著者
張 学超 森 敬祐 真壁 朝敏 井上 晋一 安藤 新二
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.70, no.6, pp.473-478, 2021
被引用文献数
1

<p>Push-pull fatigue tests of rolled magnesium alloys AZ31 and AZX912 were performed with a side-notch plate specimen to examine the effect of a single overload on the crack growth behavior under a stress ratio of -1. The behavior in retardation of crack growth was unclear in the case of AZ31 because the crack growth rate was relatively higher at the overload point. However, this was observed clearly, when the branching of the crack tip happened in the case of AZX912. The geometry of the fracture surface and the changes in crack growth path were related to the crack growth behavior. The crack opening level became higher when the crack growth rate was lower. Therefore, the crack closure is related to the retardation of the crack growth rate. When the branching of a crack tip occurred, not only the residual compression stress at crack front but also the variation of local crack growth direction after overload affected the fatigue crack growth behavior. </p>
著者
西野 孝
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.57, no.1, pp.97-103, 2008 (Released:2008-01-20)
参考文献数
26
被引用文献数
3 4
著者
矢野 浩之
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.46, no.8, pp.996-1002, 1997-08-15 (Released:2009-06-03)
参考文献数
43
被引用文献数
1
著者
遠藤 和人 中川 美加子 肴倉 宏史 井上 雄三 井 真宏 杉原 元一
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.61, no.1, pp.31-36, 2012-01-15 (Released:2012-01-20)
参考文献数
8
被引用文献数
1

Necessity to promote a recycle of waste plaster board is mounting, since the waste plaster board has been legally prohibited to dispose into inert landfill site. However, it is concerned that the recycled waste plaster board (recycled gypsum) produces hydrogen sulfide gas, so that it is one of the interference with the recycling. There is a possibility to control the hydrogen sulfide gas production from the recycled gypsum by artificially changing into alkaline condition or adding iron oxide. In this study, we discussed the hydrogen sulfide gas production from a ground improvement with the recycled gypsum, quick lime, and/or iron oxide powder. In addition, unconfined compression strength of the ground improvement is evaluated in order to obtain an incentive of the recycling. Adding only the recycled gypsum cannot improve strength of a soft ground having much amount of fine particles. Quick lime was required for strength improvement. If pH of the ground improvement is greater than 9, it was observed that the hydrogen sulfide gas production potential is negligible. Increasing pH by adding the quick lime is able to more effectively control the production of the hydrogen sulfide gas than adding the iron oxide powder. The production of the hydrogen sulfide gas is able to be controlled by adding the quick lime more than half of the amount of gypsum addition.
著者
進藤 明夫
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.27, no.296, pp.401-415, 1978-05-15 (Released:2009-06-03)
参考文献数
160
著者
鎌田 浩毅 須田 恵理子 齋藤 武士 飯澤 功 酒井 敏
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.51, no.2, pp.168-175, 2002-02-15
参考文献数
28

Volcanic debris avalanche is a large-scale landslide which occurs at unstable volcanic edifice and often creates horseshoe-shaped crater at its source with hummocky deposits of volcanic debris including large blocks inside. Dynamic pressure model has recently been proposed to explain flow behavior of volcanic debris avalanches: Kinetic friction of debris avalanche decreases systematically at threshold of a certain critical speed for flotation. We have done a sliding experiment using flour powder as debris avalanche matrix and metal disks that slide on a powder layer as incorporated large blocks. Sliding traces left on a powder layer showed that a disk was floating over a certain critical speed. Kinetic friction coefficients, calculated by the position of a sliding disk recorded on a digital video, become small at a higher speed which exceeds critical floating speed, and provide smaller coefficient than those of normal surface of a rigid body. The critical floating speed deduced from dynamic pressure model is consistent with our experiment. In order to verify this model as the major driving force to float megablocks incorporated commonly in a volcanic debris avalanche, critical floating speeds for two geological cases at the collapses of 1980 Mount St. Helens and 1984 Ontake, central Japan, are examined and compared with the observed flow velocities. Estimated velocities deduced from the dynamic pressure model correspond fairly well to the actual velocities. This strongly suggests that the model gives the most convincing explanation for transportation and deposition mechanism of volcanic debris avalanche.
著者
池田 豊
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.17, no.182, pp.979-989, 1968-11-15 (Released:2009-06-03)
参考文献数
50
被引用文献数
1 1
著者
宮本 昭彦 村上 敬宜
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.47, no.8, pp.830-835, 1998-08-15 (Released:2009-06-03)
参考文献数
7
被引用文献数
1 1

On crime scenes, plate glass is frequently shot by bullets. The fracture of plate glass by a pachinko ball (steel ball) impact also occurs. Experiments were carried out to obtain basic data for estimating the impact velocities of projectiles from the morphology of the fracture. Projectiles {11mm dia. steel balls and 0.38 inch (9mm dia.) lead bullets} were shot onto ordinary glass plates firmly held around a circular periphery.It was assumed that projectile kinetic energy would all be converted into surface energy of fractured glass. The relationship between crack area Af and kinetic energy of projectiles was investigated. A strong experimental correlation was found between Af and the change in kinetic energy. A unique relationship was obtained between crack area and energy consumed during fracture regardless of the projectile material (steel and lead).
著者
仲村 匡司 坂井 崇俊 増田 稔
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.51, no.4, pp.398-403, 2002-04-15
参考文献数
16
被引用文献数
1 4

