Rail squats are a form of near surface rolling contact fatigue damage found in rail heads. Currently, the most popular method to detect the rail squats is utilizing ultrasonic techniques to determine their presence an...Rail squats are a form of near surface rolling contact fatigue damage found in rail heads. Currently, the most popular method to detect the rail squats is utilizing ultrasonic techniques to determine their presence and measure their depths. This technique needs to be direct contact between the probe and the rail head, with a coupling fluid in at the interface. Other weaknesses of these ultrasonic techniques include false detections as well as missed detections. Infrared thermography is a relatively new non-destructive inspection technique used for a wide range of applications but is not used for rail squat detection. Lock-in thermography is a non-destructive inspection technique that can be used for the detection of near surface defects. It utilizes an infrared camera to detect the thermal waves and then produces a thermal image, which displays the local thermal wave variation in phase or amplitude. In inhomogeneous materials, the amplitude and phase of the thermal wave carries information related to both the local thermal properties and the nature of the structure being inspected. This comparison is then used to determine the phase angle difference (Δf) between the input and the thermal response of the object. The aim of this paper is to determine whether lock-in thermography can be used to firstly locate squats in rails, and secondly measure their depths. It has demonstrated the feasibility for using such a technique in generating thermal responses that could be adequately utilized for the purpose of defect characterization.展开更多
The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing ...The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing industry.A large composite sample,with Polytetrafluoroethylene(PTFE)artificial defects,replicating a side-wall section of a new rail carbody,was manufactured and inspected for surface and subsurface defects in this research.The sample,characterized by its large thickness,consists of a monolithic Carbon Fibre Reinforced Polymers(CFRP)component(20mm thickness)and a CFRP-PET foam-CFRP sandwich(40mm total thickness)component fused together.The main challenge of the inspection procedure was to apply reflection mode thermography and detect defects in the entire thickness of the sample that exhibits both low emissivity and thermal insulating properties,especially at the sandwich sections of the sample.The paper explored thermography procedures that would be able to detect large numbers of defects under one single acquisition and would be applied under an automated inspection process leading to the detection of defects only up to 5mm in the CFRP sections of the sample while no defects were able to be detected at the back skin of the sample.展开更多
Civil infrastructure is continuously subject to aging and deterioration due to multiple factors,which lead to a decline in performance and impact structural health.Accumulated damage on structures increases operationa...Civil infrastructure is continuously subject to aging and deterioration due to multiple factors,which lead to a decline in performance and impact structural health.Accumulated damage on structures increases operational costs and poses significant risks to public safety.Effective maintenance,repair,and rehabilitation strategies are needed to ensure civil infrastructure’s overall safety and reliability.Non-Destructive Evaluation(NDE)methods are utilized to assess latent damage and provide decision-makers with real-time information for mitigating hazards.Within the last decade,there has been a significant increase in the research and development of innovative NDE techniques to improve data processing and promote efficient and accurate infrastructure assessment.This paper aims to review one of those methods,namely,Infrared Thermography(IRT),and its applications in civil infrastructure.A comprehensive review is presented by investigating numerous journal articles,research papers,and technical reports describing numerous IRT applications for bridges,buildings,and general civil structures made from different materials.The capability of IRT to identify and pinpoint anomalies,typically in the early stages of degradation,has excellent potential to improve the safety and shore up the dependability of civil infrastructures while reducing expenses tied to maintenance and rehabilitation.Furthermore,the non-invasive nature of IRT is beneficial in mitigating disturbances and downtime that may occur during various inspection procedures.It is highlighted that IRT is a highly versatile and effective tool for infrastructure condition assessment.With further advancement and fine-tuning of the available techniques,it is likely that IRT will continue to gain significant popularity in maintaining and monitoring civil infrastructure.展开更多
