Pub Date : 2025-12-01DOI: 10.1016/j.ndteint.2025.103616
Han Yan , Long Chao , Liu Zefang , Tan Chuandong , Zhou Jianing , Tan Hui , Duan Liming
Sparse-angle scanning can achieve rapid detection of laminated cells by the computed tomography (CT). Typically, sparse-angle scanning uses equiangular sparse angle to scan the object, which may overlook information-rich regions of the internal structure, leading to partial structural loss of the reconstructed images. This paper proposes a non-uniform sparse scanning angle selection method by analysing the discrepancies between the full sinograms and the equiangular sparse sinograms. Firstly, the equiangular sparse sinograms are obtained by an equiangular sparse operator applied to the full sinograms of the laminated cells. Then, the sinograms error curve is obtained by comparing the full sinograms with the equiangular sparse sinograms. Finally, a scanning angle selection model is designed, which can select scanning angles. The optimal experiment results show that our method increases PSNR by 3.7053 and improves SSIM by 0.1797. These results demonstrate that our method improves the quality of CT images while using the same number of scanning angles. Our method offers a novel idea for obtaining clearer CT reconstruction image under CT rapid scanning.
{"title":"Non-uniform scan angle selection for detecting cells via CT","authors":"Han Yan , Long Chao , Liu Zefang , Tan Chuandong , Zhou Jianing , Tan Hui , Duan Liming","doi":"10.1016/j.ndteint.2025.103616","DOIUrl":"10.1016/j.ndteint.2025.103616","url":null,"abstract":"<div><div>Sparse-angle scanning can achieve rapid detection of laminated cells by the computed tomography (CT). Typically, sparse-angle scanning uses equiangular sparse angle to scan the object, which may overlook information-rich regions of the internal structure, leading to partial structural loss of the reconstructed images. This paper proposes a non-uniform sparse scanning angle selection method by analysing the discrepancies between the full sinograms and the equiangular sparse sinograms. Firstly, the equiangular sparse sinograms are obtained by an equiangular sparse operator applied to the full sinograms of the laminated cells. Then, the sinograms error curve is obtained by comparing the full sinograms with the equiangular sparse sinograms. Finally, a scanning angle selection model is designed, which can select scanning angles. The optimal experiment results show that our method increases PSNR by 3.7053 and improves SSIM by 0.1797. These results demonstrate that our method improves the quality of CT images while using the same number of scanning angles. Our method offers a novel idea for obtaining clearer CT reconstruction image under CT rapid scanning.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103616"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Detecting the cure quality of adhesive in an adhesively bonded composite joint is crucial, as improper curing of adhesive in critical structural joints may compromise performance, durability, and service life. Since the composite adherend materials being bonded have poor thermal conductivity, ensuring that the adhesive reaches a proper cure temperature throughout the bonded region is challenging. While a large body of work exists on in-situ cure monitoring using thermocouples, dielectric, and other sensing elements, utilizing these sensing systems without compromising the adhesive layer is often challenging. Here, a frequency domain, non-destructive, post-cure assessment method has been explored using Broadband Dielectric Spectroscopy (BbDS) over 0.1Hz to 0.1 MHz range, which can identify whether the adhesive has appropriately been cured or not without exposing the bond. Bonded adhesive composite samples in lap-shear configuration with different levels of cure were manufactured by controlling the exposure time to the cure temperature. The stages of cure were verified using a Differential Scanning Calorimeter (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). Dielectric spectroscopy revealed significant differences in the Dielectric Relaxation Strength (DRS) with different levels of cure. Mechanical testing of bonds was carried out and a proportionate correlation was observed with degree of cure of the adhesive. The kinetics of cure mechanisms were also studied in a temperature-frequency dependent Dielectric Spectroscopy.
