This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview ...This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.展开更多
Phase aberration correction for medical ultrasound systems has attracted a great deal of attention. Since phased array techniques are now widely employed for industrial non-destructive testing （NDT） applications in ...Phase aberration correction for medical ultrasound systems has attracted a great deal of attention. Since phased array techniques are now widely employed for industrial non-destructive testing （NDT） applications in various fields, the problem of phase aberrations in the process of NDT testing is considered. The technique of cross-covariance for phase aberration correction is presented. The performance of the technique for phase aberration correction is tested by means of echo signals obtained in practical non-destructive testing experiment. The results show that the technique has the better accuracy of phase correction.展开更多
Because the UT （ultrasonic testing） flexible probe technology may be an appropriate answer to examine components with uneven surface, AREVA has developed an industrial application of the CEA＇s （French Atomic Energ...Because the UT （ultrasonic testing） flexible probe technology may be an appropriate answer to examine components with uneven surface, AREVA has developed an industrial application of the CEA＇s （French Atomic Energy and Alternative Energies） flexible phased arrays sensors. As a ＂first of a kind＂ project, the challenges faced were significant, including developing a phased array smart probe suitable for industrial use on rather simple but large scale geometries, permitting UT propagation within a constraining media structure and then targeting a qualification according to ENIQ （European Network for Inspection Qualification） methodology. A prototype flexible probe, designed for UT validation, and final flexible linear array probes permitting the UT behavior （as, e.g., detection and sizing from diffraction type echoes） to be maintained on wavy coupling surfaces, have been manufactured. These probes include a profilemeter with optical sensors control and a specifically designed coupling circuit （avoiding probe housing tightness issues）. Qualification has been performed using open test blocks, （where known ＂defects＂ exist, for procedure qualification）, and blind test blocks, （where ＂defects＂ are unknown, for qualification of testing personnel）. One open test bloc was customized to represent a ＂real＂ surface condition, with gaps up to 2.5 mm under the regular rigid probes. AREVAI/BGSI in Germany was selected to lead the project, with assistance in development and manufacturing sub-contracted to ＂CEA/LIST＂ laboratory, and the companies ＂IMASONIC＂ and ＂M2M＂. This paper describes the development of these probes and explains a few features （ENIQ qualification objectives fulfilled, UT data acquired on actual perturbed surface） that made their industrial implementation successful.展开更多
Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection ...Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.展开更多
Non-destructive testing is a kind of will not cause damage to the detection object and influence of detection technology, mainly using the material or equipment problems often in light, thermal, magnetic reaction chan...Non-destructive testing is a kind of will not cause damage to the detection object and influence of detection technology, mainly using the material or equipment problems often in light, thermal, magnetic reaction changes for the abnormalities and defects and the existing problems of the detection results. This paper firstly introduces the characteristics of the NDT technology, discusses the main problems in the construction engineering testing and analyzes the practical application of the technology.展开更多
At present, with the continuous development of various technologies, in the process of water conservancy project quality inspection, more attention should be paid to fully improve various technologies to better guaran...At present, with the continuous development of various technologies, in the process of water conservancy project quality inspection, more attention should be paid to fully improve various technologies to better guarantee the quality inspection effect. Relevant personnel should make full use of the advantages and characteristics of non-destructive testing technology, and further strengthen the optimization of each link of quality testing. Non-destructive testing technology has received relatively high attention from various industries in the society. The application of non-destructive testing technology in the quality testing process of water conservancy projects can better guarantee the quality of the projects themselves, but also reduce the adverse effects of the projects themselves, making non-destructive testing technology of higher application value. This paper will mainly discuss the relevant contents of non-destructive testing technology.展开更多
In recent years, the development process of China's petrochemical industry has been accelerating, and the demand and standard for each component are also gradually improving, which has promoted the development and...In recent years, the development process of China's petrochemical industry has been accelerating, and the demand and standard for each component are also gradually improving, which has promoted the development and progress of China's petrochemical industry to a certain extent. In order to improve the construction level of petrochemical engineering, it is also necessary to apply digital non-destructive testing technology of welds to ensure the safety of oil and gas pipeline projects.展开更多
