Design and simulation of prosthetic feet manufactured by Continuous Filament Fabrication

Commercially available prosthetic feet range from cost-effective options like the solid ankle cushioned heel foot for low ambulation potential patients to Energy Storage and Return (ESR) feet for high ambulation potential patients. Traditional ESR feet, typically made from laminated composites, are expensive and difficult to customize. Modern additive manufacturing technologies, like continuous filament fabrication, could offer a cheaper and more versatile solution. This study aims to use Finite Element (FE) simulations to enhance the design process of ESR feet produced using this technology. Firstly, the accuracy of modeling such ESR feet using beam finite elements was assessed with reference to plane stress finite elements. The assessment showed that beam finite elements have limited accuracy for simulating complex geometries such as composite sandwich-structured ESR feet. Secondly, topology optimization was used based on plane stress FE modeling to refine an ESR foot design. This allowed an optimized usage of continuous fiber reinforcements.