{"title":"Non-destructive adhesive cure assessment in carbon fiber reinforced composites using dielectric spectroscopy","authors":"Minhazur Rahman , Monjur Morshed Rabby , Vamsee Vadlamudi , Rassel Raihan","doi":"10.1016/j.ndteint.2025.103621","DOIUrl":"10.1016/j.ndteint.2025.103621","url":null,"abstract":"<div><div>Detecting the cure quality of adhesive in an adhesively bonded composite joint is crucial, as improper curing of adhesive in critical structural joints may compromise performance, durability, and service life. Since the composite adherend materials being bonded have poor thermal conductivity, ensuring that the adhesive reaches a proper cure temperature throughout the bonded region is challenging. While a large body of work exists on in-situ cure monitoring using thermocouples, dielectric, and other sensing elements, utilizing these sensing systems without compromising the adhesive layer is often challenging. Here, a frequency domain, non-destructive, post-cure assessment method has been explored using Broadband Dielectric Spectroscopy (BbDS) over 0.1Hz to 0.1 MHz range, which can identify whether the adhesive has appropriately been cured or not without exposing the bond. Bonded adhesive composite samples in lap-shear configuration with different levels of cure were manufactured by controlling the exposure time to the cure temperature. The stages of cure were verified using a Differential Scanning Calorimeter (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). Dielectric spectroscopy revealed significant differences in the Dielectric Relaxation Strength (DRS) with different levels of cure. Mechanical testing of bonds was carried out and a proportionate correlation was observed with degree of cure of the adhesive. The kinetics of cure mechanisms were also studied in a temperature-frequency dependent Dielectric Spectroscopy.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103621"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.ndteint.2025.103620
Cristian A. Calistru , Ehsan Mohseni , Vedran Tunukovic , S. Gareth Pierce , David Lines , Charles N. MacLeod , Randika K.W. Vithanage , Iain Bomphray , Tobias Weis , Gavin Munro , Tom O'Hare
Resin infusion paired with Out of Autoclave (OoA) curing offers an alternative to infrastructure-heavy autoclave-based manufacturing. However, lower fibre volume fractions and increased porosity from uneven resin flow limit the adoption of OoA processes in safety-critical applications. Consequently, there is demand for in-situ monitoring tools to track resin progression and ensure full permeation. Prior methods, including optical fibres and electromagnetic sensors, can infer front position but are intrusive or hard to scale. This research investigates leaky Lamb waves generated by ultrasonic transducers embedded in the top lid of an infusion mould. To isolate wave-fluid interactions, liquid-only measurements in a 2.0 mm thick infusion box are collected, removing laminate heterogeneity and enabling acquisition of controllable consecutive measurements, enabling the development and validation of predictive models under well-defined conditions. Attenuation of the fundamental antisymmetric mode (A0) as resin reaches the sensing region was demonstrated through theoretical and simulation-based analysis, highlighting the potential of Ultrasonic Guided Waves (UGW) for real-time fluid tracking. A custom experimental setup enabled consistent repeatable measurements of an advancing liquid front. A parametric study investigated the effects of geometry and fluid on signal amplitude, determining sensor spacing for sensitivity and areal coverage. Ultrasonic measurements were correlated with time-stamped images of the resin front through a machine-vision algorithm. Several functional approximation methods were applied to estimate liquid position from ultrasonic data, capturing the general trends in flow behaviour. The models yielded robust predictions, with mean errors of 5–7 % of the sensor spacing, despite environmental variations and system nonlinearities contributing to data variability.