The application of non-destructive testing technology in pressure pipeline inspection is based on the characteristics of matter light, sound, electricity and magnetism, without affecting or damaging the service perfor...The application of non-destructive testing technology in pressure pipeline inspection is based on the characteristics of matter light, sound, electricity and magnetism, without affecting or damaging the service performance of the tested object, to understand whether it is uniform and has defects, and to obtain information such as location, nature, quantity and defect size. The advantage of this technology is that it is non-destructive and has become an indispensable testing tool in industrial development. At the same time, with the increasing demand for pressure pipes and the extension of overhaul period, higher requirements are put forward for testing technology. Therefore, it is necessary to further intensify the research and development of testing technology for pressure pipes.展开更多
With the continuous development of our society, the application of ultrasonic non-destructive testing technology has become more and more in-depth. At present, ultrasonic non-destructive testing technology has been wi...With the continuous development of our society, the application of ultrasonic non-destructive testing technology has become more and more in-depth. At present, ultrasonic non-destructive testing technology has been widely used in hydraulic structural concrete, and has achieved good application results. Compared with other detection technologies, ultrasonic non-destructive testing technology has the characteristics of strong adaptability and high detection sensitivity. So in the actual detection process, the work efficiency is relatively high, and it will not pose a threat to the life safety of the staff. Based on this, this paper explores the factors affecting the application of ultrasonic non-destructive testing technology and the corresponding countermeasures by analyzing the current development status and related overview of ultrasonic non-destructive testing technology.展开更多
Concrete is one of the most important elements in building construction.However,concrete used in construction is susceptible to damage due to corrosion.The influence of corrosive substances causes changes in the reinf...Concrete is one of the most important elements in building construction.However,concrete used in construction is susceptible to damage due to corrosion.The influence of corrosive substances causes changes in the reinforcing steel and affects the strength of the structure.The repair method is one approach to overcome this problem.This research aims to determine the effect of grouting and jacketing repairs on corroded concrete.The concrete used has dimensions of 15 cm×15 cm×60 cm with planned corrosion variations of 50%,60%,and 70%.The test objects were tested using the Non-Destructive Testing(NDT)method using Ultrasonic Pulse Velocity(UPV).The test results show that the average speed of normal concrete is 5070 m/s,while the lowest average speed is 3070 m/s on the 70%planned corrosion test object.The test object was then given a load of 1600 kgf.At this stage,there is a decrease in speed and wave shape with the lowest average speed obtained at 2753 m/s.The repair method is an effort to restore concrete performance by using grouting and jacketing.Grouting is done by injecting mortar material into it.Jacketing involves adding thickness to the existing concrete layer with additional layers of concrete.After improvements were made,there was an improvement in the UPV test,with a peak speed value of 4910 m/s.Repairing concrete by filling cracks can improve concrete continuity and reduce waveform distortion,thereby increasing wave propagation speed.展开更多
A research about the ultrasonic phased array imaging principle from A-scan signal to B-scan image for non-destructive testing （NDT） was conducted in this paper, the ultrasonic phased array inspection imaging system ...A research about the ultrasonic phased array imaging principle from A-scan signal to B-scan image for non-destructive testing （NDT） was conducted in this paper, the ultrasonic phased array inspection imaging system used in industrial field was developed and the experiment was performed on the steel testing block by the system with 64 elements, 5 MHz phased array transducer. Experimental results show that the flaws could be accurately detected and the flaws size could be estimated from the B-scan images, and the B-scan images could clearly show the location of the flaws, but the quality of B-scan images needs to be enhanced by digital signal processing and controlling dynamic focusing for improving the image resolution.展开更多
The laser powder bed fusion(L-PBF)method of additive manufacturing(AM)is increasingly used in various industrial manufacturing fields due to its high material utilization and design freedom of parts.However,the parts ...The laser powder bed fusion(L-PBF)method of additive manufacturing(AM)is increasingly used in various industrial manufacturing fields due to its high material utilization and design freedom of parts.However,the parts produced by L-PBF usually contain such defects as crack and porosity because of the technological characteristics of L-PBF,which affect the quality of the product.Laser ultrasonic testing(LUT)is a potential technology for on-line testing of the L-PBF process.It is a non-contact and non-destructive approach based on signals from abundant waveforms with a wide frequency-band.In this study,a method of LUT for on-line inspection of L-PBF process was proposed,and a system of LUT was established approaching the actual environment of on-line detection to evaluate the method applicability for defects detection of L-PBF parts.The detection results of near-surface defects in L-PBF 316L stainless steel parts show that the crack-type defects with a sub-millimeter level within 0.5 mm depth can be identified,and accordingly,the positions and dimensions information can be acquired.The results were verified by X-ray computed tomography,which indicates that the present method exhibits great potential for on-line inspection of AM processes.展开更多
