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Yasuji YAMAGISHI, Hirakazu KASUYA
Article type: Article
Pages
459-460
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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This paper deals with the problem of dynamic stability of composite laminated cylindrical shells under impact hydrostatic pressure is described. First of all, the motion of cylindrical shells under impact hydrostatic pressure is defined as axially symmetric motion. Following this definition, certain perturbations are superimposed on this motion and their effect on the behavior of the shell is investigated. The symmetric state of motion of the shell is called stable if the perturbations remained bounded. The solutions for the prebuckling motion and the perturbed motion are obtained using the Galerkin's method. Stable regions are determined by utilizing Mathieu's equation. The inevitability of dynamically unstable behavior is proved analytically and the effects of various factors, such as hydrostatic pressure ratio, lamination angle and dynamic unstable mode, are clarified.
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Ken MIYAUCHI, Yuichiro YAMAMURA, Masahiro FUJII, Hiroshi FUJINO, Shuni ...
Article type: Article
Pages
461-462
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Masahiro ISHIHARA, Tsuneo TAKAHASHI, Satoshi HANAWA
Article type: Article
Pages
463-464
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Kotokaze FURUSAWA, Kotoji ANDOU, Naoki FURUMACHI, Sigemi SATOU
Article type: Article
Pages
465-466
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Koji TAKAHASHI, Kotoji ANDO, Shin NAKAYAMA, Shinji SAITO
Article type: Article
Pages
467-468
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Hirokazu TANAKA, Mototsugu TANAKA, Masaki HOJO, Shojiro OCHIAI
Article type: Article
Pages
469-470
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Tsuyoshi Ozaki, Hirotsugu Morinaga, Hidetaka Ishii
Article type: Article
Pages
471-472
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Recently carbon composites are being applied to space structures used under cryogenic temperature such as infrared space telescopes or propulsion tanks. To use carbon composite at cryogenic temperature, methods to evaluate material properties at cryogenic temperature are needed. In order to measure the thermal expansion of carbon composite in cryogenic temperature, a method using optical heterodyne interference was developed. Using this method, thermal expansion of two types of carbon composites were measured at cryogenic temperature lower than 10K.
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Dong mei Luo, Shigeo Takezono, Katsumi Tao
Article type: Article
Pages
473-474
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Article type: Appendix
Pages
App23-
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Kohhei TANAKA, Toshio HATTORI, Akira KITAJIMA
Article type: Article
Pages
475-476
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Masaaki IWASA, Toshio HATTORI
Article type: Article
Pages
477-478
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Kazuhiro ODA, Takahiro NAKAYAMA, Nao Aki NODA, Dai Heng CHEN
Article type: Article
Pages
479-480
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Yuji Sano
Article type: Article
Pages
481-482
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
Pages
483-484
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Inami KAZUNORI, Toshihiko YOSHIMURA, Ren MORINAKA, Noboru SAITO
Article type: Article
Pages
485-486
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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The Water Jet Peening (WJP) is a well-known method to reduce residual stress. The size of peening marks formed by WJP with a few micrometer is so small, although the high residual compressive stress is obtained on the material surface. This means that WJP is a mild surface treatment. It is found that the extreme values statistical analysis is effective to estimate the maximum size of peening marks by WJP and the collapse pressure of cavitations.
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Koji YAMADA, Bing Liu, Akiyoshi Shinagawa
Article type: Article
Pages
487-488
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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The Magnetic diagnosis of leakage flux of materials is performed by using a new type fluxgate sensor operated by differential magnetic circuit. The sensor is sensitive only for the local field and insensitive against the Geomagnetism. We attained a sensitivity of about lmOe full scale with an 1% accuracy and applied to Nondestructive evaluation of magnetic steels as SUS304,A533B and S25c, where the intensities of the first derivative is reversed proportional for paramagnetic material of SUS304 due to induced martensitic transformations and positively proportional for ferromagnetic materials of A533B and S25C.
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Tokuo TERAMOTO, Takashi DOI
Article type: Article
Pages
489-490
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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In this study, the method of eddy current testing was applied to the detection of material degradation according to plastic strain and following martensitic transformation of SUS304. The change of coil impedance was found especially large during yielding process. Although the impedance showed a significant change across the notch line, less change was found if low AC frequency was used in LCR measuring. We conclude that the coil impedance is revealed useful for detecting the material degradation of SUS304.
