-
Yuji NAKASONE
Article type: Article
Pages
301-302
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The present study investigates mesoscopic fatigue deformation behavior of a nodular cast iron via the in-situ observation of mesoscopic structures such as spheroidal graphite inclusions, grain boundaries and multiple small cracks. For this purpose, the in-situ observation system has been constructed by the use of an advanced CCD camera system. The camera system can zoom in on the fatigue-damaged specimen surface at a magnification of up to ×800. The observation reveals that most of the cracks observed starts at the separations of the matrix/graphite interfaces. Incipient cracks grow along gain boundaries; nevertheless, when become larger than, say, 500μm, they begin to grow in the direction perpendicular to the applied strain axis. Coalescence of multiple small cracks often causes the sudden fracture of the specimens. The mesoscopic strain distributions within the observation area were calculated from the change of arbitrary positions of observation on the specimen surface by using the multi-dimensional spline interpolation technique. The result reveals that even under strain-controlled fatigue condition, local strain varies considerably, reflecting damage the material has suffered from mesoscopic defects such as spheroidal graphite, grain boundaries and small cracks.
View full abstract
-
Shinichi SUZUKI, Kenichi SAKAUE, Takahisa MIZUTA, Yasutoshi SASAKI
Article type: Article
Pages
303-304
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Hironori KATO, Hiroshi KATO, Kensuke KAGEYAMA
Article type: Article
Pages
305-306
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Toshihisa NISHIOKA, Motoyuki TAKAGI, Takehiro FUJIMOTO, Keigo SAKAKURA
Article type: Article
Pages
307-308
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Ryuji KOBAYASHI, Hideaki ITO, Tsutomu EZUMI, Susumu TAKAHASHI
Article type: Article
Pages
309-310
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Takashi KUBOKI, Kiyoshi TAKAHASHI, Tetsuya SHINMURA
Article type: Article
Pages
311-312
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Toshiaki HATA
Article type: Article
Pages
313-314
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Daiki SHIOZAWA, Shiro KUBO, Takahide SAKAGAMI, Kousuke OKUNO
Article type: Article
Pages
315-316
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Naoya TADA, Hiroyuki SATOYOSHI, Masaki BANDO
Article type: Article
Pages
317-318
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Fumio TAKEO, Masumi SAKA, Takashi SAGAE
Article type: Article
Pages
319-320
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
A method using more sensitive closely coupled probes for d-c potential drop technique is applied to distinction of alloy steels. The probes are synthesized to build a small sensor. Some alloy steels, which are different from each other in chemical composition, are tested in experiment. A simple equation of the potential drop for an uncracked plate is obtained. Using the equation, the electrical resistivity of the materials is calculated. It is found through multivariate analysis that the resistivity of the alloy steels correlates well with their chemical composition. As a result, it is verified that the closely coupled probes potential drop technique is useful for the evaluation of resistivity in a moment and the distinction of alloy steels.
View full abstract
-
Haoyu Huang, Toshiyuki Takagi
Article type: Article
Pages
321-322
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kiyoshi KOYAMA, Hiroshi HOSHIKAWA
Article type: Article
Pages
323-324
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The conventional eddy current nondestructive testing using pancake probe is prone to suffer from various noise generated by variation of many factors such as probe lift-off and material electromagnetic characteristics. Thus when the conventional eddy current nondestructive testing is applied to maintenance inspection of weld zone, it is difficult to detect the flaw in weld zone because of the noise generated by the shape change and electromagnetic characteristic change of the weld zone. The authors tried the eddy current nondestructive testing of weld zone using uniform eddy current probe that consists of a wide tangential exciting coil and differential tangential detector coils in order to reduce the noise by weld zone. The experimental results have proved that the uniform eddy current probe has a high signal-to-noise ratio compared to the conventional pancake eddy current probe when it is applied to detecting flaws in weld zone.
