The Experts below are selected from a list of 30510 Experts worldwide ranked by ideXlab platform
M. Azmi - One of the best experts on this subject based on the ideXlab platform.
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ACOUSTIC EMISSION DETECTION AND MONITORING OF HIGHWAY Bridge Components. FINAL REPORT
NDT & E International, 1992Co-Authors: D.w. Vannoy, M. AzmiAbstract:Over ten thousand highway Bridges in the United States reach their fatigue life limits every year. This emphasizes on the need for developing an effective method for evaluation of the structural integrity of those structures. The current inspection of highway Bridges depends on the visual examination, ultrasonic and occasional radiographic techniques that have shown a low degree of reliability in detecting small cracks. Application of acoustic emission technique in the aerospace and nuclear industries have proved considerable capabilities in detecting extremely small crack growth increments. This technique was used in this study to characterize acoustic emission signals that are related to the growth of fatigue cracks in Bridge Components. A number of welded and rolled beams and small specimens were subjected to cyclic loadings in the laboratory. Acoustic emission data were obtained and evaluated in the time and frequency domains. It was concluded that the acoustic emission technique may provide a positive solution to the existing problem of detecting small fatigue cracks in highway Bridge structures.
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ACOUSTIC EMISSION DETECTION AND MONITORING OF HIGHWAY Bridge Components
1991Co-Authors: D.w. Vannoy, M. AzmiAbstract:Fatigue cracking is the most common problem in steel highways Bridges. Early detection of cracks requires simple, inexpensive repairs, whereas late detection of cracks may cause catastrophic accidents. Currently, the Bridges are inspected by visual examination, dye penetrant, magnetic particles, ultrasonics, and radiography. Low reliability and high inspection costs require a more efficient inspection system to be developed. Acoustic emission (AE) seems to be the solution to these problems. It has developed over the past two decades as a nondestructive testing technique with high sensitivity to detect progressive microscopic events in the material. Development of portable AE equipment has made it an even more practical method for Bridge inspections. In a prior study, acoustic emission was applied to A588 weathering steel beams (rolled and welded sections), and the effective frequency range for monitoring highway Bridges was established. In this study, research characterizing the parameters of cracks versus noise was conducted. A total of 18 beams made of A588 steel including welded, rolled and coverplated beams, were monitored. Half of the beams were exposed to severe atmospheric environments to investigate the effect of rusting on the AE signals. Also, a total of twelve small specimens made from the same material were monitored to establish a relationship between the AE signals and stress intensity factors. In addition, three small welded specimens were monitored for comparison to the coverplated beams. As a result of this study, a statistical range of variation of the AE parameters at various stages of crack growth has been established. This range can be used as a reference for Bridge inspection. A model for predicting the stage of crack growth versus AE parameters has been discussed, and a systematic inspection procedure by AE has been recommended.
U B Halabe - One of the best experts on this subject based on the ideXlab platform.
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nde of frp wrapped timber Bridge Components using infrared thermography
REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION:Volume 22, 2003Co-Authors: U B Halabe, W E Steele, Hota V S Gangarao, Penprapa KlinkhachornAbstract:This paper presents the results of an experimental study on the use of infrared thermography technique for detection of subsurface debonds in fiber reinforced polymer (FRP) wrapped timber railroad Bridge Components. Simulated subsurface debonds were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The debonds varied in size, thickness and severity. These debonds were placed between the 1/8″ thick FRP wrap and the timber surface. The thermal images from the delaminated specimens were compared with the thermal images from undamaged specimens to study the effect of subsurface debonds. In addition, several field tests were conducted using the infrared imaging system on three timber railroad Bridges located in Moorefield, West Virginia that were rehabilitated with FRP composite fabric wraps. The field test data was used to detect any possible debond at the composite‐timber interface and study the effect of environmental parameters on the infrared images. This study showed that t...