Basic magnesium sulfate cement coral aggregate concrete(MCAC)is a new type of concrete consisting of basic magnesium sulfate cement,coarse coral aggregate,coral reef sand and seawater.The rebound hammer(RH),the ultras...Basic magnesium sulfate cement coral aggregate concrete(MCAC)is a new type of concrete consisting of basic magnesium sulfate cement,coarse coral aggregate,coral reef sand and seawater.The rebound hammer(RH),the ultrasonic pulse velocity(UPV)and the compressive strength(fcu)tests of 14 sets of cube specimens of the MCAC after 28 d of aging were conducted.The impact of the content and length of sisal fiber on the relationship between the fcu-RH and the fcu-UPV was determined.A mathematical model was established to predict the strength of the MCAC using the UPV,RH,and comprehensive UPV/RH methods and to obtain the curves of test strength.The applicability of the test strength curves of ordinary portland concrete(OPC),light-weight aggregate concrete(LAC),and coral aggregate concrete(CAC)to MCAC was assessed.The results showed that the test strength curves of OPC,LAC and CAC were inappropriate to determine the strength of MCAC using non-destructive method.The relative standard error of the curves of test strength of the RH method and the comprehensive method met the specifications,whereas that of the UPV method did not.展开更多
Ultrasonic testing is a very important non-destructive method for testing components for safety of nuclear power plants and other security and delicate parts in other industries. Nowadays, thanks to the development of...Ultrasonic testing is a very important non-destructive method for testing components for safety of nuclear power plants and other security and delicate parts in other industries. Nowadays, thanks to the development of computer technology, it is possible to simulate processes which occur during ultrasonic testing. That is why numerical simulations are becoming an integral part of non-destructive testing. Simulations are used to determine parameters of ultrasonic examination, especially parameters of probes and scan plan and also in the analysis of results. They are used in such cases, when it is necessary to verify applicability of probes and methods. This verification could be provided on the weld and test block which are not manufactured. It could be also provided on defects, which are not manufactured in test block, but their presence is possible in given weld joint. Simulations are very useful for verifying the propagation of ultrasonic signal in given area (e.g. weld area). If movement of probe is limited, possibility of whole volume scan should be verified.展开更多
Nondestructive testing technology is a common technology in the building quality testing work to complete the detection through energy body penetration. The interior of the building can be inspected without much affec...Nondestructive testing technology is a common technology in the building quality testing work to complete the detection through energy body penetration. The interior of the building can be inspected without much affecting or damaging the building. In practice, the nondestructive detection technology is more efficient and has more accurate identification results. Therefore, the construction enterprises should increase the research and application of nondestructive testing technology to improve the level of construction technology. This paper also analyzes the application of nondestructive testing technology in construction engineering testing.展开更多
The crack initiation stress threshold is widely used in excavation industries as rock spalling strength when designing deep underground structures to avoid unwanted brittle failures.While various strain-based methods ...The crack initiation stress threshold is widely used in excavation industries as rock spalling strength when designing deep underground structures to avoid unwanted brittle failures.While various strain-based methods have been developed for the estimation of this critical design parameter,such methods are destructive and often requires subjective interpretations of the stress–strain curves,particularly in rocks with pre-existing microcracks or high porosity.This study explore the applicability of non-destructive ultrasonic through-transmission methods for determining rock damage levels by assessing the changes in transmitted signal characteristics during loading.The change in velocity,amplitude,dominant frequency,and root-mean-square voltage are investigated with four different rock types including marble,sandstone,granite,and basalt under various stress levels.Results suggest the rate of signal variations can be reliably used to estimate crack closure and crack initiation stress levels across the tested rocks before failure.Comparison of the results between the conventional techniques and the new proposed methods based on ultrasonic monitoring are further discussed.展开更多
