Shafts Reliability Assessment in Accordance with Criteria of Fatigue Strength Under Random Load Conditions

摘要

The paper considers an improved method of shaft strength reliability calculation based on random values and nonparametric statistics computer simulation methods. The probability of shaft failure-free operation under random load condition is estimated by the fatigue strength resistance criterion. In this case, the safety factor is defined by a sample obtained using nonparametric generators. The paper considers four standard load conditions described by normal, equally, gamma-, and beta-distribution, and also random distribution defined by the user. A probability density function of the safety factor is recovered by the Parzen-Rosenblatt method. All algorithms are realized in Mathcad processor software. The authors carried out computer simulation which showed the difference in the shaft failure probability at different load condition varying from 0.702 to 13.936%. The proposed method allows one not only taking into account actual laws of external load distribution, but also recovering a factual function of safety factor density distribution as well as a failure-free operation probability in accordance with it.