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NDE of FRP Wrapped Timber Bridge Components Using Infrared Thermography
AIP Conference Proceedings, 2003Co-Authors: U B Halabe, W E Steele, Hota V S Gangarao, Penprapa KlinkhachornAbstract:This paper presents the results of an experimental study on the use of infrared thermography technique for detection of subsurface debonds in fiber reinforced polymer (FRP) wrapped timber railroad Bridge Components. Simulated subsurface debonds were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The debonds varied in size, thickness and severity. These debonds were placed between the 1/8″ thick FRP wrap and the timber surface. The thermal images from the delaminated specimens were compared with the thermal images from undamaged specimens to study the effect of subsurface debonds. In addition, several field tests were conducted using the infrared imaging system on three timber railroad Bridges located in Moorefield, West Virginia that were rehabilitated with FRP composite fabric wraps. The field test data was used to detect any possible debond at the composite‐timber interface and study the effect of environmental parameters on the infrared images. This study showed that the infrared thermography technique can be effectively used to detect subsurface debonds in timber Components wrapped with FRP composite fabric. The study also shows the effect of different parameters (environmental conditions, heat source, etc.) on the infrared images.
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nondestructive evaluation of frp composite Bridge Components using infrared thermography
Quantitative Nondestructive Evaluation, 2002Co-Authors: U B Halabe, Penprapa Klinkhachorn, Hota V S Gangarao, H Alqennah, Edward SazonovAbstract:This paper presents the findings of an experimental study on the use of Infrared Thermography for nondestructive evaluation of subsurface delaminations in Fiber Reinforced Polymer (FRP) composite Bridge decks and concrete columns wrapped with FRP jackets. Composite Bridge deck specimens were constructed in the laboratory with varying delamination sizes. The infrared images from the delaminated specimens were compared with undamaged specimens to study the effect of subsurface delaminations on the infrared images. In addition, field tests were conducted using infrared thermography on composite structural members of three Bridges located in West Virginia.
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condition assessment of frp composite Bridge Components using infrared thermography
Rehabilitating and Repairing the Buildings and Bridges of the Americas Conference 2001, 2002Co-Authors: U B Halabe, Hota V S Gangarao, H AlqennahAbstract:This paper presents the findings of an experimental study on the use of Infrared Thermography for nondestructive evaluation of subsurface delaminations in Fiber Reinforced Polymer (FRP) composite Bridge decks and concrete columns wrapped with FRP jackets. Composite Bridge deck specimens were constructed in the laboratory with varying subsurface delamination conditions such as sizes, thicknesses and filler materials. These simulated delaminations were placed between the 3/8" thick wearing surface and the top of the FRP deck. The laboratory specimens were tested using an infrared imaging system. The infrared images from the delaminated specimens were compared with solid (undamaged) specimens to study the effect of subsurface delaminations on the infrared images under controlled laboratory conditions. In addition, field tests were conducted using infrared thermography on the FRP composite decks of two Bridges (Wickwire Run and Laurel Lick) located in West Virginia. The field tests were used to detect subsurface delaminations and study the effect of environmental parameters on the infrared images. As an additional example, infrared testing was conducted to evaluate FRP wrapping and detect debonding between the FRP wraps and concrete columns in the Pond Creek Bridge in West Virginia. This study shows that the infrared thermography technique can be used effectively for rapid evaluation of subsurface condition of FRP composite Bridge decks and wrapped columns. The study also shows how the environmental conditions (e.g., Department of Civil and Environmental Engineering, Constructed Facilities Center, College of Engineering and Mineral Resources, West Virginia University, P.O. Box 6103, Morgantown, WV, 26506-6103; phone 304-293-7608; uhalabe@alum.mit.edu 2 Department of Civil and Environmental Engineering, Constructed Facilities Center, College of Engineering and Mineral Resources, West Virginia University, P.O. Box 6103, Morgantown, WV, 26506-6103; phone 304-293-3031; fax 304-293-7109 hota.gangarao@mail.wvu.edu 3 RBA Group, 600 Old Pond Road, Bldg. 500, Suite 501, Bridgeville, PA, 15017; phone 412-221-0800; halqennah@hotmail.com
Penprapa Klinkhachorn - One of the best experts on this subject based on the ideXlab platform.
