Low cycle fatigue simulation and fatigue life prediction of multilayer coated surfaces

This paper focuses on the simulation of low cycle fatigue (LCF) failures in highly loaded coated surfaces subjected to mixed rolling–sliding contact in dry conditions. The development of an advanced finite element (FE) model and creation of a unique user-defined subroutine are used to predict subsurface crack initiation in multilayer surfaces. Through the application of shakedown principles and the critical crack plane theory the developed subroutine, running concurrently with the FE solver, is used to predict the location and orientation of the LCF initiation point for a Tungsten Carbon-Carbide (WC-C) coated surface. Furthermore, a detailed physical wear study is presented from tests on a number of WC-C coated samples subjected to dry mixed rolling–sliding contact under high load. Images of the progressive breakdown of the coated surface are presented along with a detailed discussion of the coating failure mechanisms. Comparison of the results from the simulation and physical tests are made and conclusions drawn.