Static analysis of an energy storage and return (ESAR) prosthetic foot

Abstract

In this study, structural analysis of energy storage and return (ESAR) prosthetic foot was carried out by using the finite element method. The basic design of the ESAR prosthetic foot consists of four main components: main plate, S-plate, base plate, and auxiliary body. SOLIDWORKS was used for modeling of ESAR prosthetic foot during the design stage. Furthermore, an ANSYS Workbench 16.2 was used to perform a finite element analysis of ESAR prosthetics foot structure. Static simulation is carried out with a loading force of 750 N representing the amount of force that is supported by the edge of the base-plate component during the push-off phase. In the initial design, the maximum stress that occurs during the static loading is 353.96 MPa, exceeding the yield strength of aluminum 6061 of 276 MPa. Hence, to alleviate the exceedingly high maximum stress, three alternative structural reinforcement types are considered for a design modification. The version of reinforcement yielding the smallest maximum stress was selected in the design modification of ESAR prosthetic foot to be used in the robotic prosthetics ankle. The equivalent stiffness of the final ESAR prosthetic foot design has been calculated to be used in the control system scheme.