Frictional heating in contact mechanics – a methodology to deal with high temperature gradients

In this paper a methodology for the numerical solution of frictional heating problems is presented. The penetration process of a steel nail into a steel support is used as a reference case for the axisymmetric formula- tion. The problem is characterized by a big amount of heat generated by frictional dissipation. Such thermal heating plays an important role in the anchoring of the nail and in the pull-out resistance. Due to the short time transient the heat is stored inside a very thin layer around the contact surfaces. In order to minimize the computational effort a local lagrangian thermal discretisation is used in the heat affected zone. Since a weakly-coupled solution is provided, thermal and mechanical discretisations around contact surfaces are different and only geometrically linked. The adopted weakly-coupled solution solves separately the thermal and the mechanical fields, following a staggered procedure.