STRAIN GAUGE VALIDATION OF FINITE ELEMENT ANALYSIS OF A TI6AL4V (ELI) MANDIBULAR IMPLANT PRODUCED THROUGH ADDITIVE MANUFACTURING

Abstract

Medical implants created by Ti6Al4V (ELI) through Additive Manufacturing (AM) processes have a very positive impact on the quality of life of patients who have undergone bone reconstructive surgery. The effectiveness of medical implant design for AM processes would be significantly improved if finite element analysis (FEA) could be established as an accepted design tool. This study is aimed at validating FEA as a tool for predicting the strain distribution in a Ti6Al4V (ELI) medical implant produced through a selective laser melting (SLM) process by comparing the FEA results with strain gauge measurements. The approach followed was to demonstrate the correlation between an FEA model and strain gauge measurements performed on a human mandibular implant. For the design of the mandibular implant the geometrical representation of an adult human mandible obtained from a computerized tomography (CT) scan was used. This CAD model was then submitted to FEA when subjected to typical static mastication load conditions. Through this simulation the distribution of strain in the implant was determined. Using the same CAD model, an implant was manufactured through SLM and strain gauges were mounted on the implant at locations corresponding to the areas of highest strain as determined on the FEA model. The results obtained from both FEA and strain gauge measurements are presented in this paper, and a correlation within an error margin of less than 10 % for most of the gauge was obtained. Requirements for achieving this level of correlation are discussed. It is concluded that FEA is indeed a powerful tool for improving the effectiveness of design for AM of medical implants.