材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
27 巻 , 303Appendix 号
選択された号の論文の15件中1~15を表示しています
  • 藤原 晴夫
    1978 年 27 巻 303Appendix 号 p. 1129-1140
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 青木 弘行, 上原 勝, 鈴木 邁
    1978 年 27 巻 303Appendix 号 p. 1141-1145
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Photo-oxidation of poly vinyl alcohol was studied under ultraviolet rays, and the amounts of carbonyl formation (aldehydic, acidic, ketonic and esteric type) were measured by IR method. Furthermore, the mechanism of photo-oxidation was estimated and the kinetics were investigated by the steady-state method.
    The results revealed that the rate of each carbonyl formation can be expressed by the equation, vc=o=B{1-exp(-At)} (A, B: const.). It can be seen from relationships between the changes of carbonyl formation ratio and the radiation time that the mechanism is content with the above equation, and thus the estimated mechanism of photo-oxidation is appropriate.
    Furthermore, the behavior of carbonyl formation was discussed on the basis of kinetic parameter (A), activation energy (Ea) and entropy of activation (ΔS). It is considered that the formations of aldehydic and acidic types contribute to the photo-oxidation of poly vinyl alcohol, while that of ketonic type depends on the decomposition of aldehydic type.
  • 三浦 精, 浜島 和雄
    1978 年 27 巻 303Appendix 号 p. 1146-1151
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    It has been known that an aluminum single crystal having <111> tensile orientation shows initial rapid hardening, its flow stress increases gradually until failure. However, many problems pertaining to the deformation mechanism of the <111> oriented single crystal remain unsolved.
    In the present study, to clarify the deformation mode of aluminum single crystals having multiple slip orientations, tensile tests were performed at various temperatures on <111> oriented single crystals.
    At room temperature, the <111> oriented single crystal deformed only by fine multiple slips and the flow stress increased with an increase of strain until failure. On the other hand, the coarse wavy slips composed of {111} and {100} slips occurred at high temperatures, such as 473K.
    In the single crystal having a tensile orientation deviated from <111> by a few degrees, the clustered slips were observed in addition to the fine multiple slips. It is concluded that the deformation mode and flow stress of single crystal are very sensitive to the tensile orientation in the vicinity of <111>.
  • 上村 啓二, 長岐 滋, 井上 達雄
    1978 年 27 巻 303Appendix 号 p. 1152-1157
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Coupling effects between temperature field and structural changes were considered in the analyses of structural changes and stresses due to quenching of steel from the viewpoint of continuum thermodynamics. A heat conduction equation with latent heat was derived by employing the mass fractions of structural components, and a finite element calculation was carried out to obtain the temperature and structural distributions.
    An elastic-plastic constitutive relation was presented considering the effect of dilatations due to phase changes as well as temperature variation, and stresses were analysed by the finite element method. The results calculated were compared with the experiments for a cylinder of 0.43%C carbon steel quenched in water.
  • 小寺沢 良一, 志茂 大治郎
    1978 年 27 巻 303Appendix 号 p. 1158-1164
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Stress corrosion cracking of a SUS304 stainless steel in boiling MgCl2 solution was studied fractographically with the aid of etch-pitting technique. An examination was also made on the applicability of linear fracture mechanics to SCC crack propagation. Fracture mode changed from transgranular to mixed intergranular-transgranular and again back to transgranular with an increase of stress intensity. The orientation of the transgranular fracture was predominantly {100} in fracture surface and <110> in propagating direction in the low stress region and changed to {110} surface and <110> direction in the high stress region. These fractures are likely to be caused by the complex effects of a number of mechanisms such as interaction of sessile dislocations or slip lines with chemical environment and decrease of surface energy in chemical environment. The linear fracture mechanics failed to valid in the high stress region where significant creep deformation was observed.
  • 大路 清嗣, 小倉 敬二, 久保 司郎, 片田 康行, 斎藤 英文
    1978 年 27 巻 303Appendix 号 p. 1165-1170
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The creep crack growth behavior of 1Cr-1 1/4Mo-1/4V steel was investigated at 565°C using center-notched plate specimens with proportional geometry in order to identify the most probable governing mechanical parameter of the phenomenon. It was found that even for this low ductile material the creep crack growth rate could successfully be correlated with modified J-integral J', regardless of the specimen size, while the stress intensity factor KI and the net section stress σnet gave poor correlation with the crack growth rate. This result was quite consistent with those obtained in previous papers using SUS 304 stainless steel which has a relatively high ductility. It was concluded that J' was the most probable mechanical parameter which governed the creep crack growth behavior.
