On the flash temperature in sliding contacts

TL;DR

This paper develops an analytical theory for flash temperature in sliding contacts with multiscale rough surfaces, revealing limitations of classical models and providing more accurate temperature estimates.

Contribution

It introduces a new analytical approach that accounts for multiscale roughness in predicting flash temperature during sliding contact.

Findings

Classical theories significantly underestimate flash temperature for multiscale rough surfaces.

Numerical examples for rubber on concrete and granite on granite illustrate the theory.

The new model extends stress correlation methods to include temperature effects.

Abstract

The temperature increase in the contact regions between solids in sliding contact can easily reach several hundred Kelvin and thereby dramatically affect friction and wear. The classical theories by Jaeger, Archard, and Greenwood, commonly used to estimate flash temperature, ignore the multiscale nature of real surfaces and instead approximate the frictional heat sources with circular or square shapes. Here, we present an analytical theory for the flash temperature valid for randomly rough surfaces with roughness across arbitrarily many decades in length scale. The theory extends established methods for stress correlation functions and peak stresses to temperature. Numerical results for rubber sliding on concrete, and granite on granite, are presented as illustrations. We show that classical theories for flash temperature fail severely for surfaces with multiscale roughness.