Visual characteristics of wood which influence visual hardness of it were studied. Thirty-four photographs of H-shaped wooden backs of chairs were prepared as specimens. Questionnaires regarding visual hardness and &ldquo;deluxe&rdquo; image of specimens were distributed to 32 subjects using the repeated equal-division method. Color values (<i>Y, x</i> and <i>y</i>) of specimens were measured by the colorimeter. Local-area gloss <i>G</i> and spatial ratio of contrasts <i>C</i> were calculated using digital image analyses. <i>G</i> was the index of the local-area glossiness (highlight), and <i>C</i> was the index of the noticeability of wood grain figures. Calculation procedures for both indices were newly developed in this paper. The single correlation coefficient between a visual &ldquo;hard&rdquo; image and <i>Y</i> (lightness of specimen) was -0.91, and that between <i>G</i> was 0.83. Using visual &ldquo;hardness&rdquo; as a criterion variable and <i>Y</i> and <i>G</i> as predictor variables, a multiple regression analysis was performed. The multiple correlation coefficient was 0.931, the ratio of contribution was 86.7% (significant level 1%). Furthermore <i>C</i> was added to the regression model, above values were 0.942 and 88.8%, respectively (significant level 1%).
著者
北川 浩
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.28, no.307, pp.339-344, 1979-04-15 (Released:2009-06-03)
参考文献数
13
著者
丹羽 雅子
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.22, no.236, pp.383-391, 1973-05-15 (Released:2009-05-26)
参考文献数
37
被引用文献数
1 1

In textile industry, performance of the fabrics is still out of the engineering design, because of the difficulty in designing the proper mechanical properties of fabrics, and also of the difficulty in evaluating the performance where the evaluation has been done by a sensory method named "hand-feel" by experts.In this article, recent developments in the theoretical research on the mechanical properties of fabrics are introduced. Theoretical methods of calculating the non-linear property in biaxial and uniaxial tensile deformations of plain woven, plain knitted and inter-lock fabrics are presented here. And bending and shear properties of plain woven fabrics are also dealt with.Furthermore, a new method for evaluating "hand-feel" is introduced; the mechanical properties of fabrics are first characterized and represented by sixteen number of characteristic values obtained by the measurements of mechanical, physical and geometrical properties of the fabrics, and then using a linear model, the "hand-feel" value is calculated from these characteristic values. The agreement between the conventional sensory and the new instrumental methods is demonstrated.
著者
吉川 敬治 加藤 寛 星野 光男
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.35, no.399, pp.1431-1437, 1986-12-15 (Released:2009-06-03)
参考文献数
14

Hardness of carbon fiber reinforced plastics (CFRP) and Al-2 and 4wt% Cu alloys containing columnar grains was measured with a wedge-shaped indenter, and was compared with their static tensile properties. Hardness measurement was conducted with a Rockwell hardness tester. The hardness and mean pressure of CFRP decreased with the angle θ between indentation normal and fiber direction. The orientation dependences of the hardness and the mean pressure agreed with those of Young's modulus and the fracture strength of CFRP. However, no linear relation existed between the mean pressure and the strength. The hardness and the mean pressure of Al-Cu alloys took a minimum when the angle θ was about π/4 rad, and the orientation dependence of the mean pressure disagreed with those of the yield stress and the ultimate tensile strength. The relation between the mean pressure and the yield stress was described by the equation: σy=(P/3)(0.0017)n, where n is the strain hardening coefficient.
著者
小林 政治郎 山城 貞男 植村 幸生
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.13, no.125, pp.110-116, 1964-02-15 (Released:2009-06-03)
参考文献数
5

In this paper, the relations between Charpy impact strength (Absorbed energy/area under notch) and shape of V-notched test bar of unplasticized P.V.C. are described. The results obtained are summarized as follows:(1) Charpy impact strengths are not varied by the deviation of the width, the thickness and the notch angle of test bar in the range of experiment.(2) But they are varied by the deviation of the notch depth and the notch radius.(3) The quantitative values of error of impact strength which are introduced by these deviations are shown on Table I.
著者
清木 隆文
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.66, no.11, pp.793-798, 2017
被引用文献数
5
著者
下羽 悠一 石川 徹朗 大谷 眞一 秋田 貢一
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.55, no.12, pp.1139-1145, 2006 (Released:2006-12-20)
参考文献数
8
被引用文献数
3 4

The X-ray stress measurement based on sin2ψ method has been widely adopted. This technique is not entirely efficient, because it is necessary to measure each diffraction profile one after other at five and more incident X-ray angles. On the other hand, stress measurement based on cosα method was proposed using X-ray film as detector. In this method, the stresses are determined from Debye-ring obtained at a single X-ray incident angle with high efficiency. However, it has the problem in this accuracy on stress determination. In this study, a new stress analyzer with sixteen position sensitive proportional counters (PSPC) radially arranged for incidence X-ray was developed. We examined to determine the plane stress components by multi-regression analysis using sixteen diffraction angles on a Debye-ring. As a result, stress components of σx and τxy were measured with sufficient accuracy. However, a stress of σy had large dispersion, because of low strain sensitivity in the y direction. Moreover, it was clarified that σy had pseud-multicollinearity on multi-regression analysis. The accuracy of σy value itself could not be improved, though an analysis to eliminate an effect of pseud-multicollinearity was carried out. In this paper, we proposed the new method to determine the components using two Debye rings obtained by X-ray incidences in both x and y directions. We tried to measure the residual stress components in the butt welded joint using the method. As a result, it was confirmed that the stresses, σx and σy, were obtained in the sufficient accuracy, and that the shear stress, τxy, was arising near the bond in the welds.