Detection method for detecting width of micro-crack on surface of material
A detection method, a technology for micro-cracks, applied in the direction of analyzing materials, material analysis using sonic/ultrasonic/infrasonic waves, measuring devices, etc.
Active Publication Date: 2016-09-21
BEIJING UNIV OF TECH
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Problems solved by technology
[0004] The purpose of the present invention is to solve the problem of detection of micro-cracks on the surface of materials by line-focused ultrasonic transducers, and propose a detection method for crack width
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Embodiment Construction
[0027] Step 1): Selection of finite element analysis model material and size parameters
[0028] Combined with actual and theoretical analysis, it is obtained that in order to increase the bandwidth characteristics of the transducer and improve the energy transmission efficiency, the model selects a 40 μm thick piezoelectric material PVDF film as the excitation / reception element, Tungsten loaded epoxy, 10% vf5.8Mray1 (referred to as back10) As the backing, water is selected as the coupling liquid, and the material of the test piece is aluminum to form a line-focusing transducer model, and the focusing radius of the transducer is 20mm. The material properties are shown in Table 1.
[0029] Table 1 Model material properties
[0030]
[0031] Step 2): Finite element analysis model establishment
[0032] Based on PVDF line focused ultrasound transducers, such as figure 1 As shown, the whole piezoelectric film is divided, and the finite element model of the dual-channel line-...
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The present invention discloses a detection method for detecting the width of a micro-crack on the surface of a material and belongs to the technical field of the non-destructive testing technology. The research on the detection method for detecting the width of the micro-crack on the surface of the material not only has important research significance on the material integrity evaluation, but also has important application value for the structure healthy and safety monitoring operation. According to the method, a dual-channel-line focused ultrasonic transducer model is established, and reception signals at different crack widths are analyzed. In this way, the method is an effective method for detecting micro-cracks on the surface of the material. The result of the method shows that, along with the width increasing of a crack, echo signals received by a channel 1 regularly change. Based on the above result, the detection and the quantitative characterization for the width of the micro-crack on the surface of the material can be realized. According to the method, the interference of a directly reflected echo on received signals on the surface of the material can be eliminated. Therefore, the defect-related information can be better extracted out of the received signals. The position of the micro-crack on the surface of the material can be detected, and the quantitative characterization for the width of the micro-crack on the surface of the material can be realized.
Description
technical field [0001] The invention designs a method for detecting the width of micro-cracks on the surface of materials based on PZFlex simulation software. The method is mainly used for the detection of micro-cracks on the surface of small test pieces by a line-focused ultrasonic microscope system, and belongs to the technical field of non-destructive testing. Background technique [0002] With the continuous development of material science, various functional materials are emerging and put into use. During the service process, the material is prone to cracks due to the action of stress. The cracks can be divided into micro cracks and macro cracks. The cracks that have been formed will continue to grow under the action of stress or environment (or both). This process is called crack propagation. The appearance and expansion of cracks significantly deteriorate the mechanical properties of the workpiece. These tiny surface cracks, whose width can be as small as microns, ar...
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Patent Timeline
Login to View More IPC IPC(8): G01N29/04G01N29/07G01B17/00
CPCG01B17/00G01N29/041G01N29/07G01N2291/011G01N2291/023
Inventor 宋国荣肖珍秦登千吕炎卢东邢智翔何存富吴斌
Owner BEIJING UNIV OF TECH