Assessment of frictional performance of custom designed shoe treads using a computational fluid dynamics-based model: Implications on slips and falls

Abstract

Slips and falls often result in non-fatal injuries due to reduced friction between footwear and flooring. A combined computational framework utilizing finite element analysis (FEA), computational fluid dynamics (CFD) and, alongside experimental tribological testing, to evaluate the performance of footwear outsoles was implemented. Twelve custom-designed outsoles were tested, where fluid pressure and mass flow rates were measured through CFD, and FEA was employed to analyze outsole deformation under normal loading conditions, incorporating the material properties of hyperelastic Neo-Hookean. A custom slip testing device assessed dry and wet friction. The results revealed that the square tread pattern exhibited the highest mass flow rates and decreased fluid pressures, followed by the vertical pattern. Increasing tread gaps correlated strongly (R² = 0.92) with high wet friction. Horizontal patterns showed lower mass flow rates and higher fluid pressure. This model provides insights for improving outsole design and shoe performance to enhance safety.