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Acoustic emission method for research and control of friction pairs
/VD T Abstracts 47012 Sarychev, G.A.; Shchavelin, V.M. Acoustic emission m e t h o d for research a n d control of friction pairs Tribology International, Vol, 24, No. 1, pp. 11-16 (Feb. 1991) Basic experimental results of AE in friction are presented and analysed. Using AE signals we can get an indication about the state of the friction processes, about the quality of solid and liquid layers on the contacting surfaces in real time, sometimes about intensity of wear, changing of wear and friction regimes and so on. The influence of sliding velocity, load, roughness and some physical and mechanical properties of the body on the parameters of AE are also given. Some attention to the practical implementation of these techniques for control of capability for work of friction pairs in real conditions are given.
Gao, X.-J.; Murota, K.; Tom#a, Y.; Ono, M.; Higo, Y.; Numomura, S. E v a l u a t i o n of the fixation of artificial hip j o i n t by acoustic 47004
emission Proceedings of the 10th Symposium on Ultrasonic Electronics, Tokyo (Japan), 7-9 Nov. 1989. Japanese Journal of Applied Physics, Vol. 29, Supp. 29-1, pp. 215-217 (1990). The fixation between an artificial joint and the bone becomes loose with time. To avoid this loosening, and there by increase the life of the artificial joint, it is important to detect the loosening at a very early stage. In this paper, we tried to detect the loosening of an artificial hip joint by recognizing analyzing acoustic emission from it. More than 200 measurements were taken and it is clear that the AE method is very efficient and sensitive for evaluation of the fixation condition of an artificial joint. 46822 Haynes, H.D. R e c e n t i m p r o v e m e n t s in check valve monitoring methods Oak Ridge National Lab., Tennessee (United States), DE91004392/GAR, 37 pp. (1990) ORNL has carried out an evaluation of three check valve monitoring methods acoustic emission, ultrasonic inspection, and magnetic flux signature analysis (MFSA). This work has focused on determining the capabilities of each method to provide diagnostic information useful in determining check valve aging and service wear effects (degradation) and undesirable operating modes. In addition, two novel nonintrusive monitoring methods were developed (external at-and de-magnetic monitoring) that provide several improvements over the other methods. None of the examined methods could, by themselves, monitor the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acousttc emission monitoring with one of the other methods provides the means to determine vital check valve operational information. 46794
Bearing monitoring helps plant run more smoothly Steel Times, Vot. 219, No. 4, pp. 196-198 (Apr. 1991) This article describes a new technique, spectral emitted energy (SEE), for detecting bearing defects in service. It is a high frequency acoustic emission method in which a signal from a transducer is filtered in the range 250-350 KHz and enveloped. A low pass filter then ensures that only the low frequency envelope components remain and these can be analysed using normal analysis equipment. Detection of different types of potential failures can be achieved in a variety of ways such as measuring vibration level, acoustic emission, temperature, power and stress/strain conditions. Practical trials have shown that SEE can be used to identify heating damage on compressors and pumps.
Siegmann, A.; Kander, R.G. In situ acoustic emission monitoring and mechanical testing in the scanning electron microscope
46790
Journal of Materials Science Letters, Vot. 10, No. 11, pp. 619-621. (1 Jun. 1991) This article examines the use of acoustic emission testing as a method of examining damage accumulation in composite materials. A technique has been developed for simultaneous acoustic emission and scanning electron microscope monitoring of irreversible deformation in fibre- reinforced composite materials. Thus damage development can be observed and monitored while the material is still under load to avoid post failure relaxation. AE events with amplitudes of 60-65 dB have been observed under test conditions to be assigned to matrix damage in the test composite.