{"title":"A step towards ultrasonic guided wave monitoring for resin infusion front position estimation in composites manufacturing","authors":"Cristian A. Calistru , Ehsan Mohseni , Vedran Tunukovic , S. Gareth Pierce , David Lines , Charles N. MacLeod , Randika K.W. Vithanage , Iain Bomphray , Tobias Weis , Gavin Munro , Tom O'Hare","doi":"10.1016/j.ndteint.2025.103620","DOIUrl":"10.1016/j.ndteint.2025.103620","url":null,"abstract":"<div><div>Resin infusion paired with Out of Autoclave (OoA) curing offers an alternative to infrastructure-heavy autoclave-based manufacturing. However, lower fibre volume fractions and increased porosity from uneven resin flow limit the adoption of OoA processes in safety-critical applications. Consequently, there is demand for in-situ monitoring tools to track resin progression and ensure full permeation. Prior methods, including optical fibres and electromagnetic sensors, can infer front position but are intrusive or hard to scale. This research investigates leaky Lamb waves generated by ultrasonic transducers embedded in the top lid of an infusion mould. To isolate wave-fluid interactions, liquid-only measurements in a 2.0 mm thick infusion box are collected, removing laminate heterogeneity and enabling acquisition of controllable consecutive measurements, enabling the development and validation of predictive models under well-defined conditions. Attenuation of the fundamental antisymmetric mode (A0) as resin reaches the sensing region was demonstrated through theoretical and simulation-based analysis, highlighting the potential of Ultrasonic Guided Waves (UGW) for real-time fluid tracking. A custom experimental setup enabled consistent repeatable measurements of an advancing liquid front. A parametric study investigated the effects of geometry and fluid on signal amplitude, determining sensor spacing for sensitivity and areal coverage. Ultrasonic measurements were correlated with time-stamped images of the resin front through a machine-vision algorithm. Several functional approximation methods were applied to estimate liquid position from ultrasonic data, capturing the general trends in flow behaviour. The models yielded robust predictions, with mean errors of 5–7 % of the sensor spacing, despite environmental variations and system nonlinearities contributing to data variability.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103620"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.ndteint.2025.103618
Yigang Cheng , Wenze Shi , Chao Lu , Weiwei Chen , Yujia Zeng , Bo Hu
High-temperature alloy bolts used in aerospace engines face some issues, such as high ultrasonic attenuation coefficient and low electrical conductivity compared to traditional metal materials. Common measurement methods encounter problems, including the impact of piezoelectric ultrasonic coupling agents on acoustic time accuracy, film easy shedding of permanent mounted transducer system (PMTS), and low SNR in EMAT measurements. To date, there are limited high-precision ultrasonic measurement technologies available for the preload of bolt fasteners in high-temperature alloy materials such as GH4169. This research introduces a technique for measuring the time of flight (TOF) of ultrasonic waves within bolts using Laser-electromagnetic acoustic transducer (Laser-EMAT) technology and determines the preload of bolts employing either the mono-wave method or the bi-wave method. Utilizing numerical simulation and experimental validation, the study analyses the ultrasonic wave modes and their SNR under three laser-induced mechanisms: thermoelastic, ablation, and surface constraint, in GH4169 bolts. We establish a linear relationship between acoustic TOF and bolt preload and compare the measurement accuracy of the mono- and bi-wave methods under these three laser-induced mechanisms. The research showed that: Under the thermoelastic mechanism, the average relative errors of the mono-wave method and bi-wave method in measuring 10 kN and above loads were lower than 4.2 %, 4.9 %, respectively. Although the ablation mechanism can improve the SNR of longitudinal waves compared with the thermoelastic mechanism, the measurement accuracy decreases. Using the surface constraint mechanism with silver-grease as the coating material, the SNR of longitudinal waves was improved by 13 dB compared with the thermoelastic mechanism. The mono-wave method with second longitudinal waves achieved higher accuracy than the first longitudinal wave approach, showing under 1.6 % average error at loads of 5 kN and above. This study offers a novel high-precision testing approach for measuring the preload in aerospace engine high-temperature alloy bolts with a high level of ultrasonic wave attenuation.