Wall thickness is always a key index for boiler tube inspection in power plant,in order to improve the inspection efficiency and accuracy,a new method fusing the magnetic and ultrasonic technique was proposed.The magn...Wall thickness is always a key index for boiler tube inspection in power plant,in order to improve the inspection efficiency and accuracy,a new method fusing the magnetic and ultrasonic technique was proposed.The magnetic technique was used to do full inspection and locate the flaws,and the ultrasonic was employed to implement further quantitative inspection accu- rately.After comparing the precision of the polynomial,exponential and logarithmic function,the polynomial model was selected to fit the relations between the wall thickness and the peak value of magnetic signals,and the data measured by ultrasonic thickness meter was used to calibrate the model parameters online,the defect depth can be sized quickly.The experimental results demon- grate that the model used in this system has better accuracy than the statistics relation model clearly,and it is also suitable for defect evaluation real-time.Moreover,it is unnecessary to have much more experimental data for the curve fitting technology,so it has better practicability than the other methods.展开更多
To overcome the inherent limits of traditional single wave imaging for nondestructive testing,the multi-wave focusing and imaging method is thoroughly studied.This method makes the compressional waves and shear waves ...To overcome the inherent limits of traditional single wave imaging for nondestructive testing,the multi-wave focusing and imaging method is thoroughly studied.This method makes the compressional waves and shear waves focused in both emission and reception processes,which strengthens the focusing energy and improves the signal-to-noise ratio of received signals.A numerical model is developed to study the characteristics of a multi-wave focusing field.It is shown that the element width approaching 0.8 wavelengths of shear waves can keep a balance between the radiation energy of two waves,which can achieve a desirable multi-wave focusing performance.And an experiment using different imaging methods for a linear phased array is performed.It can be concluded that due to the combination of the propagation and reflection characteristics of two waves,the multi-wave focusing and imaging method can significantly improve the imaging distinguishability of defects and expand the available sweeping range to a sector of-650 to 65°.展开更多
Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetra...Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetration, well direction, high sensitivity, low cost, and harmless to people and material. The technologies of the computer, NC (Numerical control), precision mechanism, signal analysis and processing were integrated in the testing system. The system includes a PC, system software, ultrasonic data acquisition card, stepper motor drive card and five-axis precision mechanical device, etc. The software was developed using WIN98-based VC++. According to CAD data of the parts and interpolation methods, the scanning programs can be programmed. The five-axis scanning system is driven by the CNC(computer numerical control) system to control the attitude of ultrasonic probes. The system’s automatic scanning for complex surface parts, real-time acquiring ultrasonic data and automatic identifying flaw signal have been realized. This system can be used not only for testing complex surface parts, but for testing random curve parts. With fast testing speed, high sensitivity, high testing precision and high reliability, the system has a wide adaptability.展开更多
The non-destructive testing of brazed joint in honeycomb structure with thin panel （ thickness ： 0. 2 mm） was studied by ultrasonic C-scan method. Samples with different types of artificial defect were designed; th...The non-destructive testing of brazed joint in honeycomb structure with thin panel （ thickness ： 0. 2 mm） was studied by ultrasonic C-scan method. Samples with different types of artificial defect were designed; the characteristic signal and the main parameters of the test were determined by the pre-experiment, and then parameters were optimized by orthogonal design, finally the optimum process was verified by a single panel sample. The multiple reflection echoes were chosen as the characteristic signal. The optimal C-scan results were achieved when the 20 MHz focus probe was used, and the pass band range for received signal were selected as 8 - 17. 5 MHz. The defects such as incomplete penetration and core damage can be detected with ultrasonic C-scan, and the detection accuracy can reach to 1 ram.展开更多
文摘This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.
基金National Natural Science Foundation of China(No.61201412)Ntural Science Foundation of Shanxi Province(No.2012021011-5)
文摘Phase aberration correction for medical ultrasound systems has attracted a great deal of attention. Since phased array techniques are now widely employed for industrial non-destructive testing （NDT） applications in various fields, the problem of phase aberrations in the process of NDT testing is considered. The technique of cross-covariance for phase aberration correction is presented. The performance of the technique for phase aberration correction is tested by means of echo signals obtained in practical non-destructive testing experiment. The results show that the technique has the better accuracy of phase correction.
