Master Thesis • Adidas Collaboration
Developed a tribology-driven framework to investigate traction, slip initiation, and grip-to-slip transitions in elite running footwear during toe-off. The project combined analytical modelling, experimental testing, and surface interaction analysis to understand how PEBA foam properties, thickness, and ground texture influence running traction under realistic loading conditions.
Industry Partner
University
Specialization
Focus Areas
Engineering Problem
Modern performance footwear is heavily optimized for cushioning and energy return, yet the mechanisms governing slip initiation during high-speed running remain insufficiently understood.
Existing studies largely focus on global friction measurements without linking local material deformation, contact evolution, surface roughness, and tangential loading behavior. This project addressed that gap by treating the shoe–ground interaction as a complete tribological system during the toe-off phase of running.
Research Framework
Used Hayes’ elastic layer indentation model to determine thickness-dependent stiffness behavior of PEBA foams used in performance footwear midsoles and outsoles.
Applied Westergaard-based contact formulations to study contact evolution between compliant foam materials and textured asphalt-inspired surface geometries.
Implemented Adams’ partial-slip framework to investigate transitions between grip, partial slip, and full sliding during toe-off propulsion.
Experimental Investigation
Conducted controlled normal and tangential loading experiments to investigate traction behavior across multiple PEBA foam thicknesses and asphalt-inspired surface textures.
High-resolution textured surfaces were replicated to study contact conformity, pressure distribution, and frictional transitions under realistic toe-off loading conditions.
Key Findings
Thinner and stiffer PEBA foams delayed slip initiation and sustained higher tangential loads before complete sliding occurred.
Smoother surfaces produced significantly higher traction levels, while rougher textures altered conformity and interfacial behavior.
More compliant foams increased real contact area but promoted earlier microslip growth under rising tangential loading.
The resulting framework provides a basis for integrating traction-aware criteria into simulation-driven footwear design workflows.
Product Development Relevance
Strategic stiffness gradients can balance cushioning and traction performance.
Outsole behavior can be optimized based on running surface roughness.
Foam thickness distribution can improve traction in high slip-risk zones.
Predictive modelling enables faster simulation-driven product development.
Outcome
This work established an initial physics-informed framework capable of linking material response, surface interaction, and frictional transitions during running toe-off. The project provides a foundation for future traction-aware footwear design, predictive simulation workflows, and performance-focused product development.