Because fretting fatigue with wear is a nonlinear problem, the entire stress-strain history for a simulation cycle is required for the damage calculation. Wear is continuously scaled during a simulation cycle (auts) or at the end of a cycle, so each simulation cycle corresponds to a number of physical cycles. The damage accrued over a simulation cycle should be mapped over the number of physical cycles (repeat count) using a cumulative damage law for the known number of repeats of the simulation cycle. The scaled time is tabulated in the .cnd file. The repeat counts are calculated by comparing the time period of the simulation and physical cycles as shown in Table 64.1: Calculating repeat counts for each simulation cycle F_y = - 208.4N/mm, auto wear scaling (auts).

The physical time in the table is obtained from the corresponding contact database file (.cnd file). The repeat count of each simulation cycle for the five different loading conditions is calculated. The result (.rst) file and this table are inputs for the fretting fatigue damage analysis.