Journal of the Society of Materials Science, Japan
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
Volume 23 , Issue 254
Showing 1-17 articles out of 17 articles from the selected issue
  • Shigeru KISHIMA
    1974 Volume 23 Issue 254 Pages 890-901
    Published: November 15, 1974
    Released: June 03, 2009
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  • Satoshi OKUDA
    1974 Volume 23 Issue 254 Pages 902-911
    Published: November 15, 1974
    Released: June 03, 2009
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  • Takashi SUZUKI
    1974 Volume 23 Issue 254 Pages 912-923
    Published: November 15, 1974
    Released: June 03, 2009
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  • Masamichi KOWAKA
    1974 Volume 23 Issue 254 Pages 924-935
    Published: November 15, 1974
    Released: June 03, 2009
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    The corrosion behavior of ferritic stainless steels is reviewed. The intergranular corrosion behavior of commercial purity ferritic stainless steels had been believed to be quite different from that of austenitic stainless steels. The heat-treatment that would make ferritic alloys susceptible makes the susceptibility of austenitic alloys to become minimum. Recently, however, it has been shown that the behaviors of both ferritic and austenitic stainless steels can be explained by the chromium depletion theory. The difference in their behavior described above is considered to be due to the very low solubility and rapid diffusion rate of carbon and nitrogen in the ferrite phase compared with the austenite phase. The effects of heat-treatment and alloy composition on the susceptibility to intergranular corrosion are also outlined.
    The increase in chromium and/or molybdenum contents of Fe-Cr alloys markedly increases the resistance to pitting and crevice corrosion in chloride environments. Ferritic stainless steels are known to be highly resistant to stress corrosion cracking, but when the alloys contain nickel or copper, they become susceptible to stress corrosion cracking. The susceptibility of ferritic stainless steels to hydrogen embrittlement is also discussed briefly.
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  • Koji YAMAKAWA
    1974 Volume 23 Issue 254 Pages 936-945
    Published: November 15, 1974
    Released: June 03, 2009
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    Hydrogen embrittlement and corrosion fatigue were reviewed and discussed. The necessity of the determination of hydrogen solubility in steel was emphasized in order to discuss the hydrogen embrittlement phenomenon. As for the corrosion fatigue, many typical examples were presented to illustrate that many parameters affect this complicated phenomenon. Most of the discussions were focused on the problems of engineering importance. It was pointed out that the measurement of corrosion current is useful as the criterion for evaluating the strength of corrosion fatigue.
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  • 1974 Volume 23 Issue 254 Pages 946-953
    Published: November 15, 1974
    Released: June 03, 2009
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  • Tsuneo HIRAI, Haruo YOSHIDA
    1974 Volume 23 Issue 254 Pages 954-959
    Published: November 15, 1974
    Released: June 03, 2009
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  • Sadao AMIJIMA, Toshio TANIMOTO
    1974 Volume 23 Issue 254 Pages 960-965
    Published: November 15, 1974
    Released: June 03, 2009
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    An investigation was conducted on the static and fatigue properties of carbon fiber reinforced plastics, especially on the effects of environmental test temperature and the volume content of carbon fiber in the specimen.
    The material used for preparation of the unidirectional laminates was P301 prepreg sheet supplied by Toray Industries Inc.. This is a high strength prepreg tape made with epoxy resin and carbon fibers.
    The tension test, bending test and interlaminar-shear test by short-beam method were conducted as the static tests, while the repeated bending test and rotating bending test were carried out as the fatigue tests.
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  • Yoshifumi SUEZAWA
    1974 Volume 23 Issue 254 Pages 966-972
    Published: November 15, 1974
    Released: June 03, 2009
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    In order to make clear the mechanical properties of FRP bicycles, a study was carried out and some of the experimental data connected with the trial manufacture of FRP bicycles are presented.
