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Measuring equipment of residual stress in railroad wheel by EMAT
= J S N D I a b s tra c tsEnglish abstracts of full papers published in Japanese in the official Journal of the Japanese Society for Non-Destructive Inspection (JSNDI) ISSN 0367-5866 J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 23
J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 88
Uraoaki, Hiroshi; Hirose, Sadao; Kobayashi, Osamu; Yamamoto, Takehiko
Mihara, Tsuyoshi; Yamada, Yoko; Kanno, Toru
Quantitative analysis of echo amplitude in ultrasonic testing for high attenuation materials using broad band probe A calculation method of a flaw echo amplitude was analyzed about ultrasonic testing for high attenuation materials using a broad band probe. A graphite material was used in this study and its frequency dependency of attenuation coefficient was measured based on the spectrum distributions of multiple bottom echoes. In the results of this experiment, a linear relationship was existing between frequency and attenuation coefficient. The echo amplitude from a flaw can be presented as sum of the echo amplitudes in the each frequency component using the spectrum distribution of the first bottom echo of the calibration block type JIS-STB-A1, which is regarded to be equal to that of the transmitted ultrasonic pulse, and the attenuation coefficient of each frequency component. Calculated value of distance amplitude characteristic curve showed a good correspondence with measured value.
Spectrum analysis of ultrasonic backscattering depending on regularly-arranged microstructural distribution Authors investigate the relationship between spectrum of ultrasonic backscattering signals and microstructures of materials for the basic study of nondestructive evaluation of materials. We propose the simple simulation of backscattered signal spectrum for the qualitative estimation of backscattering in various microstructures. To confirm the availability of the simulation, laminated plate model, regularly-arranged fiber in water model and fiber in resin model are fabricated and the spectrum of backscattered echo of each is measured experimentally. In results, the simulations of the spectrum estimation coincide well to experimental results for all the model specimens. Spectrum of backscattering echo, therefore, could be utilizing to the non-destructive estimation of interval of regulariy-arranged scattering source in materials.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 29 J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 95
Fujisawa, Kazuo; Murayama, Riichi; Yonehara, Sadao; Sakamoto, Haruo Measuring equipment of residual stress in railroad wheel by EMAT Residual stress in the rim of railroad wheel was measured nondestructively by using acoustoelasticity. The propagation time of shear waves polarized in the directions of circumference and radius was measured with Electromagnetic Acoustic Transucer (EMAT) which transmits and receives ultrasonic wave without acoustic couplant. The measuring time was two seconds at each measuring point. The basic experiments showed that the stress was measured with an accuracy of 20 MPa by using EMAT measuring equipment. The field test was also continued for a year to evaluate the residual stress change in the rim of railroad wheels of a locomotive. It is concluded that the residual stress change of the rim is measured with high accuracy by using the EMAT measuring equipment.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 36
Zhano, Yaobano; Sekine, Kazuyoshi; Watanabe, Shinsuke The force on a magnetic particle in the leakage field above the surface-breakingflaw This paper theoretically analyses the magnetic force acting on the magnetic particle in the leakage field caused by surface-breaking flaws. The analysis is based on the modified magnetic dipole model concerning the leakage field, which has been already proposed by the authors. Appropriate analytic expressions have been given to facilitate the numerical computation for the magnetic force of particle. The computed results using the proposed expressions on the magnetic force have been compared with those predicted from the classical dipole model, and there were remarkable differences in the feature of magnetic force distributions between them in the condition of very small lift-off values. As the result of investigation for the characteristics of magnetic force predicted by the present analysis, it was found that the magnetic force attracts the magnetic particles to the neighborhood of the both corners of flaw on the surface, while the classical model shows the attractive force in the direction of the center of flaw top-surface.
Yoneyama, Tokao; Sato, Ichiya; Michimoto, Syozo; Kiguchi, Keichi; Sugiyama, Youichi; Taguchi, Yuji; Yanagibashi, Minoru Generation method of diagnostic algorithms with AE technique for mass produced goods The acoustic emission (AE) technique is a useful means of machine-condition diagnosis for mass-produced goods such as consumer products and automotive parts. But each diagnostic algorithm must be individually developed for the specific products. So, we developed a diagnostic algorithm-generation method for provision diagnostic algorithms using the AE technique for different kinds of goods. In the method for generating the diagnostic algorithms, we used the following processing steps: extracting a plurality of effective AE parameters for diagnosis by statistical processing; and determining the judgment level for diagnosis with a certainty-factor evaluation method. The method was applied to abnormal sound diagnosis of alternators for automotive products. We developed a suitable diagnostic algorithm, and to date it has provided highly accurate diagnoses in tests.