{"title":"Research on Laser-EMAT measurement of preload in high-temperature alloy bolts for aerospace applications","authors":"Yigang Cheng , Wenze Shi , Chao Lu , Weiwei Chen , Yujia Zeng , Bo Hu","doi":"10.1016/j.ndteint.2025.103618","DOIUrl":"10.1016/j.ndteint.2025.103618","url":null,"abstract":"<div><div>High-temperature alloy bolts used in aerospace engines face some issues, such as high ultrasonic attenuation coefficient and low electrical conductivity compared to traditional metal materials. Common measurement methods encounter problems, including the impact of piezoelectric ultrasonic coupling agents on acoustic time accuracy, film easy shedding of permanent mounted transducer system (PMTS), and low SNR in EMAT measurements. To date, there are limited high-precision ultrasonic measurement technologies available for the preload of bolt fasteners in high-temperature alloy materials such as GH4169. This research introduces a technique for measuring the time of flight (TOF) of ultrasonic waves within bolts using Laser-electromagnetic acoustic transducer (Laser-EMAT) technology and determines the preload of bolts employing either the mono-wave method or the bi-wave method. Utilizing numerical simulation and experimental validation, the study analyses the ultrasonic wave modes and their SNR under three laser-induced mechanisms: thermoelastic, ablation, and surface constraint, in GH4169 bolts. We establish a linear relationship between acoustic TOF and bolt preload and compare the measurement accuracy of the mono- and bi-wave methods under these three laser-induced mechanisms. The research showed that: Under the thermoelastic mechanism, the average relative errors of the mono-wave method and bi-wave method in measuring 10 kN and above loads were lower than 4.2 %, 4.9 %, respectively. Although the ablation mechanism can improve the SNR of longitudinal waves compared with the thermoelastic mechanism, the measurement accuracy decreases. Using the surface constraint mechanism with silver-grease as the coating material, the SNR of longitudinal waves was improved by 13 dB compared with the thermoelastic mechanism. The mono-wave method with second longitudinal waves achieved higher accuracy than the first longitudinal wave approach, showing under 1.6 % average error at loads of 5 kN and above. This study offers a novel high-precision testing approach for measuring the preload in aerospace engine high-temperature alloy bolts with a high level of ultrasonic wave attenuation.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103618"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.ndteint.2025.103614
Chuandong Tan , Zhiting Chen , Qi Li , Ao Wang , Fenglin Liu , Yufang Cai , Liming Duan
Computed laminography (CL) overcomes the dual limitations of X-ray energy constraints and mechanical structural restrictions inherent in computed tomography (CT), enabling high-resolution nondestructive imaging of plate-like objects. Nevertheless, existing CL imaging systems are constrained to single scanning modes, failing to meet diverse application requirements or support research on relevant CL theory and reconstruction algorithms. To address these challenges, we design a mode-switchable CL system (MSCL) that seamlessly transitions between multiple scanning configurations and can achieve various scanning trajectories, including circular, linear, and composite trajectories. This system achieves theoretical detail resolution at the micrometer (μm) level. Meanwhile, a software tool “CLRecTool” is created to process the projection data of different CL scanning modes collected using the TIGRE toolbox, achieving CL image reconstruction. Simulation and actual experiments evaluate the effects of scanning trajectories and reconstruction algorithms on imaging quality. This versatility and scalability establish MSCL as a critical experimental platform for advancing CL imaging theory and algorithm development, while accelerating CL technology's adoption in multi-scenario industrial applications.
