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Acoustic emission testing of storage tanks
ND T Abstracts 46803 Raj, B.; Jha, B.B.; Khanna, A.S.; Bhattacharya, D.K. Acoustic emission studies t o w a r d s b e t t e r u n d e r s t a n d i n g of high temperature oxidation in C r - M o steels International Journal of Pressure Vessel and Piping, Vol. 45, No. 3, pp. 301-326 (1991) Application of acoustic emission (AE) for the study of the oxidation behaviour of Cr-mo steels in a wide range of temperature is described. AE parameters, i.e. events, ring down counts, rise time, event duration and root means square voltage have been applied successfully to detect the initiation of breakaway oxidation and in-situ spailing of the oxide scales formed on 2.25Cr--=IMo and 9Cr-lMo steels at high temperatures. Time domain, frequency domain and amplitude distribution analyses were used to study these phenomena. 46793 Ouellette, P.; Hoa, S.V.; Li, L. N o n d e s t r u c t i v e evaluation of fiberglass reinforced plastic road tankers subjected to internal pressures using acoustic emission
monitoring Journal of Hazardous Materials, Vol. 25, No. 1-2, pp. 4%60 (1990) The use of fiberglass reinforced plastics (FRP) in the fabrication of road tankers for the transportation of corrosive liquid products and wastes has the potential of growing considerably in coming years. One nondestructive testing method consists of Acoustic Emission (AE) monitoring of tankers subjected to internal pressure. This paper describes the experience gained in more than 20 AE-monitored pressure tests. Eight of these tests were conducted to rupture. A new recommended test procedure is proposed based on the test results. The test consists of a fixed schedule of repeated pressure loadings, and the simultaneous measurement of the trend in AE activity. The tanker can easily be judged by the AE trend it exhibits, and it can be unambiguously accepted or rejected based on the criteria contained in the proposed procedure. While the new procedure is thought to be more general and less dependent on the experience of testing personnel, it dose not replace the CARP practice.
46564
Miller, R.K. Acoustic emission testing of storage t a n k s
Tappi 1990 Engineering Conference, Seattle, Washington (United States), 24-27 Sep. 1990. Book 2 pp. 747-751. Tappi Press (1990) Acoustic Emission Testing (AET) of metal storage tanks has been used successfully and routinely since the late 1970's. AET is done in conjunction with hydrotesting or by loading with product when it is desirable to leave the tank in production. Test procedures and analysis, in particular the MONPAC technology, have been developed in the mid 1980's for detecting and assessing structural defects. Detecting and locating leaks on tank bottoms was first introduced in 1982. Now the two technologies are being integrated into one test for determining total tank integrity. A description of these procedures and analysis will he presented along with results of actual tests. 46557
Research of acoustic emissions in natural gas vehicle storage cylinders CNG Fuel Systems Ltd., Ottawa, Ontario (Canada), MIC-9004488/GAR, 57 pp. (1987) The use of natural gas (NGV) as an auto fuel involves the on-beard storage of NGV at 3000 psig in thick wailed high strength steel cylinders. Acoustic emission testing (AET) has been proposed as an alternative to the currently used hydro testing. The report gives the details of a project to validate AET as a means of detecting active cracking. The report includes the procedures followed, the results obtained, and the final conclusions.
46552 Scruby, C.B.; Beesley, ME.; Stacey, K.A., Buttle, DE. Acoustic emission m e a s u r e m e n t s d u r i n g cyclic fatigue of welded A533B plates containing defects Commission of the European Communities, EUR- 12845-EN 40 pp (1990) A series of A533B specimens, containing realistic intentional weld fabrication defects, has been prepared and fatigue tested in the laboratory under conditions chosen to simulate those on the experimental Ispra pressure vessel. Acoustic emission has been recorded during the fatigue of these specimens under carefully controlled testing and monitoring conditions. The unique high band width AEA Technology system has been used in conjunction with new 3-D software to locate the emission events from the defects, and thereby map out their growth. New source characterisation analysis software has been used to distinguish between primary (crack advance) events and secondary events during fatigue. The study has shown conclusively that during the dry fatigue of A533B steel weldments, the acoustic emission activity is dominated by secondary events associated with crack-face fretting, sticking and unsticking. The study has also shown that there are very few primary events of sufficient amplitude to be detected, located and characterised, and that those which were recorded were concentrated in the early stage of fatigue, wl~en the defect was beginning to grow.
Lefloch, C.; Beziers, S. AECM3: acoustic emission conditions for failure prediction of 46315
winding c a r b o n s t r u c t u r e s Aerospatiale, Bordeaux (France), N90-24374/2/GAR, 7 pp. (Jut. 1989) Preliminary results of a study on the prediction by Acoustic Emission (AE) of the pressure burst of a composite pressurant tank are presented. The prediction is realized with a criterion in relation with the pressure level and defined with AE measurements. The experimental study concerns winding structures with IM6 fiber embedded in an epoxy matrix. Results are shown graphically. Unresolved questions are given.