J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 101
Hayashi, Yoichi; Egawa, Koichi Strain measurement on CFRP filament winding cylinder in wide temperature range (Report 2) In the first report, an easy calculating method for the apparent strain on CFRP filament winding cylinder caused by temperature change of electric resistance strain gauge was suggested, and the results of experiment showed that it has good accuracy and utility for high temperature strain measurement. In this report, the causes of disagreement of the calculated values and measured ones of two gauges out of nine are traced. Five causes are guessed and checked. Finally the cause of trouble is shooted out, that is, the insufficiency of pressure force of the adhering gauges on the test CFRP cylinder.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 41 J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 107
Tayama, Norio; Yang, Xue Dong Non-destructive inspection for 2D smooth density distributions by means of linear programming This paper deals with a theoretical possibility of a new non-destructive inspection method based on an optimum reconstruction from a few selected projections. A theory of optimum reconstruction by a linear programming is discussed, utilizing a few projections for sampled 2D smooth-density-distribution model which satisfies the condition of the sampling theorem. First by use of the sampling theorem, it is shown that we can set up a linear equation system which corresponds to the case of the parallel penetrating beams. Then we solve the linear equation system by means of linear programming algorithm, and we can get an optimum 2D density distribution image with minimum error in the reconstruction. The results of computer simulation with the algorithm are presented.
0963-8695/94/02/0113-01 © 1994 B u t t e r w o r t h - H e i n e m a n n L t d
Yoshida, Hirotaka; Sobue, Kenichi; Masuda, Jun-ichi A study of inspecting strand wires using image processing This paper describes a technique for automatically inspecting strand wires that support telecommunication cables in the air. This technique estimates the degree of corrosion by applying image processing techniques to an image of the strand which is taken by a video camera mounted at the end of a rod held by an inspector who is standing on the ground. The parameters used for judging corrosion are the decrease in strand diameter and the strand's surface texture. We evaluate this technique's utility by testing it on sample and active strand wires. The results show that this technique can judge corrosion as well as skilled inspectors. It gives consistent estimates of the degree of corrosion, eliminates the need for inspectors to work high off the ground, and reduces inspection costs.
NDT&
E International
1994
Volume
27,
Number
2
113
J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 88
Uraoaki, Hiroshi; Hirose, Sadao; Kobayashi, Osamu; Yamamoto, Takehiko
Mihara, Tsuyoshi; Yamada, Yoko; Kanno, Toru
Quantitative analysis of echo amplitude in ultrasonic testing for high attenuation materials using broad band probe A calculation method of a flaw echo amplitude was analyzed about ultrasonic testing for high attenuation materials using a broad band probe. A graphite material was used in this study and its frequency dependency of attenuation coefficient was measured based on the spectrum distributions of multiple bottom echoes. In the results of this experiment, a linear relationship was existing between frequency and attenuation coefficient. The echo amplitude from a flaw can be presented as sum of the echo amplitudes in the each frequency component using the spectrum distribution of the first bottom echo of the calibration block type JIS-STB-A1, which is regarded to be equal to that of the transmitted ultrasonic pulse, and the attenuation coefficient of each frequency component. Calculated value of distance amplitude characteristic curve showed a good correspondence with measured value.
Spectrum analysis of ultrasonic backscattering depending on regularly-arranged microstructural distribution Authors investigate the relationship between spectrum of ultrasonic backscattering signals and microstructures of materials for the basic study of nondestructive evaluation of materials. We propose the simple simulation of backscattered signal spectrum for the qualitative estimation of backscattering in various microstructures. To confirm the availability of the simulation, laminated plate model, regularly-arranged fiber in water model and fiber in resin model are fabricated and the spectrum of backscattered echo of each is measured experimentally. In results, the simulations of the spectrum estimation coincide well to experimental results for all the model specimens. Spectrum of backscattering echo, therefore, could be utilizing to the non-destructive estimation of interval of regulariy-arranged scattering source in materials.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 29 J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 95
Fujisawa, Kazuo; Murayama, Riichi; Yonehara, Sadao; Sakamoto, Haruo Measuring equipment of residual stress in railroad wheel by EMAT Residual stress in the rim of railroad wheel was measured nondestructively by using acoustoelasticity. The propagation time of shear waves polarized in the directions of circumference and radius was measured with Electromagnetic Acoustic Transucer (EMAT) which transmits and receives ultrasonic wave without acoustic couplant. The measuring time was two seconds at each measuring point. The basic experiments showed that the stress was measured with an accuracy of 20 MPa by using EMAT measuring equipment. The field test was also continued for a year to evaluate the residual stress change in the rim of railroad wheels of a locomotive. It is concluded that the residual stress change of the rim is measured with high accuracy by using the EMAT measuring equipment.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 36
Zhano, Yaobano; Sekine, Kazuyoshi; Watanabe, Shinsuke The force on a magnetic particle in the leakage field above the surface-breakingflaw This paper theoretically analyses the magnetic force acting on the magnetic particle in the leakage field caused by surface-breaking flaws. The analysis is based on the modified magnetic dipole model concerning the leakage field, which has been already proposed by the authors. Appropriate analytic expressions have been given to facilitate the numerical computation for the magnetic force of particle. The computed results using the proposed expressions on the magnetic force have been compared with those predicted from the classical dipole model, and there were remarkable differences in the feature of magnetic force distributions between them in the condition of very small lift-off values. As the result of investigation for the characteristics of magnetic force predicted by the present analysis, it was found that the magnetic force attracts the magnetic particles to the neighborhood of the both corners of flaw on the surface, while the classical model shows the attractive force in the direction of the center of flaw top-surface.
