Numerical and Experimental Investigation of Performance of Styrene Butadiene Rubber, Polyurethane, and Polyvinyl Chloride in Outsoles Fabrication

Shoes are used in daily activities to protect the human foot against applied forces from the ground. One of the most important parts of shoes which absorb the incoming forces is the outsole. The aim of the present research is to investigate the efficiency of three different materials in fabricating outsoles. Outsoles made of styrene butadiene rubber (SBR), polyurethane (PU), and polyvinyl chloride (PVC) were fabricated with the same geometry and without shoe treads. Then, they were tested by the PEDAR system in order to determine the plantar pressure exerted by each outsole, and they were also tested in terms of fatigue, hardness, and uniaxial compression tests, and after the modeling they were analyzed by finite element method (FEM) software. In static and dynamic states, the outsole made of PVC, SBR, and PU reduces the pressure by 44%, 65%, and 59%, respectively on average compared to barefoot posture. SBR in stress (in static and dynamic states) and strain (in static and dynamic states) have 39.06% and 98.75% better performance on average respectively compared to PVC. In addition, SBR outperformed PU in stress (in static and dynamic states) and strain (in static and dynamic states) by 3.45% and 8.5% respectively. To fabricate outsoles, multilayer outsoles should be used in order to concurrently benefit from the positive characteristics of several materials.