Scruby, C.B.; Beesley, MJ.; Stacey, K.A.; Buttle, DE. Continuous monitoring by acoustic emission measurement
46313
Reactor Safety Research. Edited by W. Krischer. pp. 731-741. Elsevier Applied Science (1990) Advanced acoustic emission techniques have been applied to the monitoring of the first hydrotest and the subsequent pressure cycling of a 1/5-scale experimental PWR vessel. The same techniques have also been applied to laboratory specimens in a comprehensive series of test designed to simulate the hehaviour of weld fabrication defects under more extreme conditions of tensile loading and cyclic fatigue than could he applied to the vessel. It was concluded that fabrication defects such as slag inclusions and hot cracks generate detectable emission provided tensile loading is sufficiently high to initiate defect growth. The low level of emission activity during the vessel hydrotest was therefore consistent with a lack of significant defect growth. The specimen fatigue tests confirmed that the vast majority of the emission from fabrication defects in welds is secondary, but also showed that crack advance into low toughness material in the immediate vicinity of the defect may generate a small number of primary emissions early in fatigue, which disappear after further defect growth.
Gorman, M.R. Burst prediction by acoustic emission in filament wound
46055
46556
pressure vessels Journal of Acoustic Emission, vol. 9, No. 2, pp. 131-139 (1990) Acoustic emission in 51-cm diameter graphite/epoxy pressure vessels was monitored during pressurization (hydrotesting). This paper presents the AE event count versus pressure history of these tests and demonstrates the ability of the AE technique to monitor the growth of damage and to estimate the effect on ultimate strength. The number of events that occurred during pressure holds proved to he a reasonable estimator of vessel performance.
Transportation Development Center, Montreal, Quebec (Canada), MIC-90- 04789/GAR, 56 pp. (1989) The use of fiberglass reinforced plastic (FRP) in the transportation of corrosive and waste liquids is appealing to an increasing number of highway tanker operators. A method of acoustic emission (AE) testing FRP/BWC tankers was developed by observing AE activity trends upon repeated pressurization of the tankers. Twenty-five tanker tests were conducted; 8 of these were run to bursting pressure. A simple method of measuring AE activity trend was developed, and unambiguous accoptance/rejection criteria was proposed.
45810 Miller, R.K. Acoustic emission testing of storage t a n k s Tappi Journal, Vol. 73, No. 12, pp. 105-109 (Dec. 1990) Acoustic emission (AE) field testing can be used to monitor the condition of routinely loaded storage tanks. AE sources can be differentiated using signal processing and by comparing load status at various parts of the test. Well understood analytic techniques are then used to assess the severity of structurally significant AE sources. Triangulation is used to locate any leaks identified in this way the integrity of storage tanks can be established using AE techniques. Tank wall testing is used for defect detection and assessment, while tank bottom testing is used for leak detection and location. Recent work combines the two technologies.
Ouellette, P.; Hoa, S.V. Development of non-destructive testing methods for proving a n d re- testing low pressure, fibre reinforced plastic highway tankers
314
NDT&E International Volume 26 Number 6 1993
monitoring Journal of Hazardous Materials, Vol. 25, No. 1-2, pp. 4%60 (1990) The use of fiberglass reinforced plastics (FRP) in the fabrication of road tankers for the transportation of corrosive liquid products and wastes has the potential of growing considerably in coming years. One nondestructive testing method consists of Acoustic Emission (AE) monitoring of tankers subjected to internal pressure. This paper describes the experience gained in more than 20 AE-monitored pressure tests. Eight of these tests were conducted to rupture. A new recommended test procedure is proposed based on the test results. The test consists of a fixed schedule of repeated pressure loadings, and the simultaneous measurement of the trend in AE activity. The tanker can easily be judged by the AE trend it exhibits, and it can be unambiguously accepted or rejected based on the criteria contained in the proposed procedure. While the new procedure is thought to be more general and less dependent on the experience of testing personnel, it dose not replace the CARP practice.
46564
Miller, R.K. Acoustic emission testing of storage t a n k s
Tappi 1990 Engineering Conference, Seattle, Washington (United States), 24-27 Sep. 1990. Book 2 pp. 747-751. Tappi Press (1990) Acoustic Emission Testing (AET) of metal storage tanks has been used successfully and routinely since the late 1970's. AET is done in conjunction with hydrotesting or by loading with product when it is desirable to leave the tank in production. Test procedures and analysis, in particular the MONPAC technology, have been developed in the mid 1980's for detecting and assessing structural defects. Detecting and locating leaks on tank bottoms was first introduced in 1982. Now the two technologies are being integrated into one test for determining total tank integrity. A description of these procedures and analysis will he presented along with results of actual tests. 46557
Research of acoustic emissions in natural gas vehicle storage cylinders CNG Fuel Systems Ltd., Ottawa, Ontario (Canada), MIC-9004488/GAR, 57 pp. (1987) The use of natural gas (NGV) as an auto fuel involves the on-beard storage of NGV at 3000 psig in thick wailed high strength steel cylinders. Acoustic emission testing (AET) has been proposed as an alternative to the currently used hydro testing. The report gives the details of a project to validate AET as a means of detecting active cracking. The report includes the procedures followed, the results obtained, and the final conclusions.
