Reliability Model for Failure Dependence Direction of Mechanical Components

In order to determine the dependence direction of correlated failures in the reliability calculation of mechanical structural systems, a reliability variable determination model was established under a linear regression background according to properties of the linear dependent coefficient. Using the Copula regression function, the model was expanded to determine directions of correlated failures in the general asymmetrical structures. To verify its validity, the expanded model was applied to a locomotive axle to determine the correlated failure direction of wear failure and deformation failure of the axle. The calculated Skewness coefficients of wear loss and deformation were 2.362×10-6 and 9.665×10-33 respectively. The results indicate that the wear failure was the dominant mechanism, which is consistent with the actual failure form of the axle. This verifies the effectiveness of the model.