TOPOLOGICAL IMAGING IN LAYERED PLATE BY GUIDED WAVES
详细信息 查看官网全文
- 英文论文题名：TOPOLOGICAL IMAGING IN LAYERED PLATE BY GUIDED WAVES
- 论文作者：Chao ZHANG ; Shou-guo YAN ; Bi-xing ZHANG
- 英文论文作者：Chao ZHANG ; Shou-guo YAN ; Bi-xing ZHANG ; State Key Laboratory of Acoustics ; Institute of Acoustics ; Chinese Academy of Sciences ; University of Chinese Academy of Sciences
- 年：2016
- 作者机构：State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences;University of Chinese Academy of Sciences;
- 英文论文关键词：Layered plate ; Topological imaging ; Guided wave inspection ; Finite element method
- 会议召开时间：2016-10-21
- 会议录名称：2016年全国压电和声波理论及器件应用研讨会论文摘要集
- 英文会议录名称：Abstract Book of 2016 Symposium on Piezoelectricity, Acoustic Waves and Device Applications
- 语种：英文
- 分类号：TB302.5
- 学会代码：AGLU
- 会议名称：2016年全国压电和声波理论及器件应用研讨会
- 会议地点：中国陕西西安
- 主办单位：中国力学学会、中国声学学会、IEEE UFFC分会
- 学会名称：中国力学学会
- 页数：2
- 文件大小：93k
- 原文格式：D
- 会议级别：全国
摘要
Background, Motivation and Objective Layered plate is widely used in industry such as ship building and aerospace. One or several defects in layered plate could lead to decreasing service life of important structure, even cause unexpected accidents. Therefore, many techniques are proposed to detect defection including ultrasonic wave imaging. The guided wave has complex propagation characteristics because of frequency dispersion and multi-mode, which makes it difficult to locate the defect in waveguide structure. Some researchers have researched guided wave inspection on single-layer plate, but few articles about layered plate is published. Topological imaging is a recent method, it has already been applied for bulk waves imaging and has great advantages on defect imaging precisely. In this paper, the topological imaging with guided waves is applied to give the number and locations of existed defects in layered plate. Statement of Contribution/Methods In this method, an inspected plate(with defects) and a reference plate(without defects) are required. The two plates should have the same geometric dimensioning and mechanical parameters. Firstly, the formulas of the topological gradient are deduced theoretically. It is indicated that the defect position can be obtained by the topological gradient's extreme value. According to the method of the topological imaging with guided waves, the field solutions for situations are required,(i) the guided wave field in the reference plate excited by 1.5 cycles of sine wave modulated by Hanning window, it is called the forward problem.(ii) the acoustical field in the reference media excited by the time reversed signals of deference between the received signals of inspected plate and the signals from the first situation, it is called the adjoint problem. In the exciting process, a 30 elements phased array sensor is taken as the probe. Secondly, the imaging process is operated in Finite element software ANSYS. In order to verify the topological imaging method's adaptation to multiple defects situation, two inspected plate models are created in simulation. Two plates are all consist of an aluminum and steel layer. One and three defects are inserted in the steel layer of inspected plate I and II, respectively. Results According to the numerical simulation result for the inspected plate I, the location of the defect can be shown on the final image precisely with high resolution. For the inspected plate II, the three defects could be all located on the image but the resolution is not as high as that for the plate I. It reveals that the topological imaging method is suitable for defects inspection in waveguide structure and can be able to indicate all the defect locations by only one image. It is also found that the topological gradient distribution at the location of defect is similar to the incident signal, which means that the dispersion can be overcome by the time-reverse process in the adjoint problem. Besides, the topological imaging resolution in the case of wideband incident signal is higher than that of narrowband incident signal. Discussion and Conclusions Compared with classical ultrasonic imaging method, the topological imaging method could be applied on complicated structure. For the waveguide structure, the incident signal would be stretched in the time domain through in propagation process. The adjoint problem is similar to the time reversal process and can compensate the dispersion and the topological imaging could be obtained with high resolution. In this paper, it shows that the topological gradient distribution is just a function in space domain and could indicate the defects location at the extreme value point. It suggests that monitoring the distribution of topological gradient can be an efficient method to locate all the defects in layered plate.