Objective:To evaluate the use of infrared thermography technology for objective and quantitative syndrome differentiation and treatment in traditional Chinese medicine(TCM),specifically in patients with Chaihu Guizhi ...Objective:To evaluate the use of infrared thermography technology for objective and quantitative syndrome differentiation and treatment in traditional Chinese medicine(TCM),specifically in patients with Chaihu Guizhi Ganjiang Decoction syndrome.Methods:Data were collected from over 100 patients diagnosed with Chaihu Guizhi Ganjiang Decoction syndrome at Professor Li Leyu’s endocrinology clinic,Zhongshan Hospital of Traditional Chinese Medicine,Guangdong Province,between April 2021 and April 2022.Body surface temperature data were obtained using the MTI-EXPRO-2013-B infrared thermography system.Principal component analysis(PCA)was applied to differentiate temperature distribution characteristics between genders,and a neural network prediction model was constructed for syndrome diagnosis.Results:Infrared thermography effectively captured surface temperature characteristics of patients with Chaihu Guizhi Ganjiang Decoction syndrome.PCA identified one principal component with a variance explanation rate of 73.953%for females and two principal components with a cumulative variance explanation rate of 77.627%for males.The neural network model demonstrated high predictive performance,with an area under the ROC curve of 0.9743 for the training set and 0.9889 for the validation set.Sensitivity was 1,specificity 0.8636,precision 0.8846,accuracy 0.9333,and the F1 score 0.9388.Conclusion:Infrared thermography provides an innovative,objective,and quantitative method for syndrome differentiation and treatment in TCM.It represents a significant advancement in transitioning from traditional empirical approaches to modern,visualized,and precise diagnosis and treatment.This study underscores the potential of integrating advanced technologies in TCM for enhanced clinical application and modernization.展开更多
Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechan...Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generationwas discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based ontheevolution of the temperatureand hotspot zone on the specimen surfaceduring fatigue tests. The presented results show that infrared thermography can not onlyquicklypredict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventionalS-Nexperimental results. The evolution of the temperatureand hotspot zone on the specimen surface can be an effectivefatigue damage indicatorfor effectiveevaluationof magnesium alloy electron beam welded joint.展开更多
The method of infrared thermography to predict the temperature of the sulfide ores has a large error. To solve this problem, the temperature of the sulfide ores is measured by thermal infrared imager and recording the...The method of infrared thermography to predict the temperature of the sulfide ores has a large error. To solve this problem, the temperature of the sulfide ores is measured by thermal infrared imager and recording thermometric instrument contrastively. The main factors, including emissivity, distance, angle and dust concentration that affect the temperature measurement precision, are analyzed. The regression equations about the individual factors and comprehensive factors are obtained by analyzing test data. The application of the regression equations improves the precision of the thermal infrared imager. The geometric information lost in traditional infrared thermometry is determined by visualization grid method and interpolation method, the relationship between the infrared imager and geometry information is established. The geometry location can be measured exactly.展开更多
文摘Rail squats are a form of near surface rolling contact fatigue damage found in rail heads. Currently, the most popular method to detect the rail squats is utilizing ultrasonic techniques to determine their presence and measure their depths. This technique needs to be direct contact between the probe and the rail head, with a coupling fluid in at the interface. Other weaknesses of these ultrasonic techniques include false detections as well as missed detections. Infrared thermography is a relatively new non-destructive inspection technique used for a wide range of applications but is not used for rail squat detection. Lock-in thermography is a non-destructive inspection technique that can be used for the detection of near surface defects. It utilizes an infrared camera to detect the thermal waves and then produces a thermal image, which displays the local thermal wave variation in phase or amplitude. In inhomogeneous materials, the amplitude and phase of the thermal wave carries information related to both the local thermal properties and the nature of the structure being inspected. This comparison is then used to determine the phase angle difference (Δf) between the input and the thermal response of the object. The aim of this paper is to determine whether lock-in thermography can be used to firstly locate squats in rails, and secondly measure their depths. It has demonstrated the feasibility for using such a technique in generating thermal responses that could be adequately utilized for the purpose of defect characterization.
文摘The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing industry.A large composite sample,with Polytetrafluoroethylene(PTFE)artificial defects,replicating a side-wall section of a new rail carbody,was manufactured and inspected for surface and subsurface defects in this research.The sample,characterized by its large thickness,consists of a monolithic Carbon Fibre Reinforced Polymers(CFRP)component(20mm thickness)and a CFRP-PET foam-CFRP sandwich(40mm total thickness)component fused together.The main challenge of the inspection procedure was to apply reflection mode thermography and detect defects in the entire thickness of the sample that exhibits both low emissivity and thermal insulating properties,especially at the sandwich sections of the sample.The paper explored thermography procedures that would be able to detect large numbers of defects under one single acquisition and would be applied under an automated inspection process leading to the detection of defects only up to 5mm in the CFRP sections of the sample while no defects were able to be detected at the back skin of the sample.
