Method for detecting defects of metal bellows based on laser vibration

A technology for metal bellows and vibration detection, which is applied in measuring devices, using sound waves/ultrasonic waves/infrasonic waves to analyze solids, and using sound waves/ultrasonic waves/infrasonic waves for material analysis, etc. It can solve problems such as increasing the difficulty of laser vibration data collection

Inactive Publication Date: 2016-04-20
AEROSUN CORP +1
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

However, vibration-based damage detection requires synchronous measurement of the local or overall vibration of the bellows, the dynamic characteristics (such as natural frequency) of the bellows are extracted by measuring the vibration time to reveal the existence of damage, and the vibration of the abnormal point is used to locate Therefore, not only the problem of how to extract the dynamic characteristics from the signal with nonlinear noise, but also how to correlate the damage indicators of physical measurements, find out the damage and locate the damage, and the bellows are different from conventional pressure vessels, the surface There are huge bending deformations (peaks and troughs), which increase the difficulty of laser vibration data acquisition

Method used

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  • Method for detecting defects of metal bellows based on laser vibration
  • Method for detecting defects of metal bellows based on laser vibration
  • Method for detecting defects of metal bellows based on laser vibration

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Embodiment 1

[0088] In the method for detecting metal bellows defects based on laser vibration in this embodiment, the metal bellows to be tested has a typical structure, such as figure 1 As shown, the outer diameter of the straight section of the bellows D o =278mm, average diameter D m =315.86mm, thickness h=1.44mm, number of layers n=1, wave number β=8, wave height h=39.3mm, wave pitch q=33mm, free length at both ends L=296mm, bellows are made of 304 stainless steel. The bellows has an artificial external defect in the middle of the 4th wave.

[0089] The main process of actual detection in this embodiment can be found in figure 2 ,Specific steps are as follows:

[0090] Step 1: Vibration excitation—use the PZT piezoelectric ceramic sensor to excite the detected metal bellows, fix the bottom of the metal bellows, attach the PZT piezoelectric ceramic sensor to the first wave position of the bellows, and use the piezoelectric power amplifier ( PiezoPowerAmplifier) ​​amplifies the inp...

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Abstract

The invention relates to a method for detecting defects of metal bellows based on laser vibration and belongs to the field of nondestructive testing technology. The method comprises steps of vibrational excitation, determination of frequency, line scanning, obtaining of coordinates and the like. By the theory of boundary effect, two mutually perpendicular operation deformation vibration (ODS) scanning curves are processed to obtain 10 damage indexes for evaluating defect positions. By the Doppler effect of vibration measurement with laser, vibration information of metal bellows can be obtained conveniently and rapidly. The method of the invention has remarkable advantages of high sensitivity and precision, enhanced efficiency, reliable data, visual result, controllable precision, online detection, remote control and the like.

Description

technical field [0001] The invention relates to a method for detecting defects of metal bellows, in particular to a method for detecting defects of metal bellows based on laser vibration, and belongs to the technical field of non-destructive testing. Background technique [0002] Non-destructive testing technology is widely used in aerospace, construction, machinery, petrochemical, metallurgy and other fields. Traditional non-destructive testing mainly includes ultrasonic testing, magnetic particle testing, X-ray testing, penetrant testing and eddy current testing. However, these existing methods can only identify local damage, that is, only targeted small area defects can be identified in each inspection, and professionals are required to perform the inspection and interpret the results, which is cumbersome, time-consuming, and laborious. [0003] Laser vibration detection of product defects is a non-destructive testing technology developed later. Compared with the above-m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N29/04G01N29/12
CPCG01N29/045G01N29/043G01N29/12G01N2291/014G01N2291/0234G01N2291/0289
Inventor 白彭津刘永刘进江徐汝锋葛旸王明艳郑伟孙瑞晨黄新春张目
Owner AEROSUN CORP
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