Determination of Subsurface Thermoelastic Contact Stresses in a Half-Plane Using Temperature Dependent Properties

Contact mechanics problem between a rigid punch and a homogenous half-plane is examined considering frictional heat generation. Friction between the sliding rigid punch and the surface of the half-plane leads to a frictional heat which directly flows towards the half-plane material without a loss, and it changes the material's thermoelastic properties. Calculation of subsurface stresses is crucial in the aspect of mechanical design of components since most of failures arise from fatigue and fracture at regions where subsurface stresses reach higher levels. In order to solve the problem, an iterative algorithm is developed based on the finite element method. Steady state subsurface contact stresses are obtained once the frictional heat on the contact surface reaches equilibrium. Subsurface stresses are calculated for different values of punch sliding velocity and coefficient of friction. It is observed that difference between subsurface contact stresses calculated based on temperature dependent and temperature independent properties is remarkable. Higher values of punch velocity and coefficient of friction leads to greater amount of heat generation, and percent difference between stresses reaches significant level especially near the contact surface. The utilization of temperature dependent material properties provides better approximation in assessing fatigue and fracture behavior of machine parts subjected to frictional contact with heat generation.