    This report consists of two sections, one dealing with the investigation on a Bowden FRP bicycle, and the other with the trial manufacturing study of our FRP bicycle. The Bowden bicycle did not show any excellent mechanical strength nor smooth handling stability. At the beginning of the trial manufacturing of our FRP bicycle, the study on the proper selection of basic glass material was made bused on the results of the mechanical strength tests (tensile and bending tests) on various materials. The combination of SLS-213 (satin) 2 ply and CM 305 (chop strand mat) 1 ply was found to be the best material for FRP bicycle. The resin used in this experiment was an unsaturated Polyester resin. In order to reduce the assembly cost, the following points were taken into consideration during the design of frame.
    (1) The frame body, rear mudgard and chain case were integrated into one unit.
    (2) The left and the right half FRP shells were joined at the center line of the frame by Epoxy resin.
    (3) The principal parts of FRP shell frame were reinforced with mild steel plates.
    (4) At the head and hanger portions of the frame, steel pipes were attached to the FRP shell so as to secure the smooth rotation of ball bearings.
    As regards the strength of the trial manufactured bicycle, the statical load test, the bending test and the vibration test were conducted. It was apparent that the mechanical strength of the present FRP bicycle was superior in comparison with an ordinary steel-made bicycle. Also there was no defects observed on the 1040km road running test.
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  • Yuitiro MASUDA, Juniti YAMASAKI
    1974 Volume 23 Issue 254 Pages 973-979
    Published: November 15, 1974
    Released: June 03, 2009
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    Many of the FRP plates used frequently among various types of composite materials are orthotropic. While the shear modulus G12 in the in-plane shear deformation of an orthotropic plate can be measured by the plate-twisting test method, it is not easy to measure shear moduli G13, G23 in the out-of-plane shear deformation.
    This report gives an account on the method to measure these shear moduli by means of torsional testing of an orthotropic rectangular bar.
    The relation between the torque M and the angle of rotation per unit length θ in the case when a rectangular bar is cut out along one principal axis of the plane, for instance along the l-axis direction, and subjected to the torsional testing, is as follows:
    M=G12θh3b/3F, F=1-192/π5h/βbtanhπ/2βb/h
    where h is the thickness of cross section, b the breadth of cross section and β2 the value of G13/G12.
    The values of G12, G13 can be calculated from the forgoing equation by carrying out the torsional testing on two bars of b/h≈1 and b/h=5∼10.
    G13(G23) is the value related to the interlaminar shear characteristics of a composite material, and the measurement of this G13 is important in studying the physical properties of composite materials, for instance, in investigating the mechanism of decrease in stiffness due to fatigue.
    The present report also refers to the method of torsional testing using Instron type testing machine and the results of the measurement of G on FRP plates.
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  • Haruo YOSHIDA
    1974 Volume 23 Issue 254 Pages 980-986
    Published: November 15, 1974
    Released: June 03, 2009
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    Fiber reinforced plastics are often used as structural materials at the stress level higher than their elastic limit or proportional limit, since these limits are lower compared with the ultimate strength of the materials. In such case, the stress-strain relation is not linear.
    For the purpose of obtaining the non-linear stress-strain relationship mathematically, the author set up a mechanical model which could reasonably express the visco-plasto-elastic properties of FRP.
    A simulated fatigue test on this model subjected to sinusoidally repeated stresses was carried out, by means of an electronic computer. By the comparison of the calculated results with the data obtained by the experimental fatigue tests on fiberglass mat reinforced polyester resin laminates, the parameters of the model could be determined, and the specified differential equation for the material, which can be used to express the stress-strain diagram and the rigidity transient caused by fatigue failures, was determined in the concrete.
    Thus the mathematical analysis of the mechanical behavior of visco-plasto-elastic materials such as FRP is now possible.
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  • Mitsuo TAKEHANA, Isao KIMPARA, Akira HAMAMOTO
    1974 Volume 23 Issue 254 Pages 987-992
    Published: November 15, 1974
    Released: June 03, 2009
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    Fiber glass reinforced plastics (FRP) has now become to be used as structural materials in many fields. The mechanical properties of FRP vary widely depending upon the configuration and volume content of glass reinforcement. Glass fabrics woven by roving and mats of chopped strand are often used in FRP for large-sized structures such as ships and boats. This type of FRP contains a medium amount of fiber among various kinds of FRP. The mechanical properties of such FRP show often time-dependence even at near room temperature due to viscoelasticity of the matrix.