Yoneyama, Tokao; Sato, Ichiya; Michimoto, Syozo; Kiguchi, Keichi; Sugiyama, Youichi; Taguchi, Yuji; Yanagibashi, Minoru Generation method of diagnostic algorithms with AE technique for mass produced goods The acoustic emission (AE) technique is a useful means of machine-condition diagnosis for mass-produced goods such as consumer products and automotive parts. But each diagnostic algorithm must be individually developed for the specific products. So, we developed a diagnostic algorithm-generation method for provision diagnostic algorithms using the AE technique for different kinds of goods. In the method for generating the diagnostic algorithms, we used the following processing steps: extracting a plurality of effective AE parameters for diagnosis by statistical processing; and determining the judgment level for diagnosis with a certainty-factor evaluation method. The method was applied to abnormal sound diagnosis of alternators for automotive products. We developed a suitable diagnostic algorithm, and to date it has provided highly accurate diagnoses in tests.
J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 101
Hayashi, Yoichi; Egawa, Koichi Strain measurement on CFRP filament winding cylinder in wide temperature range (Report 2) In the first report, an easy calculating method for the apparent strain on CFRP filament winding cylinder caused by temperature change of electric resistance strain gauge was suggested, and the results of experiment showed that it has good accuracy and utility for high temperature strain measurement. In this report, the causes of disagreement of the calculated values and measured ones of two gauges out of nine are traced. Five causes are guessed and checked. Finally the cause of trouble is shooted out, that is, the insufficiency of pressure force of the adhering gauges on the test CFRP cylinder.
J o u r n a l of J S N D I , Vol. 43, No. 1 ( J a n u a r y 1994) p. 41 J o u r n a l of J S N D I , Vol. 43, No. 2 ( F e b r u a r y 1994) p. 107
Tayama, Norio; Yang, Xue Dong Non-destructive inspection for 2D smooth density distributions by means of linear programming This paper deals with a theoretical possibility of a new non-destructive inspection method based on an optimum reconstruction from a few selected projections. A theory of optimum reconstruction by a linear programming is discussed, utilizing a few projections for sampled 2D smooth-density-distribution model which satisfies the condition of the sampling theorem. First by use of the sampling theorem, it is shown that we can set up a linear equation system which corresponds to the case of the parallel penetrating beams. Then we solve the linear equation system by means of linear programming algorithm, and we can get an optimum 2D density distribution image with minimum error in the reconstruction. The results of computer simulation with the algorithm are presented.
0963-8695/94/02/0113-01 © 1994 B u t t e r w o r t h - H e i n e m a n n L t d
Yoshida, Hirotaka; Sobue, Kenichi; Masuda, Jun-ichi A study of inspecting strand wires using image processing This paper describes a technique for automatically inspecting strand wires that support telecommunication cables in the air. This technique estimates the degree of corrosion by applying image processing techniques to an image of the strand which is taken by a video camera mounted at the end of a rod held by an inspector who is standing on the ground. The parameters used for judging corrosion are the decrease in strand diameter and the strand's surface texture. We evaluate this technique's utility by testing it on sample and active strand wires. The results show that this technique can judge corrosion as well as skilled inspectors. It gives consistent estimates of the degree of corrosion, eliminates the need for inspectors to work high off the ground, and reduces inspection costs.
NDT&
E International
1994
Volume
27,
Number
2
113