材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
24 巻 , 266 号
選択された号の論文の11件中1~11を表示しています
  • 栖原 寿郎, 福田 重久
    1975 年 24 巻 266 号 p. 1003-1012
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 石川 皓一
    1975 年 24 巻 266 号 p. 1013-1017
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    In this paper, analysis has been made on the stresses, stress resultants and stress couples in a cylindrical reservoir, which is placed horizontally with partial supports at equidistance and subjected to soil pressure on its upper half surface, by utilizing the fundamental defferential equation introduced by Dr. K. Mizoguchi. The optimum form of supports are also obtained. Furthermore, precautions for using FRP as the material for a horizontal reservoir are described.
  • 金子 純久, 井内 建次郎
    1975 年 24 巻 266 号 p. 1018-1023
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    The grinding behavior in a ball mill has been studied mostly from the viewpoint of the effects of such main factors, as the velocity of revolution of the mill, the size of ball, and the packing ratio. However, there is no systematic investigation to clarify their interactions.
    In order to know the grinding behavior of silica sand in a ball mill, the interactions among the velocity of revolution of the mill, the size of ball, and the packing ratio are studied using the method of“the experimental designs”.
    The most effective condition for grinding silica sand with the particle size from 53 to 5μ is 72rpm, 31mm, and 30% for the velocity of revolution of the mill, the ball size, and the packing ratio, respectively. On the other hand, the most effective condition for the one with the particle size smaller than 5μ is 72rpm, 31mm and 20%. These results are used to discuss the grinding behavior in a ball mill.
  • 中沢 洋二, 寺沢 正男, 吉岡 靖夫, 浅見 克敏
    1975 年 24 巻 266 号 p. 1024-1030
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    It has been reported in the past that the tufftriding treatment improves the wear resistance of the iron and steel. For this reason, the tufftrided alloy tool steel is being widely used as the dies material for plastic working. However, its wear characteristics are hardly clarified.
    In the present study, the wear characteristics of the alloy tool steel (SKD 11) treated in various tufftriding time are investigated to find the most suitable tufftriding time.
    The following conclusions have been obtained.
    (1) The compound layer composed of two sub-layers is formed at the surface of specimen by the tufftriding treatment. The composition of the outside sub-layer is mainly the nitride of Fe (Fe3N, εFe3N-Fe2N) and that of the inside sub-layer is mainly the nitride of Cr (CrN, Cr3N).
    (2) The diffusion layer is formed under the compound layer, and both nitride and carbide are observed at the grain boundary in the diffusion layer.
    (3) The hardness value of the outside compound layer is lower than those of the inside compound and diffusion layers, and the outside compound layer comes off easily by the dry wearing at the room temperature.
    (4) The inside compound and diffusion layers contribute to the improvement of wear resistance, and the wear resistance is improved most when the specimen is tufftrided for about 12 hour.
  • 中島 孝慈, 三井 寿雄, 藤城 郁哉, 近藤 勉啓
    1975 年 24 巻 266 号 p. 1031-1037
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Tensile tests have been made on the bicrystal specimens of zinc under 1000kg/cm2 hydrostatic pressure. Four different types of bicrystal specimens have been prepared. Each had a longitudinal grain boundary parallel to the tensile axis, and was composed of the two component grains of <1010> and <1120> as the tensile axis, respectively.
    In the bicrystals the {1122} <1123> pyramidal slips accelerate the twin nucleation. The stress required to make this twin nucleated spread over the whole specimen is smaller than that required to initiate the twin nucleation and is much smaller when strain difference between the two twinned grains is larger. Once the twin had spread over the specimen, the deformation of the specimen proceeds in such mechanism as the pyramidal slip within the twins for the <1010> crystal, and the basal slip within the twins for the <1120> crystal. Thus, there is a large flow stress difference between the component crystals. The stress-strain curve of a bicrystal is well consistent with the mean curve of the component crystals, showing that the grain boundary had little effect on the stress-strain relationship. Microscopic observation of the deformed specimen shows that the compatibility requirements in the vicinity of the grain boundary should be satisfied by such factors as the basal and pyramidal slips in the matrix and twins, the kinks, the twins having small orientation factor and the secondary twins within the twins.
  • 井上 久爾男, 中川 憲治
    1975 年 24 巻 266 号 p. 1038-1043
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    A criterion for low-cycle fatigue has been developed on the supposition that the stress-strain hysteresis energy is a measure of fatigue damage. The total strain energy to cause fracture was calculated by means of the distributed element model which had been previously proposed by the authors. The result shows clearly that fatigue failure takes place when the strain energy accumulated in the most defective element having the maximum hysteresis loop reaches a certain value. On the basis of this fatigue criterion, the well-known plastic strain-cyclic life equation NΔεp2=C can be derived. In addition, a procedure has been developed for predicting the fatigue failure of a material subjected to complex stress-strain histories. The agreement between theory and the experiments is found to be satisfactory.
  • 飯田 一, 植村 益次
    1975 年 24 巻 266 号 p. 1044-1050
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    The fiberglass-reinforced composites fabricated by the filament-winding technique developed for convex pressure vessels have advantages especially in high specific strength. However, because of an analytical difficulty encountered with the arbitrary configuration and variation of anisotropic properties of shell structures, it is required to establish the analytical method of mechanical characteristics prior to its optimum design.
    In the present paper, by taking up a nearly spherical pressure vessel fabricated by the in-plane or planar winding technique, an analytical approach is presented to obtain the distributions of orthotropic elastic constants by use of the lamination theory, and then the stresses and strains in a revolutionary shell by the finite element method. As an example, a 480mm diameter rocket chamber developed for the fourth stage of Lambda rocket is analysed and a good agreement with the experimental values obtained in hydrostatic tests is shown to exist.