{"title":"Mode-switchable computed laminography: System design and imaging analysis for plate-like objects","authors":"Chuandong Tan , Zhiting Chen , Qi Li , Ao Wang , Fenglin Liu , Yufang Cai , Liming Duan","doi":"10.1016/j.ndteint.2025.103614","DOIUrl":"10.1016/j.ndteint.2025.103614","url":null,"abstract":"<div><div>Computed laminography (CL) overcomes the dual limitations of X-ray energy constraints and mechanical structural restrictions inherent in computed tomography (CT), enabling high-resolution nondestructive imaging of plate-like objects. Nevertheless, existing CL imaging systems are constrained to single scanning modes, failing to meet diverse application requirements or support research on relevant CL theory and reconstruction algorithms. To address these challenges, we design a mode-switchable CL system (MSCL) that seamlessly transitions between multiple scanning configurations and can achieve various scanning trajectories, including circular, linear, and composite trajectories. This system achieves theoretical detail resolution at the micrometer (μm) level. Meanwhile, a software tool “CLRecTool” is created to process the projection data of different CL scanning modes collected using the TIGRE toolbox, achieving CL image reconstruction. Simulation and actual experiments evaluate the effects of scanning trajectories and reconstruction algorithms on imaging quality. This versatility and scalability establish MSCL as a critical experimental platform for advancing CL imaging theory and algorithm development, while accelerating CL technology's adoption in multi-scenario industrial applications.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103614"},"PeriodicalIF":4.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.ndteint.2025.103612
Yuedong Xie , Xiaoxuan Geng , Pu Huang , Yong Yan
Metallic plates are widely used in aerospace, transportation, and the chemical industry. Conductivity is a significant physical property of metal materials, and material aging and corrosion can be detected in timely to ensure the safe and stable operation of industrial equipment and systems through monitoring variation of conductivity. In order to achieve high-precision conductivity measurement, this paper innovatively investigated an eddy current testing (ECT) method incorporating a feedforward Proportion-Integration-Differentiation (PID) controller. Specifically, a closed-loop PID controller is introduced to act on classical Dodd-Deeds analytical model. Conductivity can be accurately inverted by continuously reducing the deviation between the output of the analytical model and actual measurements. Considering the lift-off fluctuation affects the conductivity measurement accuracy, a feedforward controller is designed to reduce the lift-off distance variation, and the transfer function of the feedforward controller can be obtained by theoretical deduction. Experiments are also conducted to verify the proposed method. Results indicate the maximum relative error of conductivity measurement remains merely 1.64 % across the 3 mm lift-off range, demonstrating the efficiency and reliability of the proposed method.
{"title":"A method for conductivity measurement through eddy current testing and closed-loop feedforward control","authors":"Yuedong Xie , Xiaoxuan Geng , Pu Huang , Yong Yan","doi":"10.1016/j.ndteint.2025.103612","DOIUrl":"10.1016/j.ndteint.2025.103612","url":null,"abstract":"<div><div>Metallic plates are widely used in aerospace, transportation, and the chemical industry. Conductivity is a significant physical property of metal materials, and material aging and corrosion can be detected in timely to ensure the safe and stable operation of industrial equipment and systems through monitoring variation of conductivity. In order to achieve high-precision conductivity measurement, this paper innovatively investigated an eddy current testing (ECT) method incorporating a feedforward Proportion-Integration-Differentiation (PID) controller. Specifically, a closed-loop PID controller is introduced to act on classical Dodd-Deeds analytical model. Conductivity can be accurately inverted by continuously reducing the deviation between the output of the analytical model and actual measurements. Considering the lift-off fluctuation affects the conductivity measurement accuracy, a feedforward controller is designed to reduce the lift-off distance variation, and the transfer function of the feedforward controller can be obtained by theoretical deduction. Experiments are also conducted to verify the proposed method. Results indicate the maximum relative error of conductivity measurement remains merely 1.64 % across the 3 mm lift-off range, demonstrating the efficiency and reliability of the proposed method.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103612"},"PeriodicalIF":4.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-25DOI: 10.1016/j.ndteint.2025.103610
Quan Zhang, Xiaohui Zhang, Hule Li, Shunhua Zhou, Naichen Shi, Chao He, Honggui Di
Rebar and steel fiber hybrid reinforced concrete (RC-SFRC) segments are gaining prominence in large-cross-section subway shield tunnel construction due to superior durability and crack resistance. However, conventional methods for evaluating steel fiber distribution and orientation face destructiveness and complexity, limiting large-volume concrete segment quality control applications. This study develops inductance-based techniques to enable nondestructive assessment of fiber distribution and orientation characteristics. On this basis, the research analyzes inductive method measurement-related engineering affecting factors, investigates fiber distribution characteristics and their effect on crack resistance in RC-SFRC segments. Experimental results demonstrate that inductance techniques exhibit robustness and efficiency for steel fiber characterization in tunnel segment applications. RC-SFRC segments' representative specimen dimensions of 50 mm radius for cylindrical and 90 mm edge length for cubic samples effectively reduce fiber content inductance-testing dispersion. Steel fiber distribution and orientation in the RC-SFRC segment show preferential distributions, featuring two significantly thickness-dependent dose distributions while preferentially orienting in the central angle direction, thereby reducing outer arc layer crack resistance capacity. Inductive-based orientation characterization can effectively communicate Barcelona testing fracture surfaces and post-cracking performance, significantly advancing steel fiber distribution characteristics and structural mechanical properties evaluation in tunnel segments.
