Metal structure fatigue reliability analyzing and optimizing design method based on damage mechanics

Abstract

The invention discloses a metal structure fatigue reliability analyzing and optimizing design method based on damage mechanics. The method includes the steps of establishing a parameterized geometric and finite element model according to the key metal structure prone to fatigue through the uncertainty between the interval vector metric structure and material and the damage parameters, and a fatigue life interval range is calculated through the combination of an interval finite element and damage mechanics finite element analysis method; the fatigue reliability analysis of the structure is further achieved through a non-probability interval interference theory; finally, the complete optimization iteration process is achieved with the structure size as the design variable, the reliability degree as the constraint condition and the structure weight as the target function through a global optimization algorithm, and the optimal design variable result found through an output algorithm serves as the final structure optimizing design scheme. By means of the method, the sensitivity of the scheme itself to the design parameters is overcome, the aims of being smallest in weight and making fatigue reliability meet requirements can be achieved under the condition that the structure meets bearing conditions, and thus the design scheme is more economical and reasonable.

Description

Technical field [0001] The invention relates to the field of fatigue fracture and damage mechanics, in particular to a method for fatigue reliability analysis and optimization design of a metal structure based on damage mechanics. The invention is a combination of finite element based on damage mechanics and non-probability interval finite element considering uncertainty Under the fatigue life reliability analysis and optimization design. The invention can provide references for the anti-fatigue design of engineering structures. Background technique [0002] Among the various failure modes of the structure, fatigue is one of the most important causes of structural failure and the most important factor to be considered in structural reliability tests. In many cases, fatigue damage can bring disastrous consequences to people. For example, in 1952, the first jet-type Comet passenger plane was put into service after more than 300 hours of test flight. It crashed and fell into the M...

AI Technical Summary

Problems solved by technology

However, in the calculation process, various factors affecting fatigue performance are not considered, such as the fluctuation of load level, structural size effect, surface finish, surface treatment process, temperature and hot and humid environment, and stress concentration, etc.

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