View full abstract
-
Naoya KASAI, Kazuyoshi SEKINE
Article type: Article
Pages
325-326
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
This paper proposes a quantitative evaluation method for the size of far-side corrosive flaws in steel plates or in pipe-wall by means of the magnetic flux leakage technique. For this purpose, an approach that considers both experimental and theoretical modeling works concerning the simplified model flaws of local corrosion or pitting has been adopted. The experiment has been carried out for steel plate specimens containing artificial flaws with various depths and widths, such as circular holes and rectangular grooves in the backside of specimen plates. These experimental results have suggested that the depth of flaw or residual plate thickness can be estimated by the measurements of strength and distribution of vertical component in magnetic leakage flux density arising from far-side flaws. This is confirmed by analytical model calculations, which have been proposed by the authors concerning far-side magnetic leakage field. Finally, a practical evaluation scheme for size of flaws or residual thickness of metal loss area using this technique has been presented.
View full abstract
-
Takeshi SUZUKI, Atushi YOSHIMURA, Satoshi TANAKA
Article type: Article
Pages
327-328
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Y. SATO, T. SHOJI
Article type: Article
Pages
329-330
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kenichi YAGI, Dorian MINKOV, Kinji TAMAKAWA, Yasumoto SATO, Tetsuo SHO ...
Article type: Article
Pages
331-332
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Yang JU, Masumi SAKA, Hiroyuki ABE
Article type: Article
Pages
333-334
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
A microwave method to measure moisture in encapsulant resin of IC packages was studied. A network analyzer was used to generate a continuous microwave signal fed to an open-ended coaxial line sensor and to measure the amplitude of effective reflection coefficient at the sensor aperture. The coaxial line sensor acted both as a source and receiver of microwave signal, which was transmitted into the encapsulant resin and reflected at the surface of a metallic plate place behind the resin. To evaluate the moisture of encapsulant resin, fundamental experiment was carried out for epoxy resin samples with different moisture contents introduced in various environmental conditions. The relationship between the amplitude of effective reflection coefficient and the moisture content of the encapsulant resin was found, and the evaluation equation was built. The present technique indicates a possibility to determine the moisture in IC packages directly without drying and weighing the package.
View full abstract
-
Yutaka WATANABE, Vivekanand KAIN
Article type: Article
Pages
335-336
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
Electrochemical noise behavior of austenitic stainless steels with various degrees of sensitization was investigated under slow-strain-tensile (SSRT) conditions in a dilute sodium thiosulfate solution. Transition behavior with electrochemical current pulses and corresponding potential fluctuations was detected. Most pulses were detected after yielding point and the frequency of pulse generation gradually increased as strain was increased and finally changed into permanent current mode. A one to one comparison was made between current pulses and surface damages for an interrupted SSRT specimen and a direct correlation was found between a pulse and a crack initiation event.
View full abstract
-
Article type: Appendix
Pages
App8-
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kengo SHIMIZU, Noboru TOMIOKA, Akifumi OKABE
Article type: Article
Pages
337-338
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
Article type: Article
Pages
339-340
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Iton CHOU, Keiji KAMADA, Tadashi KIMURA, Shoichi SAEKI, Kazuo YAMASHIR ...
Article type: Article
Pages
341-342
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Naoki YAMAMOTO, Iton CHOU, Shoichi SAEKI, Kazuo YAMASHIRO
Article type: Article
Pages
343-344
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Masayuki ARAI, Toshio SAKUMA, Uichi IWATA, Masahiro SAITOH
Article type: Article
Pages
345-346
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kunihiko OGINO, Junnji MORIMOTO, Akira OHMORI
Article type: Article
Pages
347-348
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Sang Ok CHWA, Naoki HIRAI, Akira OHMORI, Souta MATSUSAKA, Hui YANG
Article type: Article
Pages
349-350
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
Plasma spraying technique has been widely applied for the production of ceramic protection layer on metals that used in various hostile environments. However, all plasma-sprayed coatings have defects such as connected pores and unmelted particles, which deteriorate coating properties. To improve the properties of these coatings, various post-treatment methods have been reported such as laser irradiation, seal sintering with liquid alloys. Laser irradiation for sprayed coatings is more promising technique than other post-treatment methods due to its efficiency and simplicity. However, it is not easy to produce a uniformly irradiated layer by conventional laser treatment method as desired. To obtain a near-uniform beam intensity for practical laser irradiation, kaleidoscope was installed in a conventional YAG laser and plasma-laser hybrid spraying was tried. In this research, laser beam property of YAG laser equipped with a kaleidoscope and its effect on surface modification of plasma sprayed zirconia coatings was investigated.
