著者

新井 義夫 上谷 長俊

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.15, no.152, pp.291-293, 1966-05-15

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The colored smoke trails from jet planes are generated by volatilizing colored smoke oils with hot exhaust gases from the jet engines. The colored smoke oil is a slurry, which is a mixture of selected dye with petroleum base oil. The colored smoke oil is a non-Newtonian fluid subject to the following power law. S=η' D^n where S is the shearing stress, D the rate of shear, η' the consistency index, and n the flow-behavior index. The following experimental equations were derived at low rates of shear. η'=η_0 exp (kC) (k>0) n=exp (-k'C) (k'>0) where η_0 is the viscosity of the base oil, C is the concentration of the dye, and k and k' are the constants to the kinds of dyes.

著者

三沢 俊平 末高 洽 下平 三郎

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.19, no.201, pp.537-542, 1970-06-15

被引用文献数

2

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The oxidation processes of Fe (II) hydroxo-complexes to α-, β-, γ-, andδ-FeOOH and Fe_3O_4 in aqueous solutions were investigated by processing measurements with infrared, far infrared, and Mossbauer spectra and X-ray diffraction of oxidation products. The effect of oxidation rate and addition of Cu^<2+> or PO_4^<3-> ion on the oxidation of Fe (II) hydroxo-complexes were also studied. It has been found that in the present experimental condition the process of oxidation depends on the pH-value of solution as follows : in basic solution (pH12.5〜13.5) Fe(OH)_2&roarr;α-FeOOH, in the slightly acidic solution (pH6〜6.5) β-Fe_2(OH)_3Cl&roarr;Green rust I&roarr;γ-FeOOH, and in neutral or slightly basic solution (pH7〜8) Fe(OH)_2&roarr;Fe_3O_4 and β-Fe_2(OH)_3Cl&roarr;Green rust I&roarr;Fe_3O_4. The infrared spectra of Fe(OH)_2 and Green rust I, an oxidation intermediate, have been obtained. The rapid oxidation of Fe(II) hydroxo-complexes in solutions with the addition of H_2O_2 results in the formation of δ-FeOOH. The oxyhydroxide has also been obtained by removing water from the Fe (II)-complexes, and leaving them in air to be oxidized. The broad absorption band at 450 cm^<-1> has been shifted for 480 cm^<-1> with the increase in size of δ-FeOOH crystallite formed by the oxidation of Fe(OH)_2 with H_2O_2. In the presence of Cu^<2+> or PO_4^<3-> ion, freshly precipitated Fe(II) hydroxo-complexes are oxidized into amorphous δ-FeOOH with air in solutions. This transformation is considered to have been caused by the catalytic effect Cu^<2+> or PO_4^<3-> ion in the oxidation of Fe(II)-complexes.

著者

谷本 敏夫 網島 貞男 石川 浩

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.28, no.304, pp.40-46, 1979-01-15

被引用文献数

2

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Fatigue tests have been conducted to investigate the fatigue properties of various types of laminated composites and some statistically meaningful inference was drawn from these results. The materials used in the experiment were 4 different kinds of FRP laminates, satin woven FRP, plain woven FRP, roving woven FRP and SMC laminated FRP. Sufficient approach based on the Weibull distribution was applied to the test data to evaluate the dispersion in the fatigue life of the materials. The dependences of fatigue life and its dispersion on the applied stress level, specimen size and fiber content in the specimen were discussed. The test results showed a wider experimental scatter particularly at the life range of 10^5 to 10^6 cycles than that observed on conventional metallic material. Thus it is emphasized that a larger reduction of design life is necessary for FRP to assure the same level of confidence and reliability as other materials.

著者

孫 峰 岩本 正治 自念 榮一 鈴木 惠

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.38, no.427, pp.360-366, 1989-04-15

被引用文献数

2

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The fracture mechanisms of plain woven fabric laminated composites were studied by load-displacement curves, AE behavior, and macro- and micro-observations in tensile tests. The results obtained are as follows: (1) The failure processes which are accumulative can be divided into three stages on the load-displacement curves of the composites. The stage I is elastic. In the stage II, the debonding in weft takes place. The stage III mainly corresponds to the matrix cracking and the separation between wefts and warps. They depend on the weave structure strongly but are related little with the ply number of laminates. (2) The boundaries of the stages I to II and II to III have some relations to the point where the AE event count rate can be detected first and the point where the rate increases rapidly, and thus the dominant failure mode can be well traced from the patterns of the AE event count rate and the AE energy curve.