Background, Motivation and Objective Layered plate is widely used in industry such as ship building and aerospace. One or several defects in layered plate could lead to decreasing service life of important structure, even cause unexpected accidents. Therefore, many techniques are proposed to detect defection including ultrasonic wave imaging. The guided wave has complex propagation characteristics because of frequency dispersion and multi-mode, which makes it difficult to locate the defect in waveguide structure. Some researchers have researched guided wave inspection on single-layer plate, but few articles about layered plate is published. Topological imaging is a recent method, it has already been applied for bulk waves imaging and has great advantages on defect imaging precisely. In this paper, the topological imaging with guided waves is applied to give the number and locations of existed defects in layered plate. Statement of Contribution/Methods In this method, an inspected plate(with defects) and a reference plate(without defects) are required. The two plates should have the same geometric dimensioning and mechanical parameters. Firstly, the formulas of the topological gradient are deduced theoretically. It is indicated that the defect position can be obtained by the topological gradient's extreme value. According to the method of the topological imaging with guided waves, the field solutions for situations are required,(i) the guided wave field in the reference plate excited by 1.5 cycles of sine wave modulated by Hanning window, it is called the forward problem.(ii) the acoustical field in the reference media excited by the time reversed signals of deference between the received signals of inspected plate and the signals from the first situation, it is called the adjoint problem. In the exciting process, a 30 elements phased array sensor is taken as the probe. Secondly, the imaging process is operated in Finite element software ANSYS. In order to verify the topological imaging method's adaptation to multiple defects situation, two inspected plate models are created in simulation. Two plates are all consist of an aluminum and steel layer. One and three defects are inserted in the steel layer of inspected plate I and II, respectively. Results According to the numerical simulation result for the inspected plate I, the location of the defect can be shown on the final image precisely with high resolution. For the inspected plate II, the three defects could be all located on the image but the resolution is not as high as that for the plate I. It reveals that the topological imaging method is suitable for defects inspection in waveguide structure and can be able to indicate all the defect locations by only one image. It is also found that the topological gradient distribution at the location of defect is similar to the incident signal, which means that the dispersion can be overcome by the time-reverse process in the adjoint problem. Besides, the topological imaging resolution in the case of wideband incident signal is higher than that of narrowband incident signal. Discussion and Conclusions Compared with classical ultrasonic imaging method, the topological imaging method could be applied on complicated structure. For the waveguide structure, the incident signal would be stretched in the time domain through in propagation process. The adjoint problem is similar to the time reversal process and can compensate the dispersion and the topological imaging could be obtained with high resolution. In this paper, it shows that the topological gradient distribution is just a function in space domain and could indicate the defects location at the extreme value point. It suggests that monitoring the distribution of topological gradient can be an efficient method to locate all the defects in layered plate.
Background, Motivation and Objective Layered plate is widely used in industry such as ship building and aerospace. One or several defects in layered plate could lead to decreasing service life of important structure, even cause unexpected accidents. Therefore, many techniques are proposed to detect defection including ultrasonic wave imaging. The guided wave has complex propagation characteristics because of frequency dispersion and multi-mode, which makes it difficult to locate the defect in waveguide structure. Some researchers have researched guided wave inspection on single-layer plate, but few articles about layered plate is published. Topological imaging is a recent method, it has already been applied for bulk waves imaging and has great advantages on defect imaging precisely. In this paper, the topological imaging with guided waves is applied to give the number and locations of existed defects in layered plate. Statement of Contribution/Methods In this method, an inspected plate(with defects) and a reference plate(without defects) are required. The two plates should have the same geometric dimensioning and mechanical parameters. Firstly, the formulas of the topological gradient are deduced theoretically. It is indicated that the defect position can be obtained by the topological gradient's extreme value. According to the method of the topological imaging with guided waves, the field solutions for situations are required,(i) the guided wave field in the reference plate excited by 1.5 cycles of sine wave modulated by Hanning window, it is called the forward problem.(ii) the acoustical field in the reference media excited by the time reversed signals of deference between the received signals of inspected plate and the signals from the first situation, it is called the adjoint problem. In the exciting process, a 30 elements phased array sensor is taken as the probe. Secondly, the imaging process is operated in Finite element software ANSYS. In order to verify the topological imaging method's adaptation to multiple defects situation, two inspected plate models are created in simulation. Two plates are all consist of an aluminum and steel layer. One and three defects are inserted in the steel layer of inspected plate I and II, respectively. Results According to the numerical simulation result for the inspected plate I, the location of the defect can be shown on the final image precisely with high resolution. For the inspected plate II, the three defects could be all located on the image but the resolution is not as high as that for the plate I. It reveals that the topological imaging method is suitable for defects inspection in waveguide structure and can be able to indicate all the defect locations by only one image. It is also found that the topological gradient distribution at the location of defect is similar to the incident signal, which means that the dispersion can be overcome by the time-reverse process in the adjoint problem. Besides, the topological imaging resolution in the case of wideband incident signal is higher than that of narrowband incident signal. Discussion and Conclusions Compared with classical ultrasonic imaging method, the topological imaging method could be applied on complicated structure. For the waveguide structure, the incident signal would be stretched in the time domain through in propagation process. The adjoint problem is similar to the time reversal process and can compensate the dispersion and the topological imaging could be obtained with high resolution. In this paper, it shows that the topological gradient distribution is just a function in space domain and could indicate the defects location at the extreme value point. It suggests that monitoring the distribution of topological gradient can be an efficient method to locate all the defects in layered plate.
引文