http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Inference of Plastic Deformation in Weldment with Parallel Cracks from Infrared Thermography
Tanaka, Yuichi,Oda, Isamu,Nakano, Akira,Murao, Yuji 대한금속재료학회(대한금속학회) 1998 METALS AND MATERIALS International Vol.4 No.3
Tensile tests are carried out by using the welded plate with two parallel cracks. The effects of the residual stress, the hardened zone by welding and the interaction between cracks on the plastic deformation near cracks and the crack opening displacement are examined by the experiment as well as the elasto plastic finite element analysis. A new technique for evaluating nondestructively the plastic deformation near cracks by using the infrared thermography is proposed. The heated region and the temperature rise measured by the thermography are compared with the plastic zone and the work of plastic deformation obtained by the analysis. The validity and the limitations of the application of the infrared thermography to the evaluation of the plastic deformation are discussed.
Deformation near Parallel Cracks Close to Interface in Bonded Dissimilar Plate
Tanaka, Yuichi,Oda, Isamu,Yamamoto, Mitsuharu 대한금속재료학회(대한금속학회) 1998 METALS AND MATERIALS International Vol.4 No.3
Tensile tests are carried out by using rectangular plate specimens extracted from the explosion clad plate. Artificial parallel cracks are made perpendicularly to the explosive interface in each specimen. When a tensile load is applied perpendicularly to the crack plane, strain, plastic deformation near cracks and crack opening displacement are examined by experiments as well as elasto-plastic finite element analysis. The effects of the material inhomogeneity, the change of material characteristics, the residual stress and the interaction between parallel cracks on the deformation behavior are revealed. The plastic zone around parallel cracks, at relatively low applied stress level, grows mainly ahead of and between two cracks. The interaction between parallel cracks on the crack opening displacement can be explained from the square of stress intensity factor at the low applied stress level and from the plastic deformation at the high applied stress level.
Oki, Yuichi,Tanaka, Toru,Takamiya, Koichi,Osada, Naoyuki,Nitta, Shinnosuke,Ishi, Yoshihiro,Uesugi, Tomonori,Kuriyama, Yasutoshi,Sakamoto, Masaaki,Ohtsuki, Tsutomu The Korean Association for Radiation Protection 2016 방사선방어학회지 Vol.41 No.3
Background: Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. Materials and Methods: A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of $^{11}C$-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. Results and Discussion: The size distribution for $^{11}C$-bearing aerosol particles was found to be ca. $70{\mu}m$ in geometric mean diameter. The size was similar to that for $^7Be$-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. Conclusion: The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.
Attachment Behavior of Fission Products to Solution Aerosol
Takamiya, Koichi,Tanaka, Toru,Nitta, Shinnosuke,Itosu, Satoshi,Sekimoto, Shun,Oki, Yuichi,Ohtsuki, Tsutomu The Korean Association for Radiation Protection 2016 방사선방어학회지 Vol.41 No.4
Background: Various characteristics such as size distribution, chemical component and radio-activity have been analyzed for radioactive aerosols released from Fukushima Daiichi Nuclear Power Plant. Measured results for radioactive aerosols suggest that the potential transport medium for radioactive cesium was non-sea-salt sulfate. This result indicates that cesium isotopes would preferentially attach with sulfate compounds. In the present work the attachment behavior of fission products to aqueous solution aerosols of sodium salts has been studied using a generation system of solution aerosols and spontaneous fission source of $^{248}Cm$. Materials and Methods: Attachment ratios of fission products to the solution aerosols were compared among the aerosols generated by different solutions of sodium salt. Results and Discussion: A significant difference according as a solute of solution aerosols was found in the attachment behavior. Conclusion: The present results suggest the existence of chemical effects in the attachment behavior of fission products to solution aerosols.
Bending fatigue strength of case-carburized helical gears with large helix angles up to 40 degrees
Mikiya Yamaoka,Motomu Tanaka,Masaya Kumada,Kengo Nojima,Ryosuke Nishi,Yuichi Ono,Takao Koide 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.12
Case-carburizing of helical gears with large helix angles may form too large hardened layers near the tooth width end on the acute angle side (ACUTE-END), and adversely affect the bending fatigue strength. We investigated the bending fatigue strength of casecarburized helical gears with large helix angles up to approximately 40° through a bending fatigue test, hardness test, and residual stress measurement. We found that the case-carburizing formed large hardened layers near ACUTE-END, reduced the compressive residual stress near ACUTE-END, and restricted the improvement of the bending fatigue strength in a meshing state where tooth root stress became large near ACUTE-END. Based on the obtained bending fatigue limits, we revealed that ISO 6336-3:2006 overestimated the rate of increase of the permissible circumferential loads for helix angles exceeding approximately 30°, and ISO/DIS 6336-3:2018 underestimated this rate for helix angles near 30°.