著者

竹村 哲男 黒木 仁昭

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.13, no.128, pp.399-403, 1964-05-15

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Crystalline polymers show non-linear viscoelastic properties at very low excitations compared with amorphous polymers. It is very difficult to discuss the non-linear viscoelasticity generally, However, the degree of non-linearity has been defined at the temperature region where the dispersion due to crystal is important, as a result of considerations based on simple mechanical model and phenomenological method. The temperature dependency of this degree of non-linearity has been examined by making experiments of stress relaxation for high and low density polyethylenes and polyethylenet erephthalate. The result is that the degree of non-linearity is related to the dispersions closely, that is, the degree of non-linearity has larger values at the starting points of each dispersion. These facts suggest that the interaction between different dispersions will be the main factor for the non-linear viscoelastic mechanism.

著者

加藤 容三 広瀬 素尚 長谷川 典彦 片山 勲

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.33, no.373, pp.1264-1270, 1984-10-15

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Rotating bending fatigue tests were made on a quenched and tempered 0.45% carbon steel in the temperature range from room temperature to 450℃ at a machine speed of 3600 rpm. The fatigue strength σ_f at 4×10^4 to 3×10^7 cycles reached a maximum at about 350℃ due to cyclic strain aging in the same manner as the annealed material. For the quenched and tempered material the fatigue limit was clearly confirmed up to 200℃ but not observed at the peaking temperature of 350℃, while for the annealed material the fatigue limit had been confirmed even at 350℃. the fatigue strength of the quenched and tempered material was higher than that of the annealed material at every temperature, but the effect of cyclic strain aging on fatigue strength of the former was less than that of the latter. This suggests that this material shows different effect of cyclic strain aging at high temperatures when heat treated differently. The observation of fatigue crack propagation behavior revealed that the strain aging at 350℃ is more effective for the quenched and tempered material in preventing crack initiation rather than inhibiting crack propagation, contrary to the results of the annealed materials, which shows that strain aging is more effective in inhibiting crack propagation.

著者

吉原 浩 川村 拓司

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.56, no.4, pp.311-315, 2007 (Released:2007-04-20)

参考文献数

27

被引用文献数

6 7

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In this work, we examined the validity of four methods for measuring the mode I fracture toughness of wood; double cantilever beam (DCB), compact tension (CT), single edge notched tension (SENT), and single edge notched bending (SENB) tests, which have been frequently conducted. In the fracture tests, the crack length was variously changed, and the validity of each method was evaluated by the dependence of fracture toughness on the crack length. From the comparisons of fracture toughnesses obtained by the different four methods, the DCB test was more recommended than any other methods because the fracture toughness could be appropriately obtained in the wide range of crack length.

著者

川久保 昌平 平島 健一

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.46, no.9, pp.1011-1016, 1997-09-15 (Released:2009-06-03)

参考文献数

7

被引用文献数

3 3

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Elliptical ring subjected to arbitrary load has not been studied until now, although the solution for circular ring is easy to obtain. The analysis of elliptical ring enclosed by conforcal two elliptical boundaries is much complicated. In this paper, the general solutions of isotropic elliptical ring for stresses and displacements are obtained by the method of Laurent series expansion of complex stress functions and some numerical examples are shown. The accuracy and the rate of convergence of the present method are then discussed based on these solutions.

著者

荒木 健一 小澤 正邦

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.69, no.7, pp.532-537, 2020-07-15 (Released:2020-07-20)

参考文献数

36

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Effect of La2O3-Y2O3 additives on coating and thermal stability of alumina layer on FeCrAl-alloy substrate was investigated. The stable alumina catalytic coat layer is required and its processing parameters are important in practical technology to fabricate automotive honeycomb-type catalytic converters. The two-step modification in La2O3-Y2O3-modified Al2O3 induced better slurry regarding with surface charge as colloid dispersion and rheological properties with lower viscosity and low stress under moderate shear rate condition. Surface Y2O3 controls zeta potential to high pH region so that alkaline solution can be applied to metal and alloy substrates. The newly modified Al2O3 coat layer can react with alumina interlayer grown on FeCrAl alloy surface. In conclusion, the optimal coating stability was attained with present La2O3-Y2O3 co-doped Al2O3.

