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Engineering structure damage active monitoring lamb wave time-reversal focusing method

A technology of time-reversal focusing and engineering structure, which is applied in the analysis of solids and other directions using sonic/ultrasonic/infrasonic waves, which can solve the problems of difficult to obtain damage scattering signals, unsatisfactory online structure, and non-directionality.

Active Publication Date: 2008-04-30
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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Problems solved by technology

However, the current signal time-reversal focusing methods are all implemented under relatively complex equipment conditions, which have high requirements for sensor / actuator arrays, signal generators, data acquisition equipment, etc., which obviously do not meet the requirements of online structural damage monitoring. At the same time, in the active Lamb wave damage monitoring of plate structures, the Lamb wave propagation is non-directional, and each sensor is receiving the time-reversed signal excited by each sensor while receiving the damage-focused enhanced scattering signal. will stack together indistinguishable
Therefore, in active Lamb wave structural health monitoring technology, it is difficult to obtain focusing-enhanced damage scattering signals using conventional equipment and methods, and new processing methods and technologies must be used to focus and collect damage scattering signals

Method used

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  • Engineering structure damage active monitoring lamb wave time-reversal focusing method
  • Engineering structure damage active monitoring lamb wave time-reversal focusing method
  • Engineering structure damage active monitoring lamb wave time-reversal focusing method

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Embodiment Construction

[0044] In this embodiment, the layout of the test piece and the piezoelectric element as shown in Fig. 2(a) is adopted. The test piece is a carbon fiber reinforced composite material plate with a size of 500mm×500mm×3mm, and the number of piezoelectric elements is 4, of which 3 elements are arranged in symmetrical positions. In order to investigate the influence of distance on the signal, the last piezoelectric element is offset symmetrically The position is 50mm, with the lower left corner of the test piece as the coordinate origin, the coordinates of the four piezoelectric elements are 1 (175mm, 175mm), 2 (175mm, 325mm), 3 (325mm, 375mm), 4 (325mm, 175mm). In the embodiment, the occurrence of damage is simulated by loading weights, the loading position coordinates are (250mm, 285mm), and the diameter is 19mm.

[0045] As shown in Figure 4, the present embodiment includes the following steps:

[0046] (1) Acquisition of structural response signals:

[0047] As shown in Figu...

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Abstract

The invention discloses a method of focusing by time reversal for Lamb wave in actively monitoring the engineering structural damage. The method includes the following steps: step one: collecting the damage dispersion signals; step two: carrying out time reversing treatment; and step three: focusing the damage dispersion signals. By sue of the sensor / stimulator array technology, and based on the prior structural damage monitoring equipment, the invention, having no necessity of any other special equipment, adopts the convolution operation to focus the Lamb wave signals in the damage monitoring system, improves the signal to noise ratio of the damage dispersion signals, and simplifies the method of extracting the characteristic parameters, thereby enhancing the accuracy and the stability of the monitoring system.

Description

1. Technical field [0001] The invention relates to a method for active Lamb wave damage monitoring of plate engineering structures, in particular to a method for realizing time-reversal focusing enhancement of active Lamb wave structure damage monitoring signals under the condition of conventional general-purpose equipment, thereby realizing engineering structure damage monitoring. 2. Background technology [0002] With the continuous improvement of structural safety and reliability requirements, the on-line monitoring and diagnosis of structural damage has attracted more and more attention. In order to prevent disasters or losses caused by structural damage, effective monitoring of structures is necessary. [0003] The on-line monitoring of structural damage requires that the relevant signal generation and acquisition equipment should be relatively simple, and the monitoring must have high real-time and accuracy. The damage monitoring of plate structures generally adopts th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N29/04
Inventor 袁慎芳王强邱雷孙亚杰
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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