Statistical Fatigue Analysis of the SH-60B Servo Beam Rail Component

摘要

Statistical methods were researched to better understand the effect of the flightloads on the servo beam rail component of the SH-60B helicopter. The extreme value distribution and the Weibull distribution were used to model the distribution of flight loads. Specifically, the flight loads for the symmetric pullout maneuver were studied. Both models successfully represented the data, although more data are required to be fully confident in these representations. Different flight characteristics indicate that various factors such as gross weight, airspeed, and collective position effect the distribution of loads. The model runs indicate a good representation of the individual runs in fatigue life calculations. The damage calculated for the Sikorsky substantiation load run was less conservative than the model run. In addition, the maximum load of the substantiation run was only in the 45th percentile of the load distribution estimated using an extreme value distribution for loads. The damage calculated for the Sikorsky substantiation load run was more conservative than the damage calculated for the individual runs which was reduced as much as 100 times when corrected for mean load.