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Mohachiro OKA, Terutoshi YAKUSHIJI, Yuji TSUCHIDA, Masato ENOKIZONO
Article type: Article
Pages
491-492
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Yuji NAKASONE, Tetsu SHIMIZU, Soji KASUMI
Article type: Article
Pages
493-494
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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The present study has investigated plasticity-induced martensitic phase transformation in fatigue of welded SUS304 plates. Martensitic phase transformation occurred in welded SUS304 plate specimens fatigued at room temperature in air. Ferrite scope reading of the central potion of welded specimens ranged 10 to 15%, indicating the existence of ferromagnetic ferrite phase produced during the welding process. Modified ferrite scope reading ζ, 1.37 times ferrite reading, showed a slight decreased after the application of cyclic stress, then remained almost a constant value of 15 to 17% irrespective of applied stress range Δσ for the most part of fatigue life, and finally showed sudden increased to about 28% to cause fracture. The spatial distribution of ζ in the welded specimens varied with the number of load cycles N : i.e., continued cycling of stress made α' transformation localized near the central portion of specimens where the ζ value reached as high as 18-21%. This value is higher than the highest ζ_<α'> value found in the tensile tests of SUS304 at room temperature. Small edge cracks were found in the high ζ value regions of the welded SUS304 specimens. These results imply that the measurement of ζ in fatigued SUS304 weldments can detect crack initiation sites and predict residual fatigue life.
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Shigeru TAKAYA, Takayuki SUZUKI, Yoshihiro MATSUMOTO, Kazuyuki DEMACHI ...
Article type: Article
Pages
495-496
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Daiki SHIOZAWA, Shiro KUBO, Takahide SAKAGAMI, Syunsuke OKAZAKI
Article type: Article
Pages
497-498
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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When a piezoelectric film is glued on the surface of a cracked structure subjected to load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for identifying two- and three-dimensional cracks. In this study, this method was applied to identify experimentally a three-dimensional crack opening on the back surface. Electric potential distribution on the piezoelectric film mounted on the front surface was measured by non-contact voltmeter. Measured electric potential distribution agreed well with that calculated by the FEM. The inverse method based on the least residual method was applied for estimating the location and size of crack from the measured electric potential distribution. It was shown that the passive electric potential CT method using piezoelectric film was useful for quantitative identification of back-surface three-dimensional crack.
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Naoya TADA, Masayoshi OKADA
Article type: Article
Pages
499-500
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Noritaka YUSA, Zhenmao CHEN, Kenzo MIYA, Tetsuya UCHIMOTO, Toshiyuki T ...
Article type: Article
Pages
501-502
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Tetsuya UCHIMOTO, Makoto KUROSAWA, Toshiyuki TAKAGI, Sergiy KONOPLYUK, ...
Article type: Article
Pages
503-504
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Masumi SAKA, Yasuhiro UCHIMURA
Article type: Article
Pages
505-506
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Article type: Appendix
Pages
App24-
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Naoyuki KOUNO, Masahiro KOIKE, Takao SHIMURA
Article type: Article
Pages
507-508
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Non-destructive evaluation techniques have become more important for high reliability of power plant structures. For the weld zone of austenitic materials, e.g., austenitic stainless steel and nickel-based alloy, fully effective ultrasonic inspections are difficult due to beam skewing and attenuation arising from its complex acoustical anisotropy. In order to evaluate the acoustical characteristics of austenitic steel, velocities of ultrasonic wave are measured for single crystals of nickel-based alloy and directionally solidified alloy. Measurement values of velocities agree with numerical results based on the transversely isotropic model, which is based on the assumption of random orientation distributions around the solidification axis <100>, with an accuracy of about 3%.
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Hirotsugu INOUE, Takuro ASAOKA, Kikuo KISHIMOTO
Article type: Article
Pages
509-510
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Seiichi NISHINO, [in Japanese], Kazuaki SHIOZAWA, Hiroyuki SHINJIN, Yo ...
Article type: Article
Pages
511-512
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Yoshikazu OHARA, Sanae HANAOKA, Koichiro KAWASHIMA, Norimitsu HIROSE
Article type: Article
Pages
513-514
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Masaki YAMADA, Kazuyuki NAKAHATA, Michihiro KITAHARA
Article type: Article
Pages
515-516
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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A linearized inverse scattering method is applied to the reconstruction of a damaged part in the interface of materials. In this study, cement-based material with a reinforcing steel bar is prepared, where a damaged part exists on the interface of the steel bar and cement-based materials. The experimental measurement is performed and it is shown that the linealized method reconstructs the part of imperfections on the interface.
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Tsuyoshi Mihara, Shinji Nomura, Masashi Akino, Kazushi Yamanaka
Article type: Article
Pages
517-518
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Takeru OKUMURA, Masami SATO, Koichiro KAWASHIMA
Article type: Article
Pages
519-520
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Hironori TOHMYOH, Masumi SAKA
Article type: Article
Pages
521-522
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Yutaka WATANABE, Keisuke SATO
Article type: Article
Pages
523-524
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Yutaka Watanabe, Yuzo Daigo, Hiroto Tamura, Tetsuya Uchimoto
Article type: Article
Pages
525-526
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Takumi YAMAMOTO, Kimio WATANABE, Tetsuo SHOJI
Article type: Article
Pages
527-528
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Masatoshi TANNO, Kazuhiro OGAWA, Tetsuo SHOJI, Song Ok CHWA, Akira Omo ...
