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Method for testing acoustic emission signal transmission characteristics of helicopter component based on harmonic wavelet packet

A technology of acoustic emission signals and propagation characteristics, which is applied in the processing of detection response signals and material analysis using acoustic emission technology. It can solve problems such as energy leakage and inflexible frequency band selection, and achieve the effect of overcoming energy leakage.

Inactive Publication Date: 2012-06-27
HARBIN UNIV OF COMMERCE
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Problems solved by technology

[0005] In order to solve the problems of energy leakage and inflexible frequency band selection in the analysis of the propagation characteristics of acoustic emission signals using traditional wavelet packets, a test method for the propagation characteristics of acoustic emission signals of helicopter components based on harmonic wavelet packets is provided

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  • Method for testing acoustic emission signal transmission characteristics of helicopter component based on harmonic wavelet packet
  • Method for testing acoustic emission signal transmission characteristics of helicopter component based on harmonic wavelet packet
  • Method for testing acoustic emission signal transmission characteristics of helicopter component based on harmonic wavelet packet

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specific Embodiment approach 1

[0037] Specific implementation mode 1: the following combination Figure 1 to Figure 6 In this embodiment, the method for testing the propagation characteristics of the acoustic emission signal of helicopter components based on the harmonic wavelet packet in this embodiment includes the following steps:

[0038] Arrange A acoustic emission sensors at equal intervals on the surface of the helicopter component to be tested, perform a standard lead breaking test on the helicopter component to be tested to generate test signals, and simultaneously collect the audio signals collected by A acoustic emission sensors, where A is a positive integer; The process of processing the signal collected by each acoustic emission sensor is the same, the specific process is:

[0039] Step 1: Collect the test signal x(r) obtained by each acoustic emission sensor, r=1, 2....N, N is the number of points of the collected test signal x(r), and is an integer greater than 2;

[0040] Step 2: Determine the nu...

specific Embodiment approach 2

[0057] Embodiment 2: This embodiment is a further description of Embodiment 1. The A is 6, and the 6 acoustic emission sensors are arranged at intervals of 50 mm from the helicopter component under test.

specific Embodiment approach 3

[0058] Specific embodiment 3: This embodiment is a further description of the first or second embodiment. The test signal x(r) adopts the average value of the test signal generated by multiple standard section lead tests of the helicopter component under test.

[0059] In this embodiment, the average value of the test signal obtained by multiple experiments is used as the basis of signal processing, which improves the accuracy of the collected signal.

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Abstract

A method for testing acoustic emission signal transmission characteristics of a helicopter component based on a harmonic wavelet packet belongs to the technical field of acoustic emission detection for mechanical helicopter components, and solves the problems of energy leakage and inflexibility of frequency band selection when the acoustic emission signal transmission characteristics are analyzed by a traditional wavelet packet. The method includes: acquiring testing signals obtained by an acoustic emission sensor; determining a decomposition layer number j and a frequency bandwidth B and computing an upper limiting frequency m and a lower limiting frequency n; computing frequency domain and frequency band values of harmonic wavelets; transforming the testing signals by means of FFT (fast Fourier transform) algorithm to obtain frequency domain discrete values; computing wavelet transform of the frequency domain and frequency band values; computing time-domain signals xl (r); obtaining energy E1 by means of transforming; and normalizing the energy E1 to obtain average energy and an energy diagram of the testing signals of the helicopter component to be tested, thereby obtaining the acoustic emission signal transmission characteristics of the helicopter component to be tested. The method is applicable to testing of the acoustic emission signal transmission characteristics of the helicopter component.

Description

Technical field [0001] The invention relates to a method for testing the propagation characteristics of acoustic emission signals of helicopter components based on harmonic wavelet packets, and belongs to the technical field of acoustic emission detection of helicopter mechanical components. Background technique [0002] The fatigue test of helicopter mechanical parts is an important means to determine the use timeliness of the main components of the helicopter and ensure the safe use of the helicopter. In the fatigue test of helicopter components, acoustic emission technology (AE) can be used to detect the initiation, location, and type of damage earlier, and can effectively find the damage location and degree of damage. Therefore, to carry out research on the acoustic emission detection technology of helicopter mechanical components, to further improve and improve the efficiency and accuracy of damage detection under the fatigue test state, is of great significance to accuratel...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N29/44G01N29/14
Inventor 于金涛梁廷伟王祁
Owner HARBIN UNIV OF COMMERCE
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