Mechanical structure reliability analyzing method based on coupling of multiple failure mechanisms

Abstract

The invention provides a method for analyzing reliability of a mechanical structure with an effect of coupling multiple failure mechanisms. Simultaneous actions and interaction of the failure mechanisms can be considered, and the reliability, reliable service life and sensitivity of the structure are analyzed. The method mainly comprises five steps: determining a damage equivalence main parameter,and showing the actions of the multiple failure mechanisms by using the same parameter by taking damage equivalence as a basic principle; constructing a damage equivalence physical model, and establishing a damage superposition model or a correction factor model according to difference of the contribution ratio of the failure mechanisms; carrying out parametric simulation, controlling the geometrical shape, material attribute, load and the like of the structure by adjusting parameters, and automatically reconstructing the damage equivalence physical model; analyzing randomness of the failurephysical model, considering parameter randomness, and analyzing the reliability, reliability sensitivity, reliable service life and the like of the structure with the aid of an improved primary reliability method and the like; and correcting a randomness result of the failure physical model by fully using data in a product development and use process on the basis of Bayes model randomness correction so as to improve analysis precision.

Description

technical field [0001] The invention provides a reliability analysis method for a mechanical structure with multi-fault mechanism coupling effects, and belongs to the fields of mechanical design and structural reliability design. Background technique [0002] The faults of mechanical structures are mostly wear-and-tear faults, and damage is a physical process used to describe the performance degradation of structures or materials under load and lead to damage. Many structural parts in engineering, such as some aircraft components, generally suffer from fatigue damage. Taking the engine turbine disk as an example, the engine works continuously for several hours after starting, then stops for several hours, and then starts again, which is a load cycle. However, the working environment of the vortex is high in temperature, accompanied by creep. Therefore, when studying their life, it is necessary to consider not only the destructive effect of fatigue, but also the coupling ef...

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Problems solved by technology

[0003] At present, a relatively large amount of research work has been carried out in the machinery industry on the reliability analysis of the single fault mechanism of the structure, and the reliability research on the multi-fault mechanism is still in its infancy.

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