Method for calculating correlation reliability of multi-failure modes of mechanical part

Abstract

The invention discloses a method for calculating a correlation reliability of multi-failure modes of a mechanical part and is applied to the technical field of reliability analysis of mechanical products. The method comprises the steps of representing a correlation between the failure modes by use of a Vine Copula function in consideration of the correlation of the failure modes to establish a multi-dimensional joint probability density function in the multi-failure modes; in consideration of difficulty of the multi-dimensional joint probability density function on the integral, converting each failure mode into mutually independent random responses according to the obtained multi-dimensional joint probability density function in multi-failure modes considering the correlation; and calculating a failure probability of the multi-failure modes based on a simulation method and a saddle point approximation. According to the method, compared with the existing failure probability method of the multi-failure modes, the correlation between the multi-failure modes is quantified and approaches the practical situation of a project.

Description

technical field [0001] The invention belongs to the technical field of reliability analysis of mechanical products, and in particular relates to a reliability evaluation technology under multi-failure mode correlation and complex uncertainty input of mechanical parts. Background technique [0002] Various failure modes may occur in mechanical structures under complex service environments, among which static strength failure, stiffness failure and fatigue failure are the main failure modes. However, in order to simplify the complexity of the design in the actual engineering design process, the reliability issues corresponding to the strength failure and stiffness failure of the mechanical structure under the action of static load and the fatigue failure under the action of dynamic load are considered separately. However, for most mechanical structures, these failure modes are not independent, but have a strong correlation, which is mainly reflected in: (1) The same external l...

AI Technical Summary

Problems solved by technology

However, the reliability evaluation of mechanical structures with multiple failure mode correlations and complex uncertain inputs has yet to be resolved.

[0004] When the random input parameters of mechanical parts are multimodal distribution or more complex distribution, the calculation accuracy and efficiency of traditional reliability methods can no longer meet the engineering needs

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