Liberty Techn. Cent. Non-invasive system for inspection of valves uses acoustic and magnetic techniques to measure check valve disk motion and internal impacts or v i b r a t i o n s
46530
European Patent No. 410,317 (30 Jan. 1991)
216
NDT&E International 1994 Volume 27, Number 4
46296 Yoneyama, T.; Sato, 1., Ham, H.; Tanaka, T.; Sato, K. E v a l u a t i o n of AE b e h a v i o r a n d tribological condition for r o t a r y c o m p r e s s o r using acoustic emission t e c h n i q u e (In J a p a n e s e ) Journal of the Japanese Society of Tribologists, Vol. 35, No. 10, pp. 718-725 (1990) 46054 Bansal, V.; Gupta, B.C.; Prakash, A.; Eshwar, V.A. Q u a l i t y inspection of rolling element b e a r i n g using acoustic
emission technique Journal of Acoustic Emission, Vol. 9, No. 2, pp. 142-146 (1990) Several on-line inspection techniques are available to identify the condition of bearings including shock pulse measurements (SPM) and acoustic emission (AE) testing. The present paper provides a comparison between the SPM and AE techniques. The study indicates that the quality inspection of ball bearings by AE technique is in good agreement with SPM technique. 45815 Chi-Liang, J. Intelligent acoustic emission sensing in machining for tool
condition monitoring Dissertation Abstracts International Vol. 51, No. 5, pp. 2575-B (Nov. 1990) (DA9028894) This dissertation describes the development of an intelligent acoustic emission based sensing system for tool condition monitoring in untended machining operations. The acoustic emission generated from the sliding contact of metal-metal pairs using pin-on-disk tests is first investigated. A method for recognizing tool wear states in a turning operation from the integrated information of cutting force and acoustic emission signals is presented. It was shown that the normalized residual variance (NRV), a dimensionless feature extracted from the lattice filter scheme, proved to be a valuable index for tool wear monitoring in single-tooth as well as multi-tooth milling under a wide range of cutting conditions. Finally, the decision tree method and the group method of data handling (GMDH), due to their self-organizing capability for sensor integration, diagnostic reasoning and decision making, were adopted for the recognition and prediction of the tool wear state.
Anon. SEE technology for condition monitoring of bearings
45814
Design Engineering, pp. 43, 46 (Jan. 1991) A new technique for the detection of bearing defects has been developed at the SKF Engineering & Research Centre (ERC), based on an analysis of High Frequency Acoustic Emission (HF-AE). This technology is marketed under the name SEE (spectral emitted energy), and has proven to be a sensitive method of detecting bearing defects. Correction of the defect can be carried out before its leads to costly machine failure.
Miller, R.K. Acoustic emission testing of storage tanks
45810
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.
Holroyd, T.I.; King, S.; Randall, N. Machine condition monitoring via stress wave sensing
45809
Condition Monitoring and Diagnostic Technology, Vol. 1, No. 3, pp. 95- 98 (Jan. 1991) Stress Wave Sensing (SWS) seeks to detect and analyze transient processes in machine.s where inadequately lubricated surfaces are brought together, in order to reveal on-line information about the operation of the machine. Stress waves are trapped in a structure by the large acoustic impedance mismatch between solid and air. Their diffuse energy fields can be detected with special sensors which excludes lower frequencies and hence offer freedom of positioning, the design and mode of operation of such a sensor is described in this paper. In condition monitoring the sensing of naturally occurring high frequency stress wave activity offers additional information to conventional methods.
Gao, X.-J.; Murota, K.; Tom#a, Y.; Ono, M.; Higo, Y.; Numomura, S. E v a l u a t i o n of the fixation of artificial hip j o i n t by acoustic 47004
emission Proceedings of the 10th Symposium on Ultrasonic Electronics, Tokyo (Japan), 7-9 Nov. 1989. Japanese Journal of Applied Physics, Vol. 29, Supp. 29-1, pp. 215-217 (1990). The fixation between an artificial joint and the bone becomes loose with time. To avoid this loosening, and there by increase the life of the artificial joint, it is important to detect the loosening at a very early stage. In this paper, we tried to detect the loosening of an artificial hip joint by recognizing analyzing acoustic emission from it. More than 200 measurements were taken and it is clear that the AE method is very efficient and sensitive for evaluation of the fixation condition of an artificial joint. 46822 Haynes, H.D. R e c e n t i m p r o v e m e n t s in check valve monitoring methods Oak Ridge National Lab., Tennessee (United States), DE91004392/GAR, 37 pp. (1990) ORNL has carried out an evaluation of three check valve monitoring methods acoustic emission, ultrasonic inspection, and magnetic flux signature analysis (MFSA). This work has focused on determining the capabilities of each method to provide diagnostic information useful in determining check valve aging and service wear effects (degradation) and undesirable operating modes. In addition, two novel nonintrusive monitoring methods were developed (external at-and de-magnetic monitoring) that provide several improvements over the other methods. None of the examined methods could, by themselves, monitor the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acousttc emission monitoring with one of the other methods provides the means to determine vital check valve operational information. 46794
Bearing monitoring helps plant run more smoothly Steel Times, Vot. 219, No. 4, pp. 196-198 (Apr. 1991) This article describes a new technique, spectral emitted energy (SEE), for detecting bearing defects in service. It is a high frequency acoustic emission method in which a signal from a transducer is filtered in the range 250-350 KHz and enveloped. A low pass filter then ensures that only the low frequency envelope components remain and these can be analysed using normal analysis equipment. Detection of different types of potential failures can be achieved in a variety of ways such as measuring vibration level, acoustic emission, temperature, power and stress/strain conditions. Practical trials have shown that SEE can be used to identify heating damage on compressors and pumps.