  • 内田 猛, 岡部 永年, 矢野 利行, 森 忠夫
    1978 年 27 巻 303Appendix 号 p. 1171-1177
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to study the effect of notch on its impact fatigue strength of mild steels, low-cycle impact fatigue tests were carried out on the specimens of 0.2% carbon steel having various circumferential notches under repeated impact tensile loads. The experimental results are summarized as follows:
    (1) The impact low-cycle fatigue strength σ, in the case of notched specimens, is expressed by
    σNfm*Tn*=D*
    where Nf is the life of rupture, T is the loading time and m*, n* and D* are material constants.
    (2) The relations of m* and n* with the stress concentration factor α are given by
    m*=m0αa, n*=m0αb
    where m0, a and b are experimental constants.
    (3) The fatigue notch factor β is related to the stress concentration factor α by
    β=α-cexpm0a-1)lnNf
    where c is an experimental constant.
  • 小寺沢 良一, 森 時彦
    1978 年 27 巻 303Appendix 号 p. 1178-1184
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Effects of intermittent overloading on the crack propagation under creep conditions were studied with 304 stainless steels at 550 and 650°C. Intermittent loading remarkably reduced the life of specimens and the fracture took place at about the value of linear cumulative damage of 1/20∼1/40. The crack propagation rates were also remarkably accelerated to be about 20∼100 times as large as those of static creep cracks for a given value of net section stress. The fracture surface morphology under intermittent loading differed from that under a constant load of intergranular creep type, indicating extremely ductile transgranular fracture by glide plane decohesion. The remarkable reduction in life and the acceleration in propagation rate could be ascribed to the recovery of the material during the low stress period. Crack propagation rates under intermittent loading were correlated well with modified J-integral J and appeared to agree with the rates of creep cracks as well as fatigue cracks in the high stress range. Crack propagation rates at different temperatures also coincided well in the J diagram.
  • 藤井 太一, 前川 善一郎
    1978 年 27 巻 303Appendix 号 p. 1185-1190
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The fiber reinforced plastics (FRP) are now available for increased use in structural materials. FRP are, however, generally characterized by a considerable scatter in mechanical properties. Understanding the sources and nature of these variabilities is the key to better utilization of these composite materials. This paper deals with the two typical types of glass fiber reinforced composites (GRP) which are reinforced by plain-woven glass cloth and chopped strand glass mat. The main results obtained in this work are summarized as follows;
    (1) The mixture law of strength is applied to the modeled laminate which consists of three parts; the first part is the unidirectional layer aligned parallel to the load direction, the second is the layer which does not contribute to tensile strength and the third is the matrix layer. The mixture laws of the average and the variation of tensile strength are developed under an assumption that the fracture strengths of the first and third layers and the fiber volume content are random variables.
    (2) The average and the coefficient of variation of fracture strength in the first and third layers can be obtained by use of the bundle theory and the weakest link theory. The coefficient of variation of fiber volume content is given by the combination of the coefficient of variation of volume of reinforced material and that of thickness of laminate.
    (3) The calculated results of the average of fracture strength are found to agree well with the experimental whether each of the random variables are independent or not. But the coefficient of variation of strength is dependent on the correlation of each variables.
  • 斎藤 孝平, 安陪 勲
    1978 年 27 巻 303Appendix 号 p. 1191-1196
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to investigate quantitatively a complex effect of four variables, i.e., temperature t (-0.5∼+70°C), moisture content w (7∼29% WB), length of shreds L and stalk position p, on filling capacity (FC) of tobacco shreds, an experiment was carried out with two typical varieties in Japan, that is, Flue-cured V1 and Domestic V2 tobacco. Then the experimental data were analyzed by means of a statistical method.
    The important results obtained were as follows:
    (1) The complex effect of t, w, L, and p on (FC) can be represented by the following formula.
