Anisotropic damage identification method for composite material laminated structure

Abstract

The invention discloses an anisotropic damage identification method for a composite material laminated structure. The method comprises the steps of: arranging piezoelectric and strain sensors for key parts of the structure; using a multi-channel excitation and sensing channel composed of piezoelectric sensors for collecting damage scattering signals, and calculating track curves corresponding to damage boundary points at different positions; on the basis of the obtained track curve set, estimating a damage boundary according to a curve circumscribed relation so as to screen out suspicious damage units, and establishing a damage parameter set; predicting a current damage state based on a damage evolution criterion according to a load applying process, and obtaining an initial value of a damage parameter; and finally, constructing an optimization model for damage parameter quantification, and performing damage degree quantification based on the obtained damage parameter initial value and a sequential quadratic programming method. According to the method, a strategy combining forward analysis and reverse optimization is adopted, accurate quantitative identification of anisotropic damage of the composite material laminated structure is achieved, and the method has the advantages of being high in precision, high in innovativeness and good in practical prospect.

Description

technical field [0001] The invention relates to a method for identifying anisotropic damage of a composite material laminated structure, in particular to identifying the number of damages under anisotropic damage based on the measured Lamb wave signal and strain signal, combined with the results of forward damage evolution analysis, and oriented to the evaluation of the residual strength of the structure. More damage parameters provide direct and reliable model input for real-time structural safety assessment. Background technique [0002] The complexity of aircraft composite material system, structural characteristics and service environment makes multi-component and multi-type damage modes inevitable. The internal damage models are diverse and the parameters are huge. The sensitivity between local damage parameters and the measurable response of the structure is different. The linear mapping feature is obvious; and the number of external sensors is far less than the number...

AI Technical Summary

Problems solved by technology

Although the regularization method has a long history, it has never been applied to the identification of large-scale damage parameters of composite materials. Considering its dependence on parameter settings, it can be said that it does not have the possibility of application

Since the damage is only a local quantity, if the redundant variables are not screened out, a large number of parameters to be identified will be meaningless parameters, and only by developing the algorithm without paying attention to the characteristics of the problem can only achieve little effect

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