Ultrasonic detecting method of defects in thick-wall composite tubular structure

Abstract

The invention discloses an ultrasonic detecting method of defects in a thick-wall composite tubular structure. The ultrasonic detecting method includes the steps that original signal data are obtained, final signal data are obtained with signal processing methods such as noise reduction, fast Fourier transforming and continuous wavelet transforming, and a wavelet-coefficient-amplitude-time graph is generated; according to the generated wavelet-coefficient-amplitude-time graph, the positions and the sizes of inside damage of a composite material layer and the positions and the sizes of the unsticking portions of the boundary between the composite material layer and a metal layer are extracted, and distribution of the thickness of the metal layer is calculated. The ultrasonic detecting method can be used for detecting the multiple defects of the tubular structure composed of composite materials and metal, damage positioning and size assessing are carried out through the corresponding signal processing technology, and quantitative analysis of the whole structure performance can be achieved; the ultrasonic detecting method is high in accuracy, free of reference signals, simple, easy to operate and capable of being used for field detecting.

Description

technical field [0001] The invention belongs to the technical field of nondestructive testing, and in particular relates to an ultrasonic testing method for defects in thick-walled composite tubular structures. Background technique [0002] Composite materials are widely used in aerospace, national defense, industry and other fields due to their excellent properties such as high strength, high rigidity, and good fatigue resistance. Composite tubular structures, as their basic structural methods, have also been greatly developed. The thick-walled composite tubular structure lined with metal combines the advantages of good performance of the full-composite tubular structure and low cost of metal gas cylinders, and has gradually become the main implementation method for gas cylinders, pipelines, oil tanks and other equipment. However, due to the complex manufacturing process and long service life of this structure, there will be various defects such as internal damage of the co...

AI Technical Summary

Problems solved by technology

But there are still some deficiencies, which are mainly reflected in: 1) the research object is only a simple small-scale structure of all-composite materials; 3) the research problem is mainly focused on the detection method of a single defect, and the diversity of defects in the structure is not considered; 2) Most detection methods are carried out under experimental conditions, and there are few feasible on-site real-time monitoring technologies; 4) Defect judgment requires intact signals as a benchmark

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