Damage detection method based on instantaneous phase changing degree

An instantaneous phase and damage detection technology, which is applied in the processing of detection response signals, and the use of sound waves/ultrasonic waves/infrasonic waves to analyze solids, etc., can solve the problem of inability to effectively eliminate noise, detection wave signal noise interference, and inability to correctly evaluate damage scattering Wave signal ToF and other issues

Inactive Publication Date: 2011-03-30
GARBSEN ELECTRIC SHANGHAI CO LTD
View PDF3 Cites 27 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the actual working environment, the detection wave signal may be disturbed by uncertain noise
If the noise energy is distributed within the frequency band of the target

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Damage detection method based on instantaneous phase changing degree
  • Damage detection method based on instantaneous phase changing degree
  • Damage detection method based on instantaneous phase changing degree

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0037] The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

[0038] In the embodiment, a 5-cycle sinusoidal AM pulse modulated by a Hanning window with a center frequency of 300 kHz is used as an excitation signal to excite Lamb waves. The acquisition time of each signal was set to 200 μs. Four circular piezoelectric strain gauges are fixed on the surface of an aluminum plate (600mm×600mm×2.0mm), enclosing a detection area of ​​400mm×400mm, such as image 3 (a) shown. The selected sensing paths of the six excitation-induction wave signals adopt the working mode of "one sending and one receiving" to excite and collect Lamb wave signals, covering the detection area, such as ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a damage detection method based on instantaneous phase changing degree in the technical field of mechanical structural detection, comprising the following steps: fixing an energy converter on the surface of an object to be detected or inlaying the energy converter in the structure of the object to be detected and constructing a detection area; detecting and calculating the objected to be detected in a non-damage state by utilizing ultrasonic guided wave to obtain the flight time of the wave signal scattered by the damage; calculating to obtain the damaged coordinate position by adopting a triangle positioning method according to the flight time, and drawing multiple coordinate tracks by combining ToF assessed by each sensing path in a sensing network, wherein the converging area of the coordinate tracks is the area in which the damage can appear. The method of the invention has preferable ability of resisting the random noise interference; even though signal noise ratio (SNR) of the collected wave signal is lower, the method still can be used for accurately assessing the ToF scattered by the damage in a basic order symmetrical (S0) mode, and further successfully identifies and positions the damage by combining a triangle positioning method.

Description

technical field [0001] The invention relates to a method in the technical field of mechanical structure detection, in particular to a damage detection method based on instantaneous phase change. Background technique [0002] In the past two decades, ultrasonic guided waves (such as Lamb waves) have been widely used in the field of non-destructive health testing. The damage identification method based on ultrasonic guided waves usually uses the wave signal collected when the specimen is not damaged as the reference wave signal, and compares the currently collected detection wave signal with the reference wave signal, thereby extracting the wave scattered by the damage. The characteristic information of the signal, such as time of flight (ToF), can achieve the purpose of damage identification and location. Since the inevitable dispersion characteristics of ultrasonic guided waves and the noise in the working environment seriously reduce the signal-to-noise ratio (SNR) of the ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N29/12G01N29/44
Inventor 苗晓婷李富才孟光
Owner GARBSEN ELECTRIC SHANGHAI CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products