著者

中山 英明 田中 道七 山元 茂 村田 隆行

出版者

公益社団法人 日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.41, no.466, pp.1040-1046, 1992-07-15 (Released:2009-06-03)

参考文献数

26

被引用文献数

1

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Recently, reliability assessment on the micro-joining for electronic apparatus attracts major attention of engineers and researchers in this field. Failure problems of the micro-joining have to be investigated from an interdisciplinary point of view, for the failure phenomena are caused not only by a mechanical effect but also by a metallurgical and/or electrochemical effect. For example, construction of brittle intermetallic compounds at Au wire/Al pad interface of ball bonding is a problem of metallurgical aspect, and electro-migration induced between soldering parts on high density printed circuit board is problem of electrochemical aspect. Though there are several micro-joining methods such as thermo-compression, ultrasonic bonding, micro-soldering and so on, a majority of micro-joining applied in electronic apparatus is micro-soldering. Therefore, it is an urgent problem to establish a valid evaluation method for solder joint performance under service conditions. A typical problem on this point is the solder cracking induced by temperature cycling, depending on the mismatch of thermal expansion coefficients of structural elements. In order to clear the failure problem of solder joint, fatigue failure mechanism of solder itself must be systematized.The main purpose of the present study is to investigate the fatigue strength and strain behaviors of 60Sn/40Pb solder plate specimen under several repeated load conditions including impact load carried out at room temperature. And furthermore, room temperature creep tests were also carried out to discuss the correlation between cyclic fatigue and static fatigue of the solder.The results of this study revealed a clear dependence of the fatigue life on the stress patterns; the lower was the frequency of stress cycle the lower was the fatigue strength. And the strength in impact fatigue showed the highest value. Then, the evaluation from the viewpoint of cumulative loading time indicated that the fatigue life of the solder could be well estimated by the cumulative loading time regardless of the type of stress pattern. And furthermore, the relationship of the stress vs. the cumulative loading time in cyclic fatigue well coincided with the creep rupture curve.

著者

中山英明 細田暁 川邉翔平 長谷川雄基

雑誌

コンクリート工学年次大会2021(名古屋)

巻号頁・発行日

2021-07-05

著者

蟹江 康光 服部 陸男 中山 英明 関 邦博 水嶋 康男 設楽 文朗 伊藤 信夫

出版者

日本貝類学会

雑誌

貝類学雑誌 (ISSN:00423580)

巻号頁・発行日

vol.40, no.2, pp.86-94, 1981-07-15 (Released:2018-01-31)

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In a hyperbaric chamber, living mature specimens of Nautilus pompilius withstood the hydrostatic pressure of 8.31 MPa (84.7 kg/cm^2) equipvalent to 827 m-depth in the sea and 7.89 MPa (80.5 kg/cm^2) equivalent to 785 m-depth, respectively, before it was killed instantly by implosion, the animals reacted physiologically to increasing pressure including increased partial pressure of oxygen with the compression rate (0.0981 MPa/min). This suggests that Nautilus undergoes severe stress during rapid descent and ascent through the water column. The shell implosion was caused by maximum strain-shortening (1.3% of the length). The shell implosion under pressure seems to have occurred at an old air chamber or siphuncular tube but not at the last septum of the phragmocone. Consequently, the depth of approximately 800 m is considered to be the maximal depth that N. pompilius is durable. The result will be usable for interpretations on paleobiology of extinct nautiloids and ammonoids which have similar shells and siphuncular tube system as living Nautilus.

著者

堀川 教世 中山 英明 境田 彰芳 田中 道七

出版者

公益社団法人 日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.49, no.4, pp.426-432, 2000-04-15 (Released:2009-06-03)

参考文献数

12

被引用文献数

3 3

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Load-controlled fatigue tests were carried out on PAN-based monofilament carbon fibers under cyclic tensile load conditions at a frequency of 10Hz. Fatigue strength data are obtained under pre-determined maximum load Pmax with three different stress ratios of R(=Pmix/Pmax)=0.1, 0.5 and 0.7. The maximum load Pmax is not an appropriate parameter to evaluate the fatigue strength behavior because the cross-sectional area of monofilament carbon fiber is not constant and varies along the longitudinal direction. This fact results in a large scatter of fatigue lives when the data are plotted on Pmax-Nf diagram. In order to evaluate the fatigue strength behavior more precisely, the fatigue strength data must be plotted on S-N diagram by using the maximum tensile stress σmax determined from the cross-sectional area of the fracture surface. It is found that S-N properties of monofilament carbon fibers clearly show the fatigue behavior, depending on the stress ratio R. It is also found that the fatigue strength of monofilament carbon fiber is governed by two parameters such as the maximum stress σmax and the stress amplitude σa, and that the combined stress parameter σmax(1-α)×σaα is useful to describe the fatigue strength behaviors of the different stress ratios.

著者

堀川 教世 中山 英明 境田 彰芳 田中 道七

出版者

社団法人日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.49, no.4, pp.426-432, 2000-04-15

被引用文献数

2 3

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Load-controlled fatigue tests were carried out on PAN-based monofilament carbon fibers under cyclic tensile load conditions at a frequency of 10Hz.Fatigue strength data are obtained under pre-determined maximum load P_max with three different stress ratios of R(=P_mix/P_max)=0.1, 0.5 and 0.7.The maximum load P_max is not an appropriate parameter to evaluate the fatigue strength behavior because the cross-sectional area of monofilament carbon fiber is not constant and varies along the longitudinal direction.This fact results in a large scatter of fatigue lives when the data are plotted on P_max-N_f diagram.In order to evaluate the evaluate the fatigue strength behavior more precisely, the fatigue strength data must be plotted on S-N diagram by using the maximum tensile stress σ_max determined from the crosssectional area of the fracture surface.It is found that S-N properties of monofilament carbon fibers clearly show the fatigue behavior, depending on the stress ratio R.It is also found that the fatigue strength of monofilament carbon fiber is governed by two parameters such as the maximum stress σ_max and the stress amplitude σ_a, and that the combined stress parameter σ_max~(1-α)×σ_a~α is useful to describe the fatigue strength behaviors of the different stress ratios.