ANSYS® software have provided realistic values of stresses in most critical areas of the hip implant. The precise value of load that would produce plastic strain on the implant is also determined and is used as the limit criterion for selecting load cases for further analysis. This analysis would involve the assessment of fatigue life of hip implants with the same geometry and the same material while assuming the presence of a crack in the most critical area.