    Next, in view of the practical configuration of rocket motor chamber having junctions with adjacent stages, an analytical method of vessel structures with branching support is presented together with the constraint effects on strains in the vicinity of junction.
    Lastly, the practical loading cases encountered in test firing on the ground and in flight are compared with those under hydrostatic pressure. These three cases exhibit almost the same strain distributions, suggesting the applicability of hydrostatic proof test in the laboratory to check the mechanical characteristics.
  • 宮入 裕夫, 村松 篤良, 福田 秀昭
    1975 年 24 巻 266 号 p. 1051-1056
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Fiber reinforced plastics (FRP) are increasingly being used in many areas as large-size construction or connecting structures. Adhesive constructions are applied for architectural parts, various kinds of water tanks, sewage purifiers, etc. But the reasons and methods of using the adhesive construction and the estimations of the life of these constructions have not been clarified yet.
    This paper concerns with the durability of adhesive joints of FRP by means of an accelerating exposure testing machine, and investigates the fatigue properties of adhesive joints. All of the adhesive joint specimens were treated with popular construction of glass roving and mat structure, and were bonded with epoxy-polyamides adhesives. Accelerating exposure hours for the periods of 0, 1500, 2000, 3000 and 4000 hours (4000 hours are about 6 month) were chosen, and properties of joint structures were examined for the static and the fatigue strengths. The static tests investigated were the average shear strength of adhesive joints and the bending strength of glass fiber reinforced plastics (GFRP) materials exposed to the accelerating exposure testing machine. Fatigue tests were carried out under the stress constant amplitude with tension-shear loads, and the fatigue strength as well as the stress-strain hysteresis loop were examined. According to the test of accelerating exposure, damages of adhesive joints were not detected for 3000 hours in either the static or the fatigue strength, but, with the exposure time over 3000 hours, the static and the fatigue strengths abruptly went down. Therefore, the accelerating exposure time leading to damages is believed to exist between 3000 to 4000 hours.
    It is revealed that adhesive structures are strengthened in the beginning of accelerating exposure and break down abruptly with the lapse of exposure time. Accordingly, the design of FRP adhesive joints must be generally taken into consideration of the durable hours of these structures and the fatigue behavior of abrupt fracture under the tension-shear loads.
  • 松居 國夫, 清 隆行, 礎 良博, 岡田 信彦
    1975 年 24 巻 266 号 p. 1057-1064
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    The effect of deep freezing on the fracture behaviors of solid polymers has been investigated experimentally as a fundamental study of industrial cryogenic crushing operation. The apparatus used is shown in Fig. 1, which consists of an universal testing machine and a cryogenic thermostat with liquid nitrogen.
    As the temperature drops below the ductile-brittle fracture transition temperature Tc, the material becomes brittle and fracture takes place in the elastic range after a very small elastic deformation (Fig. 3).
    At higher temperatures T>Tc, the material stretches elastically until the yield stress is reached, whereupon the nominal stress decreases quite rapidly to a lower value with the appearance of a neck. The strain produced increases with temperature (Fig. 4).
    The homologous true breaking stress σBBc, the reciprocal homologous breaking strain εBcB, the homologous longitudinal elastic modulus E/Ec, the homologous crushing initiation index CII/CIIc, and the homologous crushing extension index CEI/CEIc increase with the reciprocal homologous absolute temperature Tc/T as given by Eqs. (5)∼(17) (Figs. 7∼16). The values of Tc, σBc, εBc, CIIc and CEIc at the ductile-brittle fracture transition temperature are the material-constants.
    The true tensile stress-strain curves and the tensile load-elongation curves for solid polymers at several temperature levels are shown in Figs. 9 and 10.
  • 宮本 博, 船見 国男
    1975 年 24 巻 266 号 p. 1065-1071
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    The main objectives of the present study are to make clear the mechanism of the cyclic work hardening of a single crystal and to simulate the stress-strain relation in the rapid hardening region as well as in the saturated hardening region. To achieve these purposes, the stress-strain relation of an Al single crystal was determined in a cyclic total strain controlling system. This paper deals and discusses how the Bauschinger effect depends on the crystal orientation factor and how the slip deformation differs between the two hardening regions.
    The results are summarized as follows.
    (1) Bauschinger strain γβ increased in proportion to pre-applied stress τF. That is, the Bauschinger effect decreased gradually with increasing the strain amplitude, and its rate depended on the crystal orientation, The Bauschinger effect decreased with increasing the number of cycles until its strain reached a constant value. In these ways, the Bauschinger effect is related to the condition of slip system motions.
    (2) For reversing of stress direction, the decrease of yield stress τB(=τF-|τR|) was formulated as
    τB=k·γFm
    where the Bauschinger exponent m depended on the crystal orientation and it was constant for each crystal until γR(0.01), or the plastic strain at τR=0, reached 0.01%. Then beyond this value, m increased with γR. With the increase of the number of cycles, the dependence of constant value m in these region on the crystal orientation became less.
    (3) In the rapid hardening region, the amount of the primary slip system became more pronounced as the cummulative strain increased. But in the saturated hardening region, the change in the amount of slip could not be observed even though the loading direction was reversed. In this region, the flip-flop motion of dislocations is considered to play a main role in primary slip system. On the secondary slip system, however, the slip motion was observed clearly. But during the tension to the compression process, the loci of slip motion were irreversible and were unsymmetrical due to the secondary slip in other slip systems.
  • 石川 浩
    1975 年 24 巻 266 号 p. 1072-1081
    発行日: 1975/11/15
    公開日: 2009/06/03
    ジャーナル フリー
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