View full abstract
-
Takahiro KUBO, Taiji HIRASAWA, Ichiroh KOMURA, Koichiro KAWASHIMA
Article type: Article
Pages
351-352
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Masayuki ARAI, Toshio SAKUMA, Uichi IWATA, Masahiro SAITOH
Article type: Article
Pages
353-354
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
M. Okazaki, T. Suzuki, T. Hiura, K. Nanba
Article type: Article
Pages
355-356
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Hideto SUZUKI, Harukata KUTSUNA, Byungjun LEE, Masaru IKENAGA
Article type: Article
Pages
357-358
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The fatigue property of TiAl intermetallic alloy coated with TiAlN film which changed the film thickness by the physical vapor deposition (PVD) was studied in vacuum at 1073K. The crack initiation and crack growth was observed and photographed under high resolution condition using elevated-temperature loading cyclic stage for the scanning electron microscope. The results indicated that the fatigue strength of 3μm film thickness was most excellent at 1073K. The optimum film thickness reduced plastic deformation and crack initiation in γ phase. Therefore the fatigue property of TiAl alloy which was conducted the optimum film thickness was controlled by meso-structure.
View full abstract
-
Akio FUJI, Masataka YATOMI, Haruki EGUCHI, Chie FUKUOKA, Shigemitsu KI ...
Article type: Article
Pages
359-360
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
Risk-Based Maintenance (RBM) technique has been generated for a 600MW fossil-fired power boiler plant accumulated operating times exceeding 100,000h. The RBM is defined as a multiplication the likelihood of a component failure occurring by the consequence of that failure within semi-quantitative method. That is based on engineering judgment, supported by necessary life assessment. The assessment provides for both the safety and financial risk of failure of each pressure part of the boiler. As a result, the present study shows that the inspection period can be extended from 24 months to 48 months. The RBM technique is an advanced technique to improve maintenance plan of a plant that is considered inspection priority, safety, and cost reduction based on many industrial experiences.
View full abstract
-
Toshimitsu OKANO, Kunihiro YAMADA
Article type: Article
Pages
361-362
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
In this study, fatigue tests were conducted with two types of strain waveform at 700℃. To exclude effect of oxidation environment tests were carried out in vacuum (under 5.3×(10)^<-3>Pa). Used strain waveform were fully reversed triangular form (5.0×(10)^<-3>s^<-1>∿1.0×(10)^<-4>s^<-1>) and slow-fast form (3.3×(10)^<-1>s^<-1>∿3.3×(10)^<-5>s^<-1>). The results obtained are summarized as follows; Fatigue life under slow-fast test were shorter than those under fully reversed triangular test probably because the accumulation of grain boundary sliding displacements became larger than that of the fully reversed triangular form. Under slow-fast tests, an increase in creep effects leads to a shorter fatigue life developing intergranular fracture mode.
View full abstract
-
Tomonori WATANABE, Shigefumi WATANABE, Akitoshi SUZUKI, Tamotsu MAJIMA
Article type: Article
Pages
363-364
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Shinpei FUJIBAYASHI, Takeo OHTUKA, Takao ENDO
Article type: Article
Pages
365-366
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kiyoshi SAITO, Ryoichi KUME, Kazunari FUJIYAMA, Kazunari KIMURA
Article type: Article
Pages
367-368
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Tai ASAYAMA
Article type: Article
Pages
369-370
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kotokaze FURUSAWA, Kastuhiko YASUDA
Article type: Article
Pages
371-372
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Tetsusei KURASHIKI, Masaru ZAKO
Article type: Article
Pages
373-374
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Mitsuo NOTOMI, Hisao HASEGAWA, Haruo SHIMOSAKA, Noburo EHARA
Article type: Article
Pages
375-376
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Tatsumi INOMATA, Toshio SAKUMA, Uichi IWATA, Yasuo OCHI, Shuichi MIYAZ ...
