Finite element modelling of functionally graded elastomers for the application of diabetic footwear

Abstract

Diabetic foot ulcers are major components of diabetic foot. Uncontrolled sugar levels can lead to this complication. During this complication, skin begins to peel off thus exposing the layers underneath. Big toes, heels and pads of the feet are the common places this could occur and can affect deep to the bones. In this paper, the complexities due to foot ulcers are analyzed. The treatments include, removing pressure from the wound in order to prevent pain. The aim of this paper is to provide a footwear made of functionally graded polyurethane in order to impart comfort for the patient. The concept of functionally graded polyurethane(FGPU) is to make a composite material by varying the properties from one material to another with a specific gradient. Uniaxial compression test is performed on five different densities of polyurethane foam and respective stress strain curves are obtained. The polymers are then stacked one above the other based on hardness starting from high to low. The behavior of this material is studied by applying appropriate hyperfoam material model. 3D model of the sole of the footwear was created in ANSYS and proper material properties are assigned to respective layers. According to patient’s regular activity, FEM analysis is performed. The distribution of stresses vs time due to weight of the person are observed and further optimized if needed.