Ultrasonic guided-wave defect locating method based on Liapunov index

Abstract

The invention discloses an ultrasonic guided-wave defect locating method based on Liapunov index, and the method is as follows: constructing a duffing oscillator signal detection system on the basis of duffing equation, calculating the Liapunov index variable with driving force F change; exciting ultrasonic guided wave signals on a to-be-tested material through an emitter, traversing all positions of the to-be-tested material with the ultrasonic guided wave signals, and obtaining an actually measured signal by a receiver; constructing a window function, intercepting, from the actually measured signal, interception signals with length corresponding to different window length, inputting each interception signal into theinterception signal, calculating the Liapunov index with driving force F change after the interception signals are inputted; determining the interception signal corresponding to the window length of greatest driving force F change amount, moving the window function to scan the interception signal for defect locating of the to-be-tested material. The ultrasonic guided-wave defect locating method can be used for ultrasonic guided wave signal identification, locating of defects in different degrees of injury, and improvement of the sensitivity of ultrasonic guided wave identification of small defects.

Description

technical field [0001] The invention relates to the technical field of ultrasonic guided wave detection, in particular to a method for locating defects with ultrasonic guided waves based on the Lyapunov index. Background technique [0002] In recent years, pipeline transportation has been widely used in various industries. It is one of the important components of comprehensive transportation in the national economy, and it is also the main symbol to measure whether a country's energy and transportation industries are developed. However, frequent pipeline accidents caused by factors such as environmental impact and man-made sabotage have caused serious national economic losses and casualties. Therefore, it is necessary to perform health detection on pipelines. Ultrasonic guided wave inspection has become an important method for long-distance pipeline inspection. Compared with traditional ultrasonic nondestructive testing, ultrasonic guided wave has the advantages of fast det...

AI Technical Summary

Problems solved by technology

However, the detection of weak signals using chaotic systems is mainly based on the detection of sine and cosine signals; the recognition of ultrasonic guided wave signals is a new application in recent years, and is still in the stage of theoretical exploration. For the workers in the industry, the main difficulty lies in the sensitivity Parameter setting of the detection system and defect parameter identification

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