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defect localization method for ferromagnetic pipes based on stepped magnetization in magnetic permeability perturbation testing

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INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING 2025年 214卷

作者： Deng, Zhiyang Qian, Dingkun Wang, Yushan Qi, Pan Yang, Nan Song, Xiaochun Kang, Yihua Hubei Univ Technol Key Lab Modern Manufacture Qual Engn Wuhan 430068 Peoples R China China Nucl Power Operat Technol Co Ltd Wuhan Peoples R China Huazhong Univ Sci & Technol Wuhan 430074 Peoples R China

The magnetic permeability perturbation testing (MPPT) method is effective for evaluating thick-walled steel pipes. However, determining the burial depth of a defect directly from a single time-domain signal faces challenge. The concept of magnetization layering is introduced, and a defect localization method based on stepped magnetization for ferromagnetic pipes is proposed, which focuses on the change of magnetization layering due to the non-uniform magnetization. The detection signals are acquired under a magnetic field with a step change in intensity, and the defects are localized by the characteristic current I Delta V. The relationship between the characteristic current and the magnetization depth h is verified by equivalent magnetic circuit analysis and finite element simulation analysis. Experiments on different buried defects verify that the characteristic current I Delta V can reflect the buried depth of defects. Finally, some key dimensional parameters of the magnetizer are discussed and optimized. The method is of great practical value for localizing defects from the signal source, which applies to different ferromagnetic pipes.

关键词： Stepped magnetization Magnetic permeability perturbation defect localization Ferromagnetic pipe

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defect localization for Power Cables With Chirp Z Transform of Reflection Coefficient Spectrum

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IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION 2025年第1期32卷 551-560页

作者： Li, Yuan Zhou, Hao Xu, Yefei Zhou, Kai Rao, Xianjie Sichuan Univ Coll Elect Engn Chengdu 610065 Peoples R China State Grid Sichuan Elect Power Co Chengdu 611133 Peoples R China

Frequency-domain reflection (FDR) has been proved promising to locate the defect of power cables, yet the traditional fast Fourier transform (FFT)-based algorithm faces problems, including low localization resolution and high data redundancy, resulting in lower accuracy of the defect localization results. In this article, we proposed a defect localization method for power cables based on chirp Z transform of reflection coefficient spectrum. The method can arbitrarily adjust the resolution of the defect localization function with chirp Z transform algorithm, thereby obtaining better localization effect at the same sampling points compared with FFT, and also reduces the data redundancy and eliminates the influence of interference peaks. The simulations of the method on artificially defected cables prove its accuracy to identify cable defects of different types, levels, and locations. The maximum absolute localization error was only 0.65 m and is less affected by the number of sampling points. Field tests on actual 256-m/10-kV cables with shielding layer corrosion and 500-m/10-kV cables with shielding layer rupture and loose wrapping further verified the effectiveness of the method, with defect localization errors of 0.64% and 0.21%, respectively. Simulation and field test results prove that the proposed method can effectively locate defects of power cables with higher accuracy and correctness.

关键词： Location awareness Reflection coefficient Power cables Chirp Impedance Reflection Mathematical models Chirp Z transform cross-linked polyethylene (XLPE) power cable defect localization frequency-domain reflection (FDR) reflection coefficient spectrum

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defect localization in heterogeneous plate structures using the geometric phase change - index of Lamb waves

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ULTRASONICS 2025年 152卷 107654页

作者： Zhang, Guangdong Kundu, Tribikram Deymier, Pierre A. Runge, Keith Univ Arizona New Frontiers Sound Sci & Technol Ctr Tucson AZ 85721 USA Univ Arizona Dept Aerosp & Mech Engn Tucson AZ 85721 USA Univ Arizona Dept Civil & Architectural Engn & Mech Tucson AZ 85721 USA Univ Arizona Dept Mat Sci & Engn Tucson AZ 85721 USA

defect localization in homogeneous structures using ultrasonic waves is relatively easy to implement. However, locating defects in heterogeneous structures made of different materials can be challenging. This is because complicated reflections, refractions and scatterings occur when ultrasonic waves pass through the interfaces between two dissimilar materials of the heterogeneous structures. To address this issue, a localization methodology based on geometric phase change - index (GPC-I), derived from topological acoustic (TA) sensing, is proposed to adapt to the complicated scenarios when defects are present in heterogeneous plate structures. The GPC-I is adopted as the damage index (DI) to present the possibility of defects appearing on different acoustic sensing paths. A maximum peak value-dependent threshold in GPC-I plots (GPC-I vs. sensor sites) is defined to filter out unreliable sensing paths resulting from the heterogeneity. Different sensing modes (I and II) are combined to comprehensively provide a more reliable and accurate localization framework. Numerical modeling carried out by Abaqus/CAE software verifies the proposed GPC-I based localization technique. Comparison results among GPC-I and other two commonly used acoustic parameters-wave velocity differences (VD) and amplitude ratio (AR) (or wave attenuation) show that the GPC-I has superiority with higher sensitivity and stability for defect localization. This work can provide promising guidance for localizing defects in complex heterogeneous plate structures used in real-world engineering applications.