著者

日野谷 重晴 池田 昭夫 寺崎 富久長

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.27, no.292, pp.81-86, 1978

被引用文献数

1

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The fracture surfaces of ferritic-perlitic steel caused by hydrogen induced cracking (HIC) and sulfide stress cracking (SSC) under the wet H₂S environment were investigated by a scanning electron microscope. It was clarified that HIC and SSC were caused by hydrogen embrittlement. The cracks of HIC initiated around the nonmetallic inclusions (MnS) and they grew in a step-wise manner by connecting each other. On the other hand, the process of SSC took place as follows; the separated small cracks of HIC were connected by the cracks perpendicular to the stress axis. The fracture due to hydrogen embrittlement exhibited some characteristic fracture patterns, such as a river like pattern, flat pattern and so on. It was supposed that these fracture patterns were formed depending on the crystallographic orientation of grains. The striation type pattern was observed on the river like pattern as well as on the flat pattern. This striation type pattern seemed to correspond to the discontinuous propagation of hydrogen embrittlement cracking. In order to determine the sharp of the river like pattern, the stereo-matching technique was applied and it was found that this pattern could be classified into three types.

著者

山田 文二郎

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.16, no.169, pp.800-808, 1967

著者

岸本 秀弘 上野 明 河本 洋 浦 幸雄

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.38, no.424, pp.32-38, 1989

被引用文献数

1 7

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Tensile tests were carried out on sintered Si₃N₄ at room temperature under the ambient condition, and the influence of defects upon the fracture stress was discussed. As the surface of specimens was prepared carefully, fracture of 57 specimens out of 60 originated from the defects such as voids or inclusions which resulted from the sintering process. As a parameter to describe the size of the defect, &radic;<i>area</i> was used which is the square root of the area of a 3-dimensional defect projected to the direction of the maximum principal stress. The results obtained are as follows.<br>(1) &radic;<i>area</i> of defects which caused fracture nearly conforms to the first asymptotic distribution of the largest value and the fracture strength conforms to Weibull distribution.<br>(2) &radic;<i>area</i> is a good parameter to describe the size of the defect from the standpoint of fracture.<br>(3) Defects such as voids and inclusions act exactly as cracks of the same size.<br>(4) The fracture strength can be estimated by using the distribution of &radic;<i>area</i>, the fracture toughness and the mean grain size of Si₃N₄.

著者

山田 文二郎

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.16, no.169, pp.800-808, 1967-10-15 (Released:2009-06-03)

参考文献数

31

著者

安藤 桃子 杉村 和紀 上高原 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.70, no.7, pp.547-553, 2021-07-15 (Released:2021-07-20)

参考文献数

30

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Liquid crystallinity of (hydroxypropyl)cellulose (HPC) derivative in aqueous solution was examined to develop eco-friendly liquid-crystalline system. Bulky adamantoyl group (adamantyl ester) was introduced as a substituent on HPC, and the effects of the degree of adamantoyl substitution (DSAd), polymer concentration, and temperature on the chiroptical properties, especially coloration and turbidity, of the aqueous lyotropics were investigated by circular dichroism, CD, and ultraviolet–visible–near-infrared, UV–Vis–NIR, spectrophotometry. Adamantates of HPC (Ad- HPCs) with extremely low DSAd (< 0.1) were successfully synthesized by acylation of HPC with 1-adamantanecarbonyl chloride in tetrahydrofuran. Ad-HPCs of DSAd ≤ 0.08 were highly soluble in water, and the concentrated aqueous solutions formed a right-handed cholesteric liquid-crystalline phase to impart vivid reflective colorations. The cholesteric helical pitch P, comparable to the wavelength of maximal reflectance λmax, increased with increasing DSAd of Ad-HPC and with decreasing polymer concentration. Wide-angle X-ray diffractometry, WAXD, revealed that the increases of P were attributable to the decrease of the twist angle ϕ between adjacent thin nematic layers. The aqueous Ad-HPC lyotropics were phase-separated and became turbid at an elevated temperature of > ∼30°C. Such a lower critical solution temperature (LCST)-type phase separation behavior of the Ad-HPC/water system was also affected by the hydrophobic adamantoyl group; the observed cloud point Tc was shifted to lower temperature side with increase in DSAd, presumably due to the heightening of hydrophobic interactions between the solute Ad-HPCs in water.