Article type: Article
Pages
377-378
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The shape memory alloy has some useful property. One of the property is the shape memory effect, and the other is the superelasticity (psuedelasticity). These properties are drawn attention from various fields such as the medical, engineering fields and so on. The shape memory alloy is often used under cyclic condition, in this case the degradation of these function is occurred. So, considering the equipments using the shape memory alloy as a element, it is necessary to investigate the degradation property. In this paper, the thermo-mechanical cyclic tests which were combined heating-cooling with loading-unloading for the Ti-41.7Ni-8.5Cu (at%) shape memory alloy were carried out, and the effect of various elements such as the shape memory treatment temperature, the heating temperature, the cold working ratio, and the maximum strain for degradation of functions are investigated experimentally.
View full abstract
-
[in Japanese], [in Japanese]
Article type: Article
Pages
379-380
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Xia ZHU, Nagatoshi OKABE, Miyoshi TSUTSUMI
Article type: Article
Pages
381-382
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kazushi HARUNA
Article type: Article
Pages
383-384
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
Diffusion of water into adhesives cause to reduce the strength of the bonded structures. In case of optical devices, a problem in the use of adhesive bonding has been its propensity to absorb moisture and swell. A practical and accurate method of predicting moisture absorption and its effects is essential. In this study, deformation generated by humidification and dehumidification was monitored by using the bimetal specimen. 2-part room temperature cured epoxy adhesive and copper substrate were used. Temperature on the surface of adhesive keeps at a fixed temperature and humidity was synchronized with laboratory environment. It was cleared that deformation was proportional to relative humidity. Moreover, time dependent distribution of moisture in a adhesive was calculated by the Fickean diffusion law and deformation was calculated by the Hook's law and the coefficient of moisture expansion (CME). There is good agreement between experimental and calculated results.
View full abstract
-
Akira TANAKA, Takao INUKAI, Akira NEMOTO, Kazunari FUJIYAMA, Yoshiyasu ...
Article type: Article
Pages
385-386
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Qiang YU, Youko BANDOU, Ryouhei TAKEUCHI, Hiroyuki ISHIKAWA, Masaki SH ...
Article type: Article
Pages
387-388
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Naoki MIURA
Article type: Article
Pages
389-390
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The prediction of crack opening behavior for cracked pipes subjected to an actual loading is essential to prove the Leak-Before-Break concept for Light Water Reactor piping. The pressure loading under the normal operating condition induces bending moment due to the eccentricity of the neutral axis from the pipe centerline. The current crack opening behavior is analyzed for a cracked pipe element that allows free rotation at the ends of the pipe. Considering a boundary condition of real piping system, however, the ends of the pipe will be restrained from free rotation. And the amount of the restraint will affect the carack opening displacement. In this paper, the effect of the restraint on the crack opening displacement of the cracked pipes is analytically examined.
View full abstract
-
Izumi NAKAMURA, Nobuyuki OGAWA, Akihito OTANI, Kotoji ANDO
Article type: Article
Pages
391-392
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Musashi YAKURA, Masaki SHIRATORI, Nagahisa OGASAWARA, Izumi NAKAMURA, ...
Article type: Article
Pages
393-394
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
The purpose of the study in this paper is to establish analytical approaches by which the failure behaviors of the locally thin-walled piping can be simulated well against seismic loading. The summary of results obtained through the present study is as follows. Fully three dimensional elasto-plastic analyses have been carried out for the locally thin-walled piping by using ABAQUS. It has been found that the ratcheting behavior observed in the experiment can be simulated well through the finite element analysis.
View full abstract
-
Hiroshi OHYA
Article type: Article
Pages
395-396
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Koichi SAITO, Shizuka SHIMANUKI, Jiro KUNIYA, Masami ANDOU, Takahiko K ...
Article type: Article
Pages
397-398
Published: October 05, 2000
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
FREE ACCESS
In the case of non-cold-worked type 304 stainless steel, stress corrosion crack growth rate of miniature round compact tension specimen was much higher than one of I-inch compact tension specimen and specimen size effect was observed. From the results of elastic-plastic fracture mechanics analysis, it was indicated that SCC growth rate tends to increase with increasing normalized equivalent plastic strain at the crack front, regardless of specimen shape or size and cold-work conditions.
View full abstract