Keywords: freight wagon, tread braking, temperature-dependent friction, thermo-mechanical coupling, long downhill braking, hybrid numerical modelling.

Under long-duration braking conditions, particularly for freight trains on extended steep gradients, substantial heat accumulation can occur in wheel treads, resulting in complex thermo-mechanical responses and potential damage. A hybrid computational framework coupling MATLAB and ANSYS APDL is developed to iteratively update friction coefficients based on experimentally calibrated evolution laws. It enables the calculation of frictional power input, transient temperature fields, and thermal stresses while maintaining computational efficiency. Parametric analyses under varying gradient magnitudes and slope lengths are conducted to systematically compare constant and variable friction assumptions. The results show that incorporating time- and temperature-dependent friction introduces an intrinsic negative feedback mechanism into the thermo-mechanical system. It reduces peak tread temperature and thermal stress by up to 25–30% under severe braking conditions. Unlike the monotonic growth predicted with constant friction, the variable-friction model produces self-limiting “rise–fall” or “rise–stabilization” response patterns. It also promotes earlier attainment of dynamic thermal equilibrium. This study presents an advanced tribology-informed hybrid modeling framework for coupled thermo-mechanical analysis in sustained tread braking, enhancing physical fidelity while maintaining computational efficiency, with potential applicability to sliding contact systems under prolonged thermal exposure.

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