    The objective of this study is to clarify the rule of mixture governing the viscoelastic behavior of composite materials such as FRP from macroscopic and microscopic viewpoints. In this paper, as the first report of this study, the relaxation moduli of two types of FRP, consisting of unsaturated polyester reinforced with woven rovings and chopped strand mats have been analyzed by means of a simplified model, in which the effect of the constitution of reinforcement and the time-dependent Young's modulus of matrix was taken into consideration, and compared with the experimental results. At first, the simplified elastic model including the effect of the configuration of reinforcement was devised to express Young's modulus of FRP with woven roving or chopped strand mat in terms of elastic moduli of the constituents. The accuracy of the model was confirmed by tensile tests of FRP with various glass contents. Then the viscoelastic behavior of unsaturated polyester resin at room temperature was examined, and the time-dependence of Young's modulus of matrix was obtained based on a four-element mechanical model. The relaxation modulus of FRP was then calculated by substituting the time-dependent Young's modulus of the matrix into the above model. The calculations have been shown to agree fairly well with the results obtained by stress relaxation testing of FRP at room temperature.
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  • Sadao AMIJIMA, Tsuneyuki ADACHI
    1974 Volume 23 Issue 254 Pages 993-999
    Published: November 15, 1974
    Released: June 03, 2009
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    Generally, a solid material has the linear stress-strain response within a certain stress level, beyond which up to the failure the stress-strain relation becomes non-linear.
    This paper presents a method of predicting the non-linear stress-strain response up to the tensile failure for an orthotropic lamina and a laminated composite consisting of orthotropic lamina. The present technique is restricted to the prediction of the stress-strain curve for plane anisotropic laminates with midplane symmetry subjected to uniaxial membrane load. The comparison between the analytical predictions and the experimental results shows that the predicted non-linear stress-strain responses approximately coincide with the experimental results.
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  • Tsuneo HIRAI, Toyoki TANAKA, Tsutao KATAYAMA, Teruo KIMURA
    1974 Volume 23 Issue 254 Pages 1000-1006
    Published: November 15, 1974
    Released: June 03, 2009
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    Recent development of carbon fiber and its hybrid composites with metals has required the analysis of the deflection characteristics of the beams made of these materials under bending load of short duration.
    It was found that the deflection of the specimen of CFRP-Al composite under four-point bending could be satisfactorily predicted by the finite element method assuming anisotropic and isotropic characteristics for carbon fiber and aluminum, respectively. The volume fraction of the reinforcement and the order of laminations have a marked influence on the relative stiffness. An optimum design for each of various applications may be achieved by considering such influence.
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  • Tsuneo HIRAI, Shoichi FUJIWARA, Kyozo TAKIMOTO, Kazuo OZAWA
    1974 Volume 23 Issue 254 Pages 1007-1013
    Published: November 15, 1974
    Released: June 03, 2009
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    In recent years the applicable field of glass fiber reinforced plastics (FRP or GRP) has remarkably expanded. This paper is presented to give direction in the proper selection of reinforcement and FRP combinations in order to satisfy the functional requirements and assemblies for repeated impact flexural load using falling weight.
    The fatigue strength was investigated macroscopically by measuring the logarithmic decrement and strain under repeated impact load. The rapidly decrease in elastic modulus in fatigue has been observed. Microscopically, the cracks, which appear to be caused by stress wave produced by impact load, were found to occur in the laminated resin layers over considerably wide range along the longitudinal direction of beam and progress across the layer into the fiber bundle of reinforcement. The strength under repeated impact loading was representable in terms of the number of cycles to failure under constant impact energy.
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  • Sadao AMIJIMA, Toshio TANIMOTO, Yoshio KURAMOTO
    1974 Volume 23 