文摘Civil infrastructure is continuously subject to aging and deterioration due to multiple factors,which lead to a decline in performance and impact structural health.Accumulated damage on structures increases operational costs and poses significant risks to public safety.Effective maintenance,repair,and rehabilitation strategies are needed to ensure civil infrastructure’s overall safety and reliability.Non-Destructive Evaluation(NDE)methods are utilized to assess latent damage and provide decision-makers with real-time information for mitigating hazards.Within the last decade,there has been a significant increase in the research and development of innovative NDE techniques to improve data processing and promote efficient and accurate infrastructure assessment.This paper aims to review one of those methods,namely,Infrared Thermography(IRT),and its applications in civil infrastructure.A comprehensive review is presented by investigating numerous journal articles,research papers,and technical reports describing numerous IRT applications for bridges,buildings,and general civil structures made from different materials.The capability of IRT to identify and pinpoint anomalies,typically in the early stages of degradation,has excellent potential to improve the safety and shore up the dependability of civil infrastructures while reducing expenses tied to maintenance and rehabilitation.Furthermore,the non-invasive nature of IRT is beneficial in mitigating disturbances and downtime that may occur during various inspection procedures.It is highlighted that IRT is a highly versatile and effective tool for infrastructure condition assessment.With further advancement and fine-tuning of the available techniques,it is likely that IRT will continue to gain significant popularity in maintaining and monitoring civil infrastructure.
基金Zhongshan Science and Technology Bureau Project“The Application of Infrared Thermography in the Syndrome Differentiation of Chaihu Guizhi Ganjiang Decoction”(Project No.2021B1066)Zhongshan Science and Technology Bureau Project“Exploring the Diagnostic Approach of the TCM Syndrome Type‘Chaihu Guizhi Ganjiang Decoction’Based on Infrared Thermal Imaging Systems and Digital Modeling Methods of Ancient and Modern Literature”(Project No.2022B1131)。
文摘Objective:To evaluate the use of infrared thermography technology for objective and quantitative syndrome differentiation and treatment in traditional Chinese medicine(TCM),specifically in patients with Chaihu Guizhi Ganjiang Decoction syndrome.Methods:Data were collected from over 100 patients diagnosed with Chaihu Guizhi Ganjiang Decoction syndrome at Professor Li Leyu’s endocrinology clinic,Zhongshan Hospital of Traditional Chinese Medicine,Guangdong Province,between April 2021 and April 2022.Body surface temperature data were obtained using the MTI-EXPRO-2013-B infrared thermography system.Principal component analysis(PCA)was applied to differentiate temperature distribution characteristics between genders,and a neural network prediction model was constructed for syndrome diagnosis.Results:Infrared thermography effectively captured surface temperature characteristics of patients with Chaihu Guizhi Ganjiang Decoction syndrome.PCA identified one principal component with a variance explanation rate of 73.953%for females and two principal components with a cumulative variance explanation rate of 77.627%for males.The neural network model demonstrated high predictive performance,with an area under the ROC curve of 0.9743 for the training set and 0.9889 for the validation set.Sensitivity was 1,specificity 0.8636,precision 0.8846,accuracy 0.9333,and the F1 score 0.9388.Conclusion:Infrared thermography provides an innovative,objective,and quantitative method for syndrome differentiation and treatment in TCM.It represents a significant advancement in transitioning from traditional empirical approaches to modern,visualized,and precise diagnosis and treatment.This study underscores the potential of integrating advanced technologies in TCM for enhanced clinical application and modernization.
基金Project(51305292)supported by the National Natural Science Foundation of ChinaProject(20105429001)supported by the National Aeronautical Science Foundation of China
文摘Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generationwas discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based ontheevolution of the temperatureand hotspot zone on the specimen surfaceduring fatigue tests. The presented results show that infrared thermography can not onlyquicklypredict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventionalS-Nexperimental results. The evolution of the temperatureand hotspot zone on the specimen surface can be an effectivefatigue damage indicatorfor effectiveevaluationof magnesium alloy electron beam welded joint.
基金Project (51074181) supported by the National Natural Science Foundation of ChinaProject (2010ssxt241) supported by Precious Dissertation Innovation Foundation of Central South University, China
文摘The method of infrared thermography to predict the temperature of the sulfide ores has a large error. To solve this problem, the temperature of the sulfide ores is measured by thermal infrared imager and recording thermometric instrument contrastively. The main factors, including emissivity, distance, angle and dust concentration that affect the temperature measurement precision, are analyzed. The regression equations about the individual factors and comprehensive factors are obtained by analyzing test data. The application of the regression equations improves the precision of the thermal infrared imager. The geometric information lost in traditional infrared thermometry is determined by visualization grid method and interpolation method, the relationship between the infrared imager and geometry information is established. The geometry location can be measured exactly.
