Whether zhuan 8AG type bogie can achieve the requirement of speed increasing, which have become an important question need to face and research for the railway sectors. The residual life of zhuan 8AG side frame is studied by interior fatigue test that equivalent to the actual running conditions. The interior fatigue test data was processed by Weibull distribution with 3 parameters. The point estimation and the interval estimation of the safe life were given. The fitting result indicate that, the test date conform the Weibull distribution very well. Using generalized P-S-N formula and correctional two dimensional Miner’s rule derivate the residual running mileage prediction formula of zhuan 8AG side frame based on the interior test and the actual line test. The point estimation and interval estimation of residual life are computed under certain reliability and confidence. The estimation results show that, under 95% confidence and 99.9% reliability, the zhuan 8AG side frame has 10.6 years residual life at least. Thus, its’ prospect of applications by increasing speed is optimistic. As a result of some difference about forces on side frame between internal test and actual operation, high incidence area of crack in test is different from in reality. In this fatigue test, breakages are all the C position of side frame. However, the highest probability of crack occurred position in the top surface of pedestal, which total crack numbers accounted for 50% of total crack numbers on side frame in actual running. The paper recommends that the results between internal fatigue and actual operating should be analyzed comparatively, so as to simulate the actual working conditions more realistic.
Interval Estimation for Extreme Value Parameter with Censored Data
