Composite material layered damage identification method based on contour and depth sequence identification

Abstract

The invention discloses a composite material layered damage identification method based on contour and depth sequence identification. The method comprises the steps of firstly, defining the layout of active piezoelectric sensors and passive strain sensors; secondly, carrying out active excitation and signal receiving on each piezoelectric sensor in sequence, and obtaining scattered waves of the damage through signal subtraction before and after the damage; then estimating the central position of the damage by using an alternating time reversal phase synthesis method, estimating boundary points of the layered damage by using the flight time of the direct wave in sequence, and performing damage boundary fitting based on the obtained multiple groups of boundary points; and thirdly, establishing a mathematical model for identifying the layering depth based on Bayesian posterior probability, updating a posterior probability model through strain measurement on the basis of the estimated damage boundary, and finally determining the layering depth. According to the method, a framework of active and passive information cooperative utilization is provided, reliable identification of the area and depth of the layered damage is achieved, the precision is high, and the practicability is high.

Description

technical field [0001] The present invention relates to the quantitative identification technology of multi-type damage of composite material structure, especially relates to the quantitative identification of delamination damage by combining active and passive information under sparse sensor layout after delamination damage occurs in composite material laminated structure The area and depth of the system provide a technical basis for real-time safety assessment of advanced structures in service. Background technique [0002] In recent years, composite materials have become more and more widely used in structural design in aviation, aerospace and other fields. Among various composite materials, carbon fiber reinforced composite laminated structures are widely used. However, with the long-term use of the structure and the diversification and unpredictability of the loading environment, the structural damage or even failure of the composite structure is inevitable. In order ...

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Problems solved by technology

[0005] The technical problem solved by the present invention is: to overcome the problem that the traditional layered damage identification method is difficult to take into account the sparsity of the sensor and the fineness of identification, combine the active Lamb wave signal with the passive strain, and use the Lamb wave to detect the damage boundary. Sensitivity and simplicity of surface strain measurement, a method for delamination damage identification of composite laminated structures is proposed that takes into account both damage contour and depth

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