文摘Because the UT （ultrasonic testing） flexible probe technology may be an appropriate answer to examine components with uneven surface, AREVA has developed an industrial application of the CEA＇s （French Atomic Energy and Alternative Energies） flexible phased arrays sensors. As a ＂first of a kind＂ project, the challenges faced were significant, including developing a phased array smart probe suitable for industrial use on rather simple but large scale geometries, permitting UT propagation within a constraining media structure and then targeting a qualification according to ENIQ （European Network for Inspection Qualification） methodology. A prototype flexible probe, designed for UT validation, and final flexible linear array probes permitting the UT behavior （as, e.g., detection and sizing from diffraction type echoes） to be maintained on wavy coupling surfaces, have been manufactured. These probes include a profilemeter with optical sensors control and a specifically designed coupling circuit （avoiding probe housing tightness issues）. Qualification has been performed using open test blocks, （where known ＂defects＂ exist, for procedure qualification）, and blind test blocks, （where ＂defects＂ are unknown, for qualification of testing personnel）. One open test bloc was customized to represent a ＂real＂ surface condition, with gaps up to 2.5 mm under the regular rigid probes. AREVAI/BGSI in Germany was selected to lead the project, with assistance in development and manufacturing sub-contracted to ＂CEA/LIST＂ laboratory, and the companies ＂IMASONIC＂ and ＂M2M＂. This paper describes the development of these probes and explains a few features （ENIQ qualification objectives fulfilled, UT data acquired on actual perturbed surface） that made their industrial implementation successful.
文摘Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.
文摘Non-destructive testing is a kind of will not cause damage to the detection object and influence of detection technology, mainly using the material or equipment problems often in light, thermal, magnetic reaction changes for the abnormalities and defects and the existing problems of the detection results. This paper firstly introduces the characteristics of the NDT technology, discusses the main problems in the construction engineering testing and analyzes the practical application of the technology.
文摘At present, with the continuous development of various technologies, in the process of water conservancy project quality inspection, more attention should be paid to fully improve various technologies to better guarantee the quality inspection effect. Relevant personnel should make full use of the advantages and characteristics of non-destructive testing technology, and further strengthen the optimization of each link of quality testing. Non-destructive testing technology has received relatively high attention from various industries in the society. The application of non-destructive testing technology in the quality testing process of water conservancy projects can better guarantee the quality of the projects themselves, but also reduce the adverse effects of the projects themselves, making non-destructive testing technology of higher application value. This paper will mainly discuss the relevant contents of non-destructive testing technology.
文摘In recent years, the development process of China's petrochemical industry has been accelerating, and the demand and standard for each component are also gradually improving, which has promoted the development and progress of China's petrochemical industry to a certain extent. In order to improve the construction level of petrochemical engineering, it is also necessary to apply digital non-destructive testing technology of welds to ensure the safety of oil and gas pipeline projects.
文摘The application of non-destructive testing technology in pressure pipeline inspection is based on the characteristics of matter light, sound, electricity and magnetism, without affecting or damaging the service performance of the tested object, to understand whether it is uniform and has defects, and to obtain information such as location, nature, quantity and defect size. The advantage of this technology is that it is non-destructive and has become an indispensable testing tool in industrial development. At the same time, with the increasing demand for pressure pipes and the extension of overhaul period, higher requirements are put forward for testing technology. Therefore, it is necessary to further intensify the research and development of testing technology for pressure pipes.
文摘With the continuous development of our society, the application of ultrasonic non-destructive testing technology has become more and more in-depth. At present, ultrasonic non-destructive testing technology has been widely used in hydraulic structural concrete, and has achieved good application results. Compared with other detection technologies, ultrasonic non-destructive testing technology has the characteristics of strong adaptability and high detection sensitivity. So in the actual detection process, the work efficiency is relatively high, and it will not pose a threat to the life safety of the staff. Based on this, this paper explores the factors affecting the application of ultrasonic non-destructive testing technology and the corresponding countermeasures by analyzing the current development status and related overview of ultrasonic non-destructive testing technology.
基金supported by the Ministry of Education,Culture,Research,and Technology(Indonesia),Grant number 107/E5/PG.02.00.PL/2024,AZ.
文摘Concrete is one of the most important elements in building construction.However,concrete used in construction is susceptible to damage due to corrosion.The influence of corrosive substances causes changes in the reinforcing steel and affects the strength of the structure.The repair method is one approach to overcome this problem.This research aims to determine the effect of grouting and jacketing repairs on corroded concrete.The concrete used has dimensions of 15 cm×15 cm×60 cm with planned corrosion variations of 50%,60%,and 70%.The test objects were tested using the Non-Destructive Testing(NDT)method using Ultrasonic Pulse Velocity(UPV).The test results show that the average speed of normal concrete is 5070 m/s,while the lowest average speed is 3070 m/s on the 70%planned corrosion test object.The test object was then given a load of 1600 kgf.At this stage,there is a decrease in speed and wave shape with the lowest average speed obtained at 2753 m/s.The repair method is an effort to restore concrete performance by using grouting and jacketing.Grouting is done by injecting mortar material into it.Jacketing involves adding thickness to the existing concrete layer with additional layers of concrete.After improvements were made,there was an improvement in the UPV test,with a peak speed value of 4910 m/s.Repairing concrete by filling cracks can improve concrete continuity and reduce waveform distortion,thereby increasing wave propagation speed.