Article type: Article
Pages
529-530
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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It is well known, that thermally grown oxide (TGO) is formed at an interface of thermal barrier top coating (TBC) and bond coating during service. In the previous work, TGO layer contained at least two layers with different oxides was observed by SEM images. One was Al_2O_3,and the other was mixed oxide of NiO, CoO, Cr_2O_3,or their spinels. It was supposed that a formation of pores in the mixed oxide caused a decrease in bond strength or a formation of stress concentration site. In order for an improvement of oxidation resistance of TBC, plasma sprayed bond coating was remelted by YAG laser before spraying of top coating. Isothermal oxidation test was carried out at 1000℃, as a result of SEM observation and XRD, ESCA analysis, the mixed oxide formation decreased as compared with conventional one.
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Article type: Appendix
Pages
App25-
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Kyotaro YOSHINO, Masakazu INABA, Toshimitsu FUJISAWA, Genki YAGAWA
Article type: Article
Pages
531-532
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Akiyuki Takahashi, Naoki Soneda, Genki Yagawa
Article type: Article
Pages
533-534
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Dislocation structure formation is one of important mechanisms in the work hardening process of metals. The formation of dislocation dipoles an cross slip plays and important role in the dislocation structure formation. In this study, three dimensional dislocation dynamics simulation of dislocation motions in a body centered cubic crystal was performed with a rule for cross slip. The rule was considered as a thermal activation process by using Boltzman factor in the simulations, and the cross slip event is determined by probabilistic approach. In the simulations, one small Frank-Read source can glide on their own slip plane under given loading condition, and the amount of dislocation density in the computation box can effectively increase due to the cross slip mechanism.
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Akira MIKI, Shogo IMAMURA, Shigetoshi ARAKI
Article type: Article
Pages
535-536
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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The stress intensity factor of an elliptic toroidal crack which consists of the nested sequence of two elliptics is caluculated by using the finite element method. The three dimensional isoparametric singular elements are used for taking into consideration the singulality of strain at the tip of such a crack, and they are arranged so as to surround the crack tip. In element subdivision, the geometry of the singular element whose edge corresponds to the crack front is designed to be a fan on the crack surface. Namely, the corner angle of the singular element is designed to be right. It can be seen from numerical results that the value of the stress intensity factor at the inner tip of the elliptic becomes always greater than that at the outer tip and its maximum value occurs at the crack tip on major axis of the inner elliptic. Therefore, the inner elliptic of the elliptic toroidal crack is considered to propagate to be circular.
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Keisuke KATAYOSE, Noriyo HORIKAWA, Takayuki KUSAKA
Article type: Article
Pages
537-538
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Nagahisa Ogasawara, Yuuki Kitayama, Norimasa Chiba, Masaki Shiratori, ...
Article type: Article
Pages
539-540
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Noriyuki KUSHIDA, Hiroshi OKUDA, Genki YAGAWA
Article type: Article
Pages
541-542
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Kazushi HARUNA, Hiromi Itoh, Toshiharu Andoh
Article type: Article
Pages
543-544
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
Pages
545-546
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Takayuki KUSAKA, Taketoshi NOJIMA, Atsushi YUTA
Article type: Article
Pages
547-548
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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Hidetoshi KOBAYASHI, Masashi DAIMARUYA
Article type: Article
Pages
549-550
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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In this research, the unfolding manner of morning glory flowers was studied as a good example of interesting folding patterns in nature. Using a video camera, the unfolding of morning glory flowers was observed. From the observation, the deploying radius of flowers was measured and the radius-time curves were obtained. The force and the energy required for deploying petals were estimated using a number of models with different deploying manners. In order to obtain the mechanical properties of flower materials, tensile tests were also performed.
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Masaki FUJIKAWA, Masahisa TAKASHI
Article type: Article
Pages
551-552
Published: October 10, 2002
Released on J-STAGE: August 01, 2017
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It is important to analyze meshing behavior and the variation of contact ratio in Plastic Spur Gear for the estimation of power transmission error, tooth wearing and noise increase. The experimental method for follow the tracks of contact in gears, however, has not been established experimentally. As a purpose of this study, the authors try to analyze the tracks of contact and the real contact ratio in a pair of Plastic Spur gears in a frame work of FEM analysis. Then, the authors propose a formula taking the variation of real contact ratio into account. Comparison of the proposed formula with the result of FEM analysis, showed good agreement each other.
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