关键词： defect localization Topological acoustic (TA) sensing Geometric phase change - index (GPC-I) Maximum peak value-dependent threshold Heterogeneous plate structures

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defect localization in plate structures using the geometric phase of Lamb waves

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ULTRASONICS 2025年 145卷 107492页

Commonly used methods for defect localization in structures are based on velocity differences (VD) or amplitude ratio (AR) (or attenuation due to scattering) measured along different sensing paths between a reference system and a defective system. A high value on a sensing path indicates a higher probability of the presence of defect on that path. We introduce an alternative approach based on the newly developed topological acoustic (TA) sensing technique for localizing defects in plate structures using Lamb waves. TA sensing exploits changes in geometric phase of acoustic waves to detect perturbations in the supporting medium. This approach uses a geometric phase change - index (GPC-I), a measure of the geometry of the acoustic field averaged over a spectral domain, as detection metric in lieu of VD or AR. Calculations based on the finite element method (FEM) in Abaqus/CAE software verifies the effectiveness of the proposed GPC-I-based defect localization method. Randomly located defects on the surface of a plate are localized with higher sensitivity and accuracy, by the GPC-I method in comparison to VD or AR-based methods.

关键词： defect localization Topological acoustic sensing Geometric phase change - index (GPC-I) Lamb waves Structural health monitoring

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An EMPECT-based defect localization method for multilayered structures using high-order statistical analysis and high-frequency component separation strategy

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NDT & E INTERNATIONAL 2025年 154卷

作者： Yang, Shuyan Zhang, Jizhou Fan, Siwei Lu, Guohang Yan, Shunping Fan, Zhigeng Wan, Qiang Zhang, Shuxin Li, Lifeng Chen, Zhenmao Xie, Shejuan Xi An Jiao Tong Univ Shaanxi Engn Res Ctr Nondestruct Testing & Struct State Key Lab Strength & Vibrat Mech Struct Xian 710049 Peoples R China China Acad Engn Phys Inst Syst Engn Mianyang 621999 Sichuan Peoples R China China Natl Petr Corp Tubular Goods Res Inst Xian 710077 Peoples R China State Key Lab Oil & Gas Equipment Xian 710065 Shaanxi Peoples R China

The multilayered metallic structures are widely used in industrial fields. For these structures, the internal corrosion defects happening in the process of manufacture and service may seriously affect the availability and safety of the structure and even the whole equipment. In this study, to achieve the effective detection and localization of the internal corrosion defects distributed in different layers, based on energy-management pulsed eddy current testing method, a novel high-order signal feature and a new defect localization method on the basis of high-frequency component separation are proposed. The superiority of the novel high-order signal feature is verified through numerical simulation and experiments. Compared with traditional signal feature, the novel high-order signal feature is able to detect smaller-sized defects and has higher signal-to-noise ratio. The validation of the new defect localization method is proved by experiments. The macro accuracy of the proposed localization method is 91.67 % and this method is still effective for the defect with stepped depth.

关键词： EMPECT method Multilayered structures High-order statistical analysis Frequency component separation defect localization

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Category-Agnostic Cluster-Guided Selective Suppression for Weakly Supervised Surface defect localization

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2025年 74卷

作者： Jiang, Shuai Liu, Min Liu, Yuxi Ma, Yunfeng Wang, Yaonan Hunan Univ Coll Elect & Informat Engn Changsha 410082 Hunan Peoples R China Hunan Univ Natl Engn Res Ctr Robot Visual Percept & Control Changsha 410082 Hunan Peoples R China

Surface defect localization is indispensable for the quality control of industrial products in the manufacturing process, supervised dense prediction of defect areas requires laborious and difficult pixel-level annotations. On the contrary, weakly supervised defect localization (WSDL) is much more practicable, and the class activation maps (CAMs) generated with image-level labels can serve as prior knowledge or cues for downstream tasks. However, due to interference of unforeseen background objects that may have high confidence in activation maps instead, the localization maps obtained from general WSDL methods are prone to be unreliable, which leads to errors or even missing localization. Therefore, in this article, we innovatively propose a simple, yet effective cluster-guided selective suppression (CSS) strategy for weakly supervised surface defect localization, aiming at the rectification of CAMs, thus producing more reliable localization maps. Specifically, CSS leverages converted rectangle patch pairs generated from CAMs and performs unsupervised vector-level cluster analysis, all patches are classified into defective or nondefective clusters. Subsequently, a category-agnostic cluster is selected to provide suppression feedback for the image suppressor, and the suppressed images are recycled for feature re-learning. Extensive experimental results demonstrate that our proposed method achieves state-of-the-art WSDL performance on three public datasets of metal and magnetic-tile surfaces, with average classification and localization accuracy improved by 7.19% and 5.40%, respectively.