Siegmann, A.; Kander, R.G. In situ acoustic emission monitoring and mechanical testing in the scanning electron microscope
46790
Journal of Materials Science Letters, Vot. 10, No. 11, pp. 619-621. (1 Jun. 1991) This article examines the use of acoustic emission testing as a method of examining damage accumulation in composite materials. A technique has been developed for simultaneous acoustic emission and scanning electron microscope monitoring of irreversible deformation in fibre- reinforced composite materials. Thus damage development can be observed and monitored while the material is still under load to avoid post failure relaxation. AE events with amplitudes of 60-65 dB have been observed under test conditions to be assigned to matrix damage in the test composite.
Liberty Techn. Cent. Non-invasive system for inspection of valves uses acoustic and magnetic techniques to measure check valve disk motion and internal impacts or v i b r a t i o n s
46530
European Patent No. 410,317 (30 Jan. 1991)
216
NDT&E International 1994 Volume 27, Number 4
46296 Yoneyama, T.; Sato, 1., Ham, H.; Tanaka, T.; Sato, K. E v a l u a t i o n of AE b e h a v i o r a n d tribological condition for r o t a r y c o m p r e s s o r using acoustic emission t e c h n i q u e (In J a p a n e s e ) Journal of the Japanese Society of Tribologists, Vol. 35, No. 10, pp. 718-725 (1990) 46054 Bansal, V.; Gupta, B.C.; Prakash, A.; Eshwar, V.A. Q u a l i t y inspection of rolling element b e a r i n g using acoustic
emission technique Journal of Acoustic Emission, Vol. 9, No. 2, pp. 142-146 (1990) Several on-line inspection techniques are available to identify the condition of bearings including shock pulse measurements (SPM) and acoustic emission (AE) testing. The present paper provides a comparison between the SPM and AE techniques. The study indicates that the quality inspection of ball bearings by AE technique is in good agreement with SPM technique. 45815 Chi-Liang, J. Intelligent acoustic emission sensing in machining for tool
condition monitoring Dissertation Abstracts International Vol. 51, No. 5, pp. 2575-B (Nov. 1990) (DA9028894) This dissertation describes the development of an intelligent acoustic emission based sensing system for tool condition monitoring in untended machining operations. The acoustic emission generated from the sliding contact of metal-metal pairs using pin-on-disk tests is first investigated. A method for recognizing tool wear states in a turning operation from the integrated information of cutting force and acoustic emission signals is presented. It was shown that the normalized residual variance (NRV), a dimensionless feature extracted from the lattice filter scheme, proved to be a valuable index for tool wear monitoring in single-tooth as well as multi-tooth milling under a wide range of cutting conditions. Finally, the decision tree method and the group method of data handling (GMDH), due to their self-organizing capability for sensor integration, diagnostic reasoning and decision making, were adopted for the recognition and prediction of the tool wear state.
Anon. SEE technology for condition monitoring of bearings
45814
Design Engineering, pp. 43, 46 (Jan. 1991) A new technique for the detection of bearing defects has been developed at the SKF Engineering & Research Centre (ERC), based on an analysis of High Frequency Acoustic Emission (HF-AE). This technology is marketed under the name SEE (spectral emitted energy), and has proven to be a sensitive method of detecting bearing defects. Correction of the defect can be carried out before its leads to costly machine failure.
Miller, R.K. Acoustic emission testing of storage tanks
45810
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.
Holroyd, T.I.; King, S.; Randall, N. Machine condition monitoring via stress wave sensing
45809
Condition Monitoring and Diagnostic Technology, Vol. 1, No. 3, pp. 95- 98 (Jan. 1991) Stress Wave Sensing (SWS) seeks to detect and analyze transient processes in machine.s where inadequately lubricated surfaces are brought together, in order to reveal on-line information about the operation of the machine. Stress waves are trapped in a structure by the large acoustic impedance mismatch between solid and air. Their diffuse energy fields can be detected with special sensors which excludes lower frequencies and hence offer freedom of positioning, the design and mode of operation of such a sensor is described in this paper. In condition monitoring the sensing of naturally occurring high frequency stress wave activity offers additional information to conventional methods.