Structural reliability sensitivity analysis method based on Lamb wave defect quantification

Abstract

The invention provides a structural reliability sensitivity analysis method based on Lamb wave defect quantification, and the method comprises the steps: building a Lamb wave defect quantification model through a Lamb wave damage detection signal, and building a Lamb wave defect quantification uncertainty model through a maximum likelihood method, constructing a unit defect size performance parameter model by means of a strain energy release rate theory, constructing a unit fatigue crack propagation model by means of a Paris formula, constructing a structural overall dynamics model containinglocal defects by combining a finite element theory, and performing structural reliability prediction; and quantifying the influence of the quantitative uncertainty of the local unit defects in the structure on the structure reliability by adopting a sensitivity analysis method. The influence of uncertainty distribution parameters of all parameters in the Lamb wave defect quantitative model and thefatigue crack propagation model on the overall reliability of the structure is quantified, the uncertainty of reliability evaluation and life prediction results can be reduced conveniently, and the method has high practicability.

Description

technical field [0001] The invention belongs to the technical field of detection, in particular to a structural reliability sensitivity analysis method based on Lamb wave defect quantification. Background technique [0002] Sensitivity analysis is mainly to analyze the impact of the uncertainty of the quantified model input variables on the model output, so that the uncertainty of each input variable can be optimized to reduce the uncertainty of the prediction results. During the service process of the structure, due to fatigue, corrosion, aging and other reasons, the units in the structure will inevitably produce cumulative damage, which will easily lead to structural failure. Therefore, real-time monitoring of the damage in the structure and prediction of the reliability and remaining life of the structure according to the damage can avoid serious consequences caused by the failure of the structure. However, due to the uncertainty in the damage quantitative model and life...

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Problems solved by technology

[0003] Current research mainly focuses on the influence of unit defects on the reliability prediction results of the unit itself. It is difficult to establish a quantitative model between the unit defect size and the overall reliability of the structure. There is still a lack of corresponding quantification of the impact of local unit defects on the overall reliability of the structure. research methods

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