基金Funded by"863"of The High-Tech Research and Development Program of China (No.2003AA602230).
文摘A research about the ultrasonic phased array imaging principle from A-scan signal to B-scan image for non-destructive testing （NDT） was conducted in this paper, the ultrasonic phased array inspection imaging system used in industrial field was developed and the experiment was performed on the steel testing block by the system with 64 elements, 5 MHz phased array transducer. Experimental results show that the flaws could be accurately detected and the flaws size could be estimated from the B-scan images, and the B-scan images could clearly show the location of the flaws, but the quality of B-scan images needs to be enhanced by digital signal processing and controlling dynamic focusing for improving the image resolution.
基金the National Key R&D Program of China(Grant No.2018YFB1106100)。
文摘The laser powder bed fusion(L-PBF)method of additive manufacturing(AM)is increasingly used in various industrial manufacturing fields due to its high material utilization and design freedom of parts.However,the parts produced by L-PBF usually contain such defects as crack and porosity because of the technological characteristics of L-PBF,which affect the quality of the product.Laser ultrasonic testing(LUT)is a potential technology for on-line testing of the L-PBF process.It is a non-contact and non-destructive approach based on signals from abundant waveforms with a wide frequency-band.In this study,a method of LUT for on-line inspection of L-PBF process was proposed,and a system of LUT was established approaching the actual environment of on-line detection to evaluate the method applicability for defects detection of L-PBF parts.The detection results of near-surface defects in L-PBF 316L stainless steel parts show that the crack-type defects with a sub-millimeter level within 0.5 mm depth can be identified,and accordingly,the positions and dimensions information can be acquired.The results were verified by X-ray computed tomography,which indicates that the present method exhibits great potential for on-line inspection of AM processes.
基金Funded by National Natural Science Foundation of China(Nos.51878350,11832013,52078250)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_0236)。
文摘Basic magnesium sulfate cement coral aggregate concrete(MCAC)is a new type of concrete consisting of basic magnesium sulfate cement,coarse coral aggregate,coral reef sand and seawater.The rebound hammer(RH),the ultrasonic pulse velocity(UPV)and the compressive strength(fcu)tests of 14 sets of cube specimens of the MCAC after 28 d of aging were conducted.The impact of the content and length of sisal fiber on the relationship between the fcu-RH and the fcu-UPV was determined.A mathematical model was established to predict the strength of the MCAC using the UPV,RH,and comprehensive UPV/RH methods and to obtain the curves of test strength.The applicability of the test strength curves of ordinary portland concrete(OPC),light-weight aggregate concrete(LAC),and coral aggregate concrete(CAC)to MCAC was assessed.The results showed that the test strength curves of OPC,LAC and CAC were inappropriate to determine the strength of MCAC using non-destructive method.The relative standard error of the curves of test strength of the RH method and the comprehensive method met the specifications,whereas that of the UPV method did not.
文摘Ultrasonic testing is a very important non-destructive method for testing components for safety of nuclear power plants and other security and delicate parts in other industries. Nowadays, thanks to the development of computer technology, it is possible to simulate processes which occur during ultrasonic testing. That is why numerical simulations are becoming an integral part of non-destructive testing. Simulations are used to determine parameters of ultrasonic examination, especially parameters of probes and scan plan and also in the analysis of results. They are used in such cases, when it is necessary to verify applicability of probes and methods. This verification could be provided on the weld and test block which are not manufactured. It could be also provided on defects, which are not manufactured in test block, but their presence is possible in given weld joint. Simulations are very useful for verifying the propagation of ultrasonic signal in given area (e.g. weld area). If movement of probe is limited, possibility of whole volume scan should be verified.
文摘Nondestructive testing technology is a common technology in the building quality testing work to complete the detection through energy body penetration. The interior of the building can be inspected without much affecting or damaging the building. In practice, the nondestructive detection technology is more efficient and has more accurate identification results. Therefore, the construction enterprises should increase the research and application of nondestructive testing technology to improve the level of construction technology. This paper also analyzes the application of nondestructive testing technology in construction engineering testing.
