The Modeling and Effect of FEM on Prosthetic limb

Abstract

In this study, three dimensional Finite Element (FE) modeling of prosthetic lower limb was performed. A modified three dimensional finite element model of socket was developed in workbench of ANSYS 14.0 to find out the stress distribution and deformation pattern under functionally appropriate loading condition during normal gait cycle. This work tried to improve the deflection of the loading of Socket, foot, and pylon shank. The best designs results of the prosthetic above knee socket are (94.64%).In addition, a simplified stiffener has been added to optimize a moment of inertia of this main part thereby the deflection will be better, for this purpose a case study has been considered according to international standard for the Socket specification that investigated to illustrate the goal of this work . Moreover, the adopted design was selected carefully in order to match high strength and minimum weight criteria. Two types of FE analyses were performed; static analysis at standing position and dynamic analysis at jumping condition. The obtained results showed that the dynamic impact load is the most dominant since both materials were capable to stand with static load with minor Von Mises stresses acting on the pin connections. On the other hand, high Von Mises stresses were developed in the case of dynamic impact load which reached 90.19 MPa model. The results show that using stabilized method enables us to get stable and accurate numerical approximations consistent with the physical configuration of the problem over rough mesh by using ANSYS Workbench 14.0, AutoCAD and COMSOL 5.2. A high-density polyethylene (HDPE) was used for pylon.