著者

山田 直樹

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.67, no.10, pp.943-949, 2018-10-15 (Released:2018-10-20)

参考文献数

19

被引用文献数

2

著者

鎌田 浩毅

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.52, no.5, pp.444-451, 2003-05-15 (Released:2009-06-03)

参考文献数

41

被引用文献数

1 1

著者

井上 真澄 Khamhou Saphouvong 児島 孝之

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.56, no.12, pp.1183-1188, 2007

被引用文献数

1

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Recently, the concern with acrylic resin as a new repair material has been growing. The acrylic resin is characterized by high quality, low viscosity, highly elongation percentage and so on. Several studies have been made on the crack repair by using acrylic resin, but little is known about the effect of acrylic resin as a crack repair material for concrete.<br>The purpose of this study is to examine the applicability of acrylic resin for using as a crack repair material for the concrete structures. The fundamental mechanical properties of acrylic resin by using super lightweight powder were examined. And the repair effects of acrylic resin as crack repair material were examined by the flexural loading test of the concrete member repaired by crack injection technique. As a result, acrylic resin could adjust the viscosity by using super lightweight powder, and the elongation percentage of acrylic resin was superior to epoxy resin. The crack repair effects of acrylic resin were equivalent to the epoxy resin under drying condition of the crack surface of concrete member.

著者

菊池 将一

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.64, no.6, pp.501-502, 2015

著者

米澤 政昭 奥田 昇也 朴 永太

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.12, pp.1204-1209, 1998-12-15 (Released:2009-06-03)

参考文献数

12

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This paper describes a new numerical integration method for evaluating structural failure probability. The proposed method utilizes the centerline directional vectors, which are related to the specified numbers of finite element meshes divided on the surface of the unit hypersphere. The failure probability is evaluated numerically by using the values of hyperareas of the finite element meshes and conditional failure probabilities on the centerline directions of the meshes. To save computational efforts, the calculation of the conditional failure probabilities is restricted in the effective directional regions, where all the distances from the origin to limit state surfaces are short enough and within the limit of the effective distance range. The effective distance range is determined in the preliminary search procedure to get the information about the limit state surfaces situation.Numerical examples are presented to illustrate the validity of the proposed method to evaluate the structural failure probabilities.

著者

河村 進 大畑 敬 村田 功二

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.58, no.4, pp.280-285, 2009

被引用文献数

1 1

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It is known that the shear performance of plywood depends on the grain direction of veneer sheets, and if veneer sheets are oriented 45 degree against the lateral sides, it indicates highest shear performance. Authors produced experimentally the diagonal plywood, which were laminated parallelogram veneers oriented diagonally against the lateral sides. The in-plane shear performance of the bearing wall, which joined diagonal plywood to the frame with the nail spaced 50mm to 150mm apart, was evaluated by racking test. When the nail space was shortened, load at yield point increased, but maximum load of diagonal plywood was almost equal to standard plywood. The comparable result was also obtained from the lateral nail resistance test.<br>In conjunction with this, shear strain distribution of panel was measured by digital image correlation (DIC), and approximate shear modulus of panel could be calculated from load-strain curve. Shear strain of diagonal plywood was lower than that of standard plywood. The bearing wall using diagonal plywood indicated large initial stiffness. As a result, it was concluded that bearing wall using diagonal plywood indicates higher reference shear strength. In order to increase the shear strength that is added to diagonal plywood, it is effective if the interval of nail is to some extent shorter than 150mm, which is the specification of wall index 2.5 of bearing wall using standard plywood. Shear modulus of full-sized diagonal plywood was about 4 times as much as that of standard plywood.