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nde of frp wrapped timber Bridge Components using infrared thermography
REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION:Volume 22, 2003Co-Authors: U B Halabe, W E Steele, Hota V S Gangarao, Penprapa KlinkhachornAbstract:This paper presents the results of an experimental study on the use of infrared thermography technique for detection of subsurface debonds in fiber reinforced polymer (FRP) wrapped timber railroad Bridge Components. Simulated subsurface debonds were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The debonds varied in size, thickness and severity. These debonds were placed between the 1/8″ thick FRP wrap and the timber surface. The thermal images from the delaminated specimens were compared with the thermal images from undamaged specimens to study the effect of subsurface debonds. In addition, several field tests were conducted using the infrared imaging system on three timber railroad Bridges located in Moorefield, West Virginia that were rehabilitated with FRP composite fabric wraps. The field test data was used to detect any possible debond at the composite‐timber interface and study the effect of environmental parameters on the infrared images. This study showed that t...
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NDE of FRP Wrapped Timber Bridge Components Using Infrared Thermography
AIP Conference Proceedings, 2003Co-Authors: U B Halabe, W E Steele, Hota V S Gangarao, Penprapa KlinkhachornAbstract:This paper presents the results of an experimental study on the use of infrared thermography technique for detection of subsurface debonds in fiber reinforced polymer (FRP) wrapped timber railroad Bridge Components. Simulated subsurface debonds were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The debonds varied in size, thickness and severity. These debonds were placed between the 1/8″ thick FRP wrap and the timber surface. The thermal images from the delaminated specimens were compared with the thermal images from undamaged specimens to study the effect of subsurface debonds. In addition, several field tests were conducted using the infrared imaging system on three timber railroad Bridges located in Moorefield, West Virginia that were rehabilitated with FRP composite fabric wraps. The field test data was used to detect any possible debond at the composite‐timber interface and study the effect of environmental parameters on the infrared images. This study showed that the infrared thermography technique can be effectively used to detect subsurface debonds in timber Components wrapped with FRP composite fabric. The study also shows the effect of different parameters (environmental conditions, heat source, etc.) on the infrared images.
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nondestructive evaluation of frp composite Bridge Components using infrared thermography
Quantitative Nondestructive Evaluation, 2002Co-Authors: U B Halabe, Penprapa Klinkhachorn, Hota V S Gangarao, H Alqennah, Edward SazonovAbstract:This paper presents the findings of an experimental study on the use of Infrared Thermography for nondestructive evaluation of subsurface delaminations in Fiber Reinforced Polymer (FRP) composite Bridge decks and concrete columns wrapped with FRP jackets. Composite Bridge deck specimens were constructed in the laboratory with varying delamination sizes. The infrared images from the delaminated specimens were compared with undamaged specimens to study the effect of subsurface delaminations on the infrared images. In addition, field tests were conducted using infrared thermography on composite structural members of three Bridges located in West Virginia.
Dimitri A. Grivas - One of the best experts on this subject based on the ideXlab platform.
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RELIABILITY-BASED PERFORMANCE MODEL FOR LARGE Bridge COMPONENT SYSTEMS
Transportation Research Record, 1997Co-Authors: P D Destefano, Dimitri A. GrivasAbstract:A method for modeling the performance of large Bridge Components subjected to normal loading and deterioration effects using reliability engineering techniques is presented. Development of the method was motivated by the need to advance a practical performance model for large Bridge rehabilitation decision analysis. The modeling scope includes three basic elements: performance assessment, system modeling, and failure rate analysis. Two fundamental assumptions of the developed performance model are that (a) Bridge Components are systems of independent critical elements and (b) each element's failure rate is constant throughout its functional service life. The model is used to qualitatively assess the performance of Bridge Components with respect to reliability and enables the estimation of two important rehabilitation planning indices, functional service life and expected damage. An application of the model is illustrated in an example involving a comparative evaluation of the performance of two large brid...
