Fretting fatigue and wear in bolted connections: A multi-level formulation for the computation of local contact stresses

The bolted connection between the wheel and the hub of off-highway vehicles is investigated, with particular interest in local contact interactions and the effects they have on wear and fatigue of the joint. Although the importance of contact related damage, in the form of fretting fatigue and wear, on the life of joints is well documented, sufficient analysis of the interactions between the mating surfaces is usually neglected due to the computational difficulties that arise when contact is considered thoroughly. In order to overcome these limitations, a two-dimensional model of the bolted connection is introduced that enables the characterisation of the macroscopic behaviour of the joint and leads to a direct prediction of the contact stresses at the interface between the mating bodies. An indirect boundary element technique, which is based on elementary complex potentials, is developed to compute the stress field within the joint members. The work presented in this paper enables a better understanding of the mechanics of these connections and may prove useful for the assessment of different failure mechanisms in bolted joints.