{"title":"Inductance-based method evaluation of steel fiber distribution and orientation in hybrid-reinforced segment for shield tunnel linings","authors":"Quan Zhang, Xiaohui Zhang, Hule Li, Shunhua Zhou, Naichen Shi, Chao He, Honggui Di","doi":"10.1016/j.ndteint.2025.103610","DOIUrl":"10.1016/j.ndteint.2025.103610","url":null,"abstract":"<div><div>Rebar and steel fiber hybrid reinforced concrete (RC-SFRC) segments are gaining prominence in large-cross-section subway shield tunnel construction due to superior durability and crack resistance. However, conventional methods for evaluating steel fiber distribution and orientation face destructiveness and complexity, limiting large-volume concrete segment quality control applications. This study develops inductance-based techniques to enable nondestructive assessment of fiber distribution and orientation characteristics. On this basis, the research analyzes inductive method measurement-related engineering affecting factors, investigates fiber distribution characteristics and their effect on crack resistance in RC-SFRC segments. Experimental results demonstrate that inductance techniques exhibit robustness and efficiency for steel fiber characterization in tunnel segment applications. RC-SFRC segments' representative specimen dimensions of 50 mm radius for cylindrical and 90 mm edge length for cubic samples effectively reduce fiber content inductance-testing dispersion. Steel fiber distribution and orientation in the RC-SFRC segment show preferential distributions, featuring two significantly thickness-dependent dose distributions while preferentially orienting in the central angle direction, thereby reducing outer arc layer crack resistance capacity. Inductive-based orientation characterization can effectively communicate Barcelona testing fracture surfaces and post-cracking performance, significantly advancing steel fiber distribution characteristics and structural mechanical properties evaluation in tunnel segments.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103610"},"PeriodicalIF":4.5,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we propose an advanced guided wave phased array (PA) ultrasonic imaging technique for improved defect detection in thin plate-like structures, leveraging Vector Coherence Factor (VCF)-weighted Total Focusing Method (TFM). In this approach, the guided wave is transmitted and received, particularly lamb waves, using the full matrix capture (FMC) scanning strategy for long-range inspection. A high-resolution image is obtained by virtually focusing on every point in the region of interest through TFM beamforming, which is weighted with VCF to improve the detectability of the defects in near-field, dead-zone, and far fields. However, in long-range inspections using Lamb waves, employing the FMC-TFM technique reduces the signal-to-noise ratio (SNR) in the received signals and lowers image resolution due to beam spreading and their inherent dispersive nature. Therefore, we implemented the VCF to weight the TFM beamforming process. VCF-TFM utilizes both amplitude and instantaneous phase information by analyzing received signals as complex vectors. Specifically, VCF evaluates coherence by analyzing the received signals as vectors in the complex domain, effectively enhancing phase-consistent defect reflections while suppressing incoherent background noise. The effectiveness of the proposed technique is experimentally validated on long stainless steel plate specimens containing multiple defects located in the near-field, far-field, and dead-zone regions. The results demonstrate that the proposed VCF-TFM approach significantly improves SNR and image resolution compared to conventional amplitude-based TFM techniques, enabling more accurate and reliable defect characterization in thin plate-like structures.