46552 Scruby, C.B.; Beesley, ME.; Stacey, K.A., Buttle, DE. Acoustic emission m e a s u r e m e n t s d u r i n g cyclic fatigue of welded A533B plates containing defects Commission of the European Communities, EUR- 12845-EN 40 pp (1990) A series of A533B specimens, containing realistic intentional weld fabrication defects, has been prepared and fatigue tested in the laboratory under conditions chosen to simulate those on the experimental Ispra pressure vessel. Acoustic emission has been recorded during the fatigue of these specimens under carefully controlled testing and monitoring conditions. The unique high band width AEA Technology system has been used in conjunction with new 3-D software to locate the emission events from the defects, and thereby map out their growth. New source characterisation analysis software has been used to distinguish between primary (crack advance) events and secondary events during fatigue. The study has shown conclusively that during the dry fatigue of A533B steel weldments, the acoustic emission activity is dominated by secondary events associated with crack-face fretting, sticking and unsticking. The study has also shown that there are very few primary events of sufficient amplitude to be detected, located and characterised, and that those which were recorded were concentrated in the early stage of fatigue, wl~en the defect was beginning to grow.
Lefloch, C.; Beziers, S. AECM3: acoustic emission conditions for failure prediction of 46315
winding c a r b o n s t r u c t u r e s Aerospatiale, Bordeaux (France), N90-24374/2/GAR, 7 pp. (Jut. 1989) Preliminary results of a study on the prediction by Acoustic Emission (AE) of the pressure burst of a composite pressurant tank are presented. The prediction is realized with a criterion in relation with the pressure level and defined with AE measurements. The experimental study concerns winding structures with IM6 fiber embedded in an epoxy matrix. Results are shown graphically. Unresolved questions are given.
Scruby, C.B.; Beesley, MJ.; Stacey, K.A.; Buttle, DE. Continuous monitoring by acoustic emission measurement
46313
Reactor Safety Research. Edited by W. Krischer. pp. 731-741. Elsevier Applied Science (1990) Advanced acoustic emission techniques have been applied to the monitoring of the first hydrotest and the subsequent pressure cycling of a 1/5-scale experimental PWR vessel. The same techniques have also been applied to laboratory specimens in a comprehensive series of test designed to simulate the hehaviour of weld fabrication defects under more extreme conditions of tensile loading and cyclic fatigue than could he applied to the vessel. It was concluded that fabrication defects such as slag inclusions and hot cracks generate detectable emission provided tensile loading is sufficiently high to initiate defect growth. The low level of emission activity during the vessel hydrotest was therefore consistent with a lack of significant defect growth. The specimen fatigue tests confirmed that the vast majority of the emission from fabrication defects in welds is secondary, but also showed that crack advance into low toughness material in the immediate vicinity of the defect may generate a small number of primary emissions early in fatigue, which disappear after further defect growth.
Gorman, M.R. Burst prediction by acoustic emission in filament wound
46055
46556
pressure vessels Journal of Acoustic Emission, vol. 9, No. 2, pp. 131-139 (1990) Acoustic emission in 51-cm diameter graphite/epoxy pressure vessels was monitored during pressurization (hydrotesting). This paper presents the AE event count versus pressure history of these tests and demonstrates the ability of the AE technique to monitor the growth of damage and to estimate the effect on ultimate strength. The number of events that occurred during pressure holds proved to he a reasonable estimator of vessel performance.
Transportation Development Center, Montreal, Quebec (Canada), MIC-90- 04789/GAR, 56 pp. (1989) The use of fiberglass reinforced plastic (FRP) in the transportation of corrosive and waste liquids is appealing to an increasing number of highway tanker operators. A method of acoustic emission (AE) testing FRP/BWC tankers was developed by observing AE activity trends upon repeated pressurization of the tankers. Twenty-five tanker tests were conducted; 8 of these were run to bursting pressure. A simple method of measuring AE activity trend was developed, and unambiguous accoptance/rejection criteria was proposed.
45810 Miller, R.K. Acoustic emission testing of storage t a n k s Tappi Journal, Vol. 73, No. 12, pp. 105-109 (Dec. 1990) Acoustic emission (AE) field testing can be used to monitor the condition of routinely loaded storage tanks. AE sources can be differentiated using signal processing and by comparing load status at various parts of the test. Well understood analytic techniques are then used to assess the severity of structurally significant AE sources. Triangulation is used to locate any leaks identified in this way the integrity of storage tanks can be established using AE techniques. Tank wall testing is used for defect detection and assessment, while tank bottom testing is used for leak detection and location. Recent work combines the two technologies.
Ouellette, P.; Hoa, S.V. Development of non-destructive testing methods for proving a n d re- testing low pressure, fibre reinforced plastic highway tankers
314
NDT&E International Volume 26 Number 6 1993