Evaluation of structural behaviour of a novel compliant prosthetic ankle-foot

Abstract

This paper proposes a new design of a compliant prosthetic ankle-foot. The ankle-foot is made of glass-fiber reinforced plastic (GFRP) as a composite. The finite element analysis is used to evaluate the structural behavior of the ankle-foot, including the deformation, stress, strain energy, and first natural frequency. The heel-strike, midstance, and toe-off of the ankle-foot are analyzed with three different boundary conditions. The results indicated that the highest von Mises stresses is found on the shank at toe-off. The maximum energy strain of 0.304 mJ is recognized at the instep. The obtained values of stress are still much smaller than the yield strength of GFRP. The results also revealed that the prosthetic ankle-foot is becoming more flexible as due to the compliant ankle. At last, the prosthetic ankle-foot was proved as an effective device to support a human body up to 100 N.