关键词： Location awareness Inspection Cams Training Production Manufacturing Weak supervision Annotations Surface treatment Quality control defect localization intelligent manufacturing surface defect inspection system weakly supervised learning

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A Two-Stage YOLOv5s-U-Net Framework for defect localization and Segmentation in Overhead Transmission Lines

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SENSORS 2025年第9期25卷 2903页

作者： Li, Aohua Li, Dacheng Wang, Anjing Hefei Univ Technol Sch Mech Engn Hefei 230009 Peoples R China Chinese Acad Sci Anhui Inst Opt & Fine Mech Key Lab Gen Opt Calibrat & Characterizat Technol Hefei 230031 Peoples R China

Transmission-line defect detection is crucial for grid operation. Existing methods struggle to balance defect localization and fine segmentation. Therefore, this study proposes a novel cascaded two-stage framework that first utilizes YOLOv5s for the global localization of defective regions, and then uses U-Net for the fine segmentation of candidate regions. To improve the segmentation performance, U-Net adopts a transfer learning strategy based on the VGG16 pretrained model to alleviate the impact of limited dataset size on the training effect. Meanwhile, a hybrid loss function that combines Dice Loss and Focal Loss is designed to solve the small-target and class imbalance problems. This method integrates target detection and fine segmentation, enhancing detection precision and improving the extraction of detailed damage features. Experiments on the self-constructed dataset show that the method achieves 87% mAP on YOLOv5s, 88% U-Net damage recognition precision, a mean Dice coefficient of 93.66%, and 89% mIoU, demonstrating its effectiveness in accurately detecting transmission-line defects and efficiently segmenting the damage region, providing assistance for the intelligent operation and maintenance of transmission lines.

关键词： transmission-line defects defect localization semantic segmentation YOLOv5s U-net two-stage framework

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defect localization using physical design and electrical test information 11

Defect localization using physical design and electrical tes...

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11th Annual IEEE/SEMI Advanced Semiconductor Manufacturing Conference and Workshop (ASMC 2000)

作者： Stanojevic, Z Balachandran, H Walker, DMH Lakhani, F Jandhyala, S Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA

ISBN: (纸本)0780359216

In this work we describe an approach of using physical design and test failure knowledge to localize defects in random logic. We term this approach computer-aided fault to defect mapping (CAFDM). An integrated tool has been developed on top of an existing commercial ATPG tool. CAFDM was able to correctly identify the defect location and layer in all 9 of the chips that had bridging faults injected via FIB. Preliminary failure analysis results on production defects are promising.

关键词： defect diagnosis testing failure analysis fault diagnosis fault localization defect localization fault isolation defect isolation

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defect localization and Optimization of PIND for Large Size CQFP Devices 22

Defect Localization and Optimization of PIND for Large Size ...

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22nd International Conference on Electronic Packaging Technology (ICEPT)

作者： Wang, Shinan Ma, Yong Zhang, Kaihong Yu, Yongjian Wan, Yongkang Xie, Weikun Corp 58 Res Inst China Elect Technol Grp Wuxi Jiangsu Peoples R China

ISBN: (纸本)9781665413916

CQFP devices have been widely used in aerospace, military and other fields due to the advantages of high reliability[1], but large-size CQFP devices are prone to failure after PING test. This paper uses ANSYS Workbench to locate the defect and verify it by scanning electron microscope (SEM). The verification results are consistent with the simulation results. In addition, a test fixture was used to optimize the PIND test process, and the results show that the use of test fixture can effectively reduce the risk of device failure.

关键词： Large-Size CQFP Device PIND defect localization FEM Optimization

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Mechanism and Method for Outer Raceway defect localization of Ball Bearings

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IEEE ACCESS 2020年 8卷 4351-4360页

作者： Zhang, Feibin Huang, Jinfeng Chu, Fulei Cui, Lingli Tsinghua Univ Dept Mech Engn Beijing 100084 Peoples R China Beijing Univ Technol Beijing Engn Res Ctr Precis Measurement Technol & Beijing 100124 Peoples R China

The localization of outer raceway defect plays a significant role in malfunction elimination, failure cause analysis as well as the residual life prediction of ball bearings. Based on the nonlinear dynamic model for a ball bearing and the outer raceway defect model considering the ball finite size, this article employs the detailed mathematical derivation and theoretical analysis of the load distribution for the bearing system with an outer raceway defect located at the different angular positions. Therefore, the essential mechanism of the approximate linear relationship between the proposed indices, namely horizontal-vertical synchronized Peak (HVSPeak) and horizontal-vertical synchronized RMS (HVSRMS), and the defect angular position is explained. More importantly, it is theoretically demonstrated that HVSRMS is approximately a cotangent function with the defect angular position as the only variable, which indicates that the index has excellent anti-interference and practicability. In addition, the superiority and necessity of the HVSRMS index can be seen when compared to HVSPeak, RMS, SampEn and Lemple-Ziv. It is validated through simulation and experiment results that HVSRMS index can efficiently diagnose the angular position of outer raceway defect. Finally, the signal denoising methods for HVSRMS are compared and studied, which indicates the direction for subsequent research.

关键词： defect localization HVSRMS ball bearing fault diagnosis

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