Anisotropic damage identification method for composite material laminated structure

A composite material layer and identification method technology is applied in the field of anisotropic damage identification of composite material laminate structures, and can solve the problems of no application, little effect, and meaningless parameters of the parameters to be identified.

CN113740425AActive Publication Date: 2021-12-03BEIHANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2021-12-03

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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.
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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...

Examples

Embodiment

[0054] In order to more fully understand the characteristics of the invention and its applicability to engineering practice, the present invention verifies the method for a composite laminated structure subjected to tensile load as shown in FIG. 2 .

[0055] The model information and sensor layout of the composite structure are shown in Figure 2. The material of the laminate is T300 / 5208, and the layup sequence is (45° / -45° / 90° / 0°) s , Single layer thickness 0.125mm. Among them, 5 piezoelectric sensors surround the hole edge area where the structure may be damaged, and 9 strain measurement points are located near the hole edge area, which is close to the stress concentration area of ​​the structure. Define the center frequency of the 5-peak narrow-band sinusoidal excitation signal used as 100kHz, and measure the propagation velocity V of the wave packet corresponding to the Lamb wave in the structure in all directions at this frequency g (θ), such as image 3 shown.

[0056...