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Reliability-Based Performance Model for Large Bridge Component Systems
Transportation Research Record: Journal of the Transportation Research Board, 1997Co-Authors: P D Destefano, Dimitri A. GrivasAbstract:A method for modeling the performance of large Bridge Components subjected to normal loading and deterioration effects using reliability engineering techniques is presented. Development of the method was motivated by the need to advance a practical performance model for large Bridge rehabilitation decision analysis. The modeling scope includes three basic elements: performance assessment, system modeling, and failure rate analysis. Two fundamental assumptions of the developed performance model are that (a) Bridge Components are systems of independent critical elements and (b) each element’s failure rate is constant throughout its functional service life. The model is used to qualitatively assess the performance of Bridge Components with respect to reliability and enables the estimation of two important rehabilitation planning indices, functional service life and expected damage. An application of the model is illustrated in an example involving a comparative evaluation of the performance of two large Bridge deck systems. The Bridges selected have similar traffic, maintenance, and environmental conditions; however, they have significantly different design characteristics. It is concluded that the performance model provides a viable approach to qualitative and quantitative evaluation of Bridge performance over time. The research efforts described are part of a larger, comprehensive project to develop and enhance the Bridge management system of the New York State Thruway Authority.
D.w. Vannoy - One of the best experts on this subject based on the ideXlab platform.
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ACOUSTIC EMISSION DETECTION AND MONITORING OF HIGHWAY Bridge Components. FINAL REPORT
NDT & E International, 1992Co-Authors: D.w. Vannoy, M. AzmiAbstract:Over ten thousand highway Bridges in the United States reach their fatigue life limits every year. This emphasizes on the need for developing an effective method for evaluation of the structural integrity of those structures. The current inspection of highway Bridges depends on the visual examination, ultrasonic and occasional radiographic techniques that have shown a low degree of reliability in detecting small cracks. Application of acoustic emission technique in the aerospace and nuclear industries have proved considerable capabilities in detecting extremely small crack growth increments. This technique was used in this study to characterize acoustic emission signals that are related to the growth of fatigue cracks in Bridge Components. A number of welded and rolled beams and small specimens were subjected to cyclic loadings in the laboratory. Acoustic emission data were obtained and evaluated in the time and frequency domains. It was concluded that the acoustic emission technique may provide a positive solution to the existing problem of detecting small fatigue cracks in highway Bridge structures.
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ACOUSTIC EMISSION DETECTION AND MONITORING OF HIGHWAY Bridge Components
1991Co-Authors: D.w. Vannoy, M. AzmiAbstract:Fatigue cracking is the most common problem in steel highways Bridges. Early detection of cracks requires simple, inexpensive repairs, whereas late detection of cracks may cause catastrophic accidents. Currently, the Bridges are inspected by visual examination, dye penetrant, magnetic particles, ultrasonics, and radiography. Low reliability and high inspection costs require a more efficient inspection system to be developed. Acoustic emission (AE) seems to be the solution to these problems. It has developed over the past two decades as a nondestructive testing technique with high sensitivity to detect progressive microscopic events in the material. Development of portable AE equipment has made it an even more practical method for Bridge inspections. In a prior study, acoustic emission was applied to A588 weathering steel beams (rolled and welded sections), and the effective frequency range for monitoring highway Bridges was established. In this study, research characterizing the parameters of cracks versus noise was conducted. A total of 18 beams made of A588 steel including welded, rolled and coverplated beams, were monitored. Half of the beams were exposed to severe atmospheric environments to investigate the effect of rusting on the AE signals. Also, a total of twelve small specimens made from the same material were monitored to establish a relationship between the AE signals and stress intensity factors. In addition, three small welded specimens were monitored for comparison to the coverplated beams. As a result of this study, a statistical range of variation of the AE parameters at various stages of crack growth has been established. This range can be used as a reference for Bridge inspection. A model for predicting the stage of crack growth versus AE parameters has been discussed, and a systematic inspection procedure by AE has been recommended.