Nonlinear ultrasonic mixing method for testing in structural fatigue crack direction

A nonlinear ultrasonic and fatigue cracking technology, applied in the analysis of solids using sound waves/ultrasonic waves/infrasonic waves, material analysis using sound waves/ultrasonic waves/infrasonic waves, and measuring devices

Active Publication Date: 2018-11-23
BEIJING UNIV OF TECH
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However, there are few reports in domestic and foreign literature on the use ...

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  • Nonlinear ultrasonic mixing method for testing in structural fatigue crack direction
  • Nonlinear ultrasonic mixing method for testing in structural fatigue crack direction
  • Nonlinear ultrasonic mixing method for testing in structural fatigue crack direction

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Embodiment Construction

[0063] Combine below Figure 1 to Figure 10 , taking the finite element simulation of shear wave mixing and A0 wave mixing detection as an example, the implementation process of the nonlinear ultrasonic mixing method for structural fatigue crack direction detection is explained in detail.

[0064] Abaqus commercial finite element analysis software was used to establish a two-dimensional finite element model of shear wave mixing and a three-dimensional finite element model of A0 wave mixing with two fatigue cracks in arbitrary directions, respectively, and carry out numerical simulation of shear wave mixing detection and A0 wave mixing detection. In the shear wave mixing simulation model, the fatigue crack length is 15mm, and the directions are 23° and 52°; in the A0 wave mixing simulation model, the fatigue crack length is 30mm, and the directions are 13° and 35°.

[0065] (1) Detection of fatigue crack direction in block structure

[0066] The specific implementation steps o...

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Abstract

The invention discloses a nonlinear ultrasonic mixing method for testing in the structural fatigue crack direction, and belongs to the field of non-destructive testing. The method comprises the following steps: firstly, according to a tested object and a nonlinear ultrasonic mixing harmonic condition, determining the testing parameters such as the mode, frequency, incident angle and the like of two fundamental frequency waves; performing the nonlinear ultrasonic mixing testing of the structural fatigue crack; performing continuous wavelet transformation on testing signals in each annular receiving point, extracting the amplitudes of mixing waves, and performing the mixing sound field directivity analysis; finally, calculating the fatigue crack direction according to the change rule of thereflecting mixing wave propagation direction along with the fatigue crack direction.

Description

technical field [0001] The invention relates to a non-linear ultrasonic detection method for fatigue crack direction, in particular to a non-linear ultrasonic mixing detection method for fatigue crack direction based on the directivity of the mixed-frequency sound field. The method is suitable for detecting the direction of fatigue cracks in block structures and plate structures, and belongs to the field of nondestructive testing. Background technique [0002] Fatigue cracks are one of the main causes of structural failure, and cracks in different directions have different degrees of damage to the structure. When the crack direction is perpendicular to the bearing surface of the structure, even a tiny fatigue crack can grow rapidly under alternating loads, leading to structural fracture. Therefore, in order to eliminate potential safety hazards and ensure the safe and stable operation of equipment, an effective method is urgently needed to detect the direction of fatigue cr...

Claims

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Application Information

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IPC IPC(8): G01N29/12G01N29/07G01N29/04
CPCG01N29/041G01N29/07G01N29/12G01N2291/011G01N2291/014G01N2291/023G01N2291/0237G01N2291/0258G01N2291/0289
Inventor 焦敬品吕洪涛吴斌何存富
Owner BEIJING UNIV OF TECH
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