    (FC)=f(w)+f(w, t)+f(w, L)+f(p),
    where each function f on the right side of the formula is a quadratic function of variables shown in parentheses, for example w and t.
    (2) The degree of influence by variables on (FC) decreased in order of w>tp>L in the V1, and in order of w>tL>p in the V2.
    (3) In general, (FC) decreased as w or t increased, and (FC) showed a maximum value when L was a medium value.
    (4) Generally, (FC) of shreds cut from leaves on higher stalk positions was smaller than that of shreds cut from leaves on lower, and (FC) of V2 was greater than that of V1.
    (5) The variation of (FC) given in (1) to (4) corresponded well to the variation of elastic modulus of tobacco on the same condition.
  • 高津 学, 島川 一, 黒田 逸二
    1978 年 27 巻 303Appendix 号 p. 1197-1201
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    A new heat flux method is proposed for determining a thermal shock resistance parameter of ceramics. A ring shaped disc specimen is heated by the electro-conductive thin film glazed on its inner surface, and the time to fracture initiation is measured. At the same time, nondimensional thermal stresses occurring in the specimen under various heat flux conditions are theoretically calculated as a function of nondimensional time to give a set of reference curves. By combining the curves with the measured time, voltage and resistivity of electro-conductive film etc., the thermal shock resistance parameter, S/Eα, is easily determined. The experimental date obtained by this method are useful for designing ceramic materials used in firing kilns.
  • 日紫喜 基久, 堀 捷樹, 高野 博史, 川辺 秀昭, 上村 正雄
    1978 年 27 巻 303Appendix 号 p. 1202-1208
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to clarify the fatigue process of steel balls, an X-ray diffraction apparatus capable of carrying out various functions automatically has been constructed. The automatic functions include the X-ray measuring process, the process for changing and setting a steel ball on the specimen mount as well as renewing the measuring point, and the recording and computing process of the measured values. With this apparatus, the fundamental experiments for predicting the life of balls were carried out. The results obtained are summarized as follows;
    (1) With the present automatic X-ray diffraction apparatus, manual operations are only to set the first steel ball onto the specimen mount and to feed the punched tape of measured values to a computer.
    (2) This apparatus increases the measuring capacity and the efficiency of the calculation enormously. Furthermore, the personal errors, induced often during the X-ray diffraction profile analysis, can be eliminated completely.
    (3) By exchanging the machine parts of the ball supply system, this apparatus becomes applicable to steel balls of different diameters ranging between 6.35mm and 25.4mm.
    (4) There was a strong correlation between the variation of half-value breadth and the B10 life. The smaller the variation was, the longer the fatigue life became. From this fact, it was possible to estimate the fatigue strength of steel balls.
  • 本田 和男, 細川 智生, 皿井 孝明
    1978 年 27 巻 303Appendix 号 p. 1209-1215
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    In the present paper, the applicability of the counter method for stress measurement as one of the X-ray microbeam diffraction techniques is discussed. The stress can be measured at a local area of 330μ in diameter for Cr powder and 450μ for HT60 steel by using the crystal oscillation X-ray microbeam diffraction technique. The stress measured by this method agrees with the applied stress, and therefore, this method is suitable for both residual and applied stresses.
    As an example of the application of the method, internally notched plates were stretched and the stress distributions in the vicinity of notch tips were measured. The stress distributions obtained experimentally at the notch tips were similar to those calculated by the finite element method in the elastic regime. In the plastic regime, however, there was a slight discrepancy between them because of the influence of the yielding conditions of specimens.
    It is concluded that the counter method is a very effective mean for the studies of stress concentration problems and its application to the field of strength of materials is promissing.
  • 加藤 章
    1978 年 27 巻 303Appendix 号 p. 1216-1219
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The author has found that the recrystallization temperature of copper plating rises considerably when a very small quantity of gelatine is added to the plating solution. In this investigation, the copper electro-plating method has been tried at high temperatures by using the plating solution with 4mg/l gelatine. The result shows that this method can be applied for stress analysis up to about 250°C.
  • 小林 昭一
    1978 年 27 巻 303Appendix 号 p. 1220-1226
    発行日: 1978/12/15
    公開日: 2009/06/03
    ジャーナル フリー
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