基金support from the Australian Research Council(ARC)through Discovery Project DP210102224.
文摘The crack initiation stress threshold is widely used in excavation industries as rock spalling strength when designing deep underground structures to avoid unwanted brittle failures.While various strain-based methods have been developed for the estimation of this critical design parameter,such methods are destructive and often requires subjective interpretations of the stress–strain curves,particularly in rocks with pre-existing microcracks or high porosity.This study explore the applicability of non-destructive ultrasonic through-transmission methods for determining rock damage levels by assessing the changes in transmitted signal characteristics during loading.The change in velocity,amplitude,dominant frequency,and root-mean-square voltage are investigated with four different rock types including marble,sandstone,granite,and basalt under various stress levels.Results suggest the rate of signal variations can be reliably used to estimate crack closure and crack initiation stress levels across the tested rocks before failure.Comparison of the results between the conventional techniques and the new proposed methods based on ultrasonic monitoring are further discussed.
基金Project(No.20045006071-27)supported by the Youth Chengguang Project of Science and Technology of Wuhan City of Chinathe Open Foundation of Hubei Key Laboratory of Modern Manufacture Quality Engineering(No.LMQ2005B07).
文摘Wall thickness is always a key index for boiler tube inspection in power plant,in order to improve the inspection efficiency and accuracy,a new method fusing the magnetic and ultrasonic technique was proposed.The magnetic technique was used to do full inspection and locate the flaws,and the ultrasonic was employed to implement further quantitative inspection accu- rately.After comparing the precision of the polynomial,exponential and logarithmic function,the polynomial model was selected to fit the relations between the wall thickness and the peak value of magnetic signals,and the data measured by ultrasonic thickness meter was used to calibrate the model parameters online,the defect depth can be sized quickly.The experimental results demon- grate that the model used in this system has better accuracy than the statistics relation model clearly,and it is also suitable for defect evaluation real-time.Moreover,it is unnecessary to have much more experimental data for the curve fitting technology,so it has better practicability than the other methods.
基金the National Natural Science Foundation of China(Grant No.11774377)。
文摘To overcome the inherent limits of traditional single wave imaging for nondestructive testing,the multi-wave focusing and imaging method is thoroughly studied.This method makes the compressional waves and shear waves focused in both emission and reception processes,which strengthens the focusing energy and improves the signal-to-noise ratio of received signals.A numerical model is developed to study the characteristics of a multi-wave focusing field.It is shown that the element width approaching 0.8 wavelengths of shear waves can keep a balance between the radiation energy of two waves,which can achieve a desirable multi-wave focusing performance.And an experiment using different imaging methods for a linear phased array is performed.It can be concluded that due to the combination of the propagation and reflection characteristics of two waves,the multi-wave focusing and imaging method can significantly improve the imaging distinguishability of defects and expand the available sweeping range to a sector of-650 to 65°.
文摘Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetration, well direction, high sensitivity, low cost, and harmless to people and material. The technologies of the computer, NC (Numerical control), precision mechanism, signal analysis and processing were integrated in the testing system. The system includes a PC, system software, ultrasonic data acquisition card, stepper motor drive card and five-axis precision mechanical device, etc. The software was developed using WIN98-based VC++. According to CAD data of the parts and interpolation methods, the scanning programs can be programmed. The five-axis scanning system is driven by the CNC(computer numerical control) system to control the attitude of ultrasonic probes. The system’s automatic scanning for complex surface parts, real-time acquiring ultrasonic data and automatic identifying flaw signal have been realized. This system can be used not only for testing complex surface parts, but for testing random curve parts. With fast testing speed, high sensitivity, high testing precision and high reliability, the system has a wide adaptability.
文摘The non-destructive testing of brazed joint in honeycomb structure with thin panel （ thickness ： 0. 2 mm） was studied by ultrasonic C-scan method. Samples with different types of artificial defect were designed; the characteristic signal and the main parameters of the test were determined by the pre-experiment, and then parameters were optimized by orthogonal design, finally the optimum process was verified by a single panel sample. The multiple reflection echoes were chosen as the characteristic signal. The optimal C-scan results were achieved when the 20 MHz focus probe was used, and the pass band range for received signal were selected as 8 - 17. 5 MHz. The defects such as incomplete penetration and core damage can be detected with ultrasonic C-scan, and the detection accuracy can reach to 1 ram.
