Shrink-fitting is a commonly used process to tightfit mating components such as axles and wheels or sleeves. An important range of applications exists in the railway and maritime industries. Such assemblies are submitted to complex multiaxial fatigue loadings including rotatory bending, compression and torsion. Moreover, differential deformations between the two parts can induce local fretting damages, leading to wear or crack nucleation.

The aim of this study is to describe the impact of interference value on fretting-fatigue behavior and thus on lifetime. No consensus exists in scientific literature concerning this problem. The modification of interference value has a direct impact on contact pressure, and therefore also on local stresses and on sliding amplitude, which are driving factors of fretting solicitations. Impact on the lifetime seems however to be heavily dependent on the range of induced contact pressure, which is in the studied application very low given the large size of the contact. Coupled experimental and numerical studies will be carried out.

Experimental studies will focus on a simplified loading case, i.e. rotary bending, using two specifically designed test benches. The test specimen is a steel shaft with shrink fitted bronze sleeve, which is a scale representation of a maritime drive shaft. Tests will be carried out on an extended range of interference values to obtain fretting-fatigue S-N curves. Damage characterization will focus on fretting wear debris and cracks. The third body layer, which is thought to control crack nucleation, will be precisely quantified using a new disassembly-free measurement protocol.

FEA modeling will be carried out in parallel, with the aim of improving our understanding of the phenomenon and developing a life prediction model. Interference fitting and bending will be considered, as well as friction at the interface, to obtain local contact data such as slip and surface shear. Wear will also be considered to ensure correct modelling of the phenomenon. Multiples tribological and multiaxial fatigue criteria will be implemented as post-treatment to quantify fretting-fatigue damage.