Fretting Fatigue and Wear of Spline Couplings: From Laboratory Testing to Industrial Application through Computational Modelling

One of the major challenges for fretting fatigue design is the bridging of the gap between laboratory tests, including associated theoretical and computer models, typically constrained to simplified loading conditions, and the need for real-life solutions, which relate more directly to in-situ loading, environmental and other relevant conditions, including geometrical constraints of target machine or structural components. This chapter describes experiences and challenges relating to the application of computational modelling to the design of simple but representative tests for fretting fatigue and wear of complex aeroengine spline couplings. It is proposed that the key step forward for fretting is to recognise, on the one hand, the importance of spatial and temporal field distriibutions of key multiaxial surface and sub-surface parameters, rather than try to reduce down to a single parameter or set of simple variables, such as normal load, coefficient of friction and stroke, and, on the other hand, to develop experimental tests which represent these spatial-temporal distributions. This is entirely feasible using modern nonlinear computational techniques, in combination with experimental and theoretical advances in fretting.