{"title":"Phased array guided wave imaging with Vector Coherence Factor for thin-walled structures","authors":"Kaushal Bachhav , Thulsiram Gantala , Krishnan Balasubramaniam","doi":"10.1016/j.ndteint.2025.103598","DOIUrl":"10.1016/j.ndteint.2025.103598","url":null,"abstract":"<div><div>In this paper, we propose an advanced guided wave phased array (PA) ultrasonic imaging technique for improved defect detection in thin plate-like structures, leveraging Vector Coherence Factor (VCF)-weighted Total Focusing Method (TFM). In this approach, the guided wave is transmitted and received, particularly lamb waves, using the full matrix capture (FMC) scanning strategy for long-range inspection. A high-resolution image is obtained by virtually focusing on every point in the region of interest through TFM beamforming, which is weighted with VCF to improve the detectability of the defects in near-field, dead-zone, and far fields. However, in long-range inspections using Lamb waves, employing the FMC-TFM technique reduces the signal-to-noise ratio (SNR) in the received signals and lowers image resolution due to beam spreading and their inherent dispersive nature. Therefore, we implemented the VCF to weight the TFM beamforming process. VCF-TFM utilizes both amplitude and instantaneous phase information by analyzing received signals as complex vectors. Specifically, VCF evaluates coherence by analyzing the received signals as vectors in the complex domain, effectively enhancing phase-consistent defect reflections while suppressing incoherent background noise. The effectiveness of the proposed technique is experimentally validated on long stainless steel plate specimens containing multiple defects located in the near-field, far-field, and dead-zone regions. The results demonstrate that the proposed VCF-TFM approach significantly improves SNR and image resolution compared to conventional amplitude-based TFM techniques, enabling more accurate and reliable defect characterization in thin plate-like structures.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103598"},"PeriodicalIF":4.5,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-21DOI: 10.1016/j.ndteint.2025.103609
Jacob H. Brody , Prabhakaran Manogharan , Emma E. Peleg , Nathan W. Moore , Alper Erturk
Thermally sprayed coatings are extensively used in the energy and aerospace sectors to protect surfaces against wear, oxidation, corrosion, and for thermal insulation; therefore their characterization is vital to preserving and protecting key infrastructural capabilities. In this study, we conduct experiments to examine the feasibility of using nonlinear ultrasonic/acoustic techniques such as nonlinear resonance acoustic spectroscopy (NRAS) and second harmonic generation (SHG) to characterize thermally sprayed nickel coatings. Nonlinear elastic parameters have been proven to be highly sensitive to microstructural features in materials. This work characterizes the and nonlinearity parameters which are related to the degree of micro-damages (interlamellar gap/void structures) intrinsic to sprayed coatings. In this work, thermally sprayed nickel coatings are sprayed onto stainless steel substrates at two particle sizes (Ni 101 - fine powder and Ni 969 - coarse powder) and spray distances (101.6 and 203.2 mm stand-off distance). The sprayed coatings are separated from their substrates to determine if the nonlinearity parameters can effectively measure microstructural changes in these samples. The nonlinearity parameters measured independently from two different nonlinear ultrasonic/acoustic techniques show an increasing trend with increasing particle sizes and spray distances. Furthermore, NRAS measurements of coatings with and without the substrate indicate that the nonlinearity of thermally sprayed coatings can still be characterized on the thicker substrate. In addition to estimating the nonlinear parameters, porosity, hardness, wave speed and attenuation are also reported. Our results suggest that these nonlinear ultrasonic/acoustic techniques can be potentially used as an inspection and quality control tool for thermal spray coatings.
{"title":"Linear and nonlinear ultrasonic/acoustic characterization of thermally sprayed nickel coatings","authors":"Jacob H. Brody , Prabhakaran Manogharan , Emma E. Peleg , Nathan W. Moore , Alper Erturk","doi":"10.1016/j.ndteint.2025.103609","DOIUrl":"10.1016/j.ndteint.2025.103609","url":null,"abstract":"<div><div>Thermally sprayed coatings are extensively used in the energy and aerospace sectors to protect surfaces against wear, oxidation, corrosion, and for thermal insulation; therefore their characterization is vital to preserving and protecting key infrastructural capabilities. In this study, we conduct experiments to examine the feasibility of using nonlinear ultrasonic/acoustic techniques such as nonlinear resonance acoustic spectroscopy (NRAS) and second harmonic generation (SHG) to characterize thermally sprayed nickel coatings. Nonlinear elastic parameters have been proven to be highly sensitive to microstructural features in materials. This work characterizes the <span><math><mi>α</mi></math></span> and <span><math><mi>β</mi></math></span> nonlinearity parameters which are related to the degree of micro-damages (interlamellar gap/void structures) intrinsic to sprayed coatings. In this work, thermally sprayed nickel coatings are sprayed onto stainless steel substrates at two particle sizes (Ni 101 - fine powder and Ni 969 - coarse powder) and spray distances (101.6 and 203.2 mm stand-off distance). The sprayed coatings are separated from their substrates to determine if the nonlinearity parameters can effectively measure microstructural changes in these samples. The nonlinearity parameters measured independently from two different nonlinear ultrasonic/acoustic techniques show an increasing trend with increasing particle sizes and spray distances. Furthermore, NRAS measurements of coatings with and without the substrate indicate that the nonlinearity of thermally sprayed coatings can still be characterized on the thicker substrate. In addition to estimating the nonlinear parameters, porosity, hardness, wave speed and attenuation are also reported. Our results suggest that these nonlinear ultrasonic/acoustic techniques can be potentially used as an inspection and quality control tool for thermal spray coatings.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103609"},"PeriodicalIF":4.5,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-21DOI: 10.1016/j.ndteint.2025.103599
Geng Yang , Haoran Li , Bin Gao , Xiaolong Lu , Junhong Qi , Dong Liu , Guiyun Tian , Xiaojie Xue , Xingcai Liu
Lift-off variability poses a significant challenge in electromagnetic thermography (ET) for detecting surface defects on rails, particularly under dynamic scanning conditions. To overcome this limitation, we propose a lift-off tolerant ET system based on a multiporous-cascaded excitation coil. This coil design enhances electromagnetic excitation and expands the effective heating footprint on the rail surface. Finite element simulations under various lift-off distances evaluate the coil's thermal response and excitation coverage. Compared to a conventional dual-turn elliptical coil, the proposed structure demonstrates superior heating intensity and spatial uniformity at large lift-off distances. Experimental validation at a scanning speed of 1 m/s with a 30 mm lift-off confirms the system's capability to detect multiple defect types with enhanced thermal contrast and signal robustness. These results validate the practical feasibility of the proposed system for dynamic rail inspection under large lift-off conditions.
{"title":"Multiporous-cascaded coil based high lift-off and dynamic electromagnetic thermography of rail defects inspection","authors":"Geng Yang , Haoran Li , Bin Gao , Xiaolong Lu , Junhong Qi , Dong Liu , Guiyun Tian , Xiaojie Xue , Xingcai Liu","doi":"10.1016/j.ndteint.2025.103599","DOIUrl":"10.1016/j.ndteint.2025.103599","url":null,"abstract":"<div><div>Lift-off variability poses a significant challenge in electromagnetic thermography (ET) for detecting surface defects on rails, particularly under dynamic scanning conditions. To overcome this limitation, we propose a lift-off tolerant ET system based on a multiporous-cascaded excitation coil. This coil design enhances electromagnetic excitation and expands the effective heating footprint on the rail surface. Finite element simulations under various lift-off distances evaluate the coil's thermal response and excitation coverage. Compared to a conventional dual-turn elliptical coil, the proposed structure demonstrates superior heating intensity and spatial uniformity at large lift-off distances. Experimental validation at a scanning speed of 1 m/s with a 30 mm lift-off confirms the system's capability to detect multiple defect types with enhanced thermal contrast and signal robustness. These results validate the practical feasibility of the proposed system for dynamic rail inspection under large lift-off conditions.</div></div>","PeriodicalId":18868,"journal":{"name":"Ndt & E International","volume":"159 ","pages":"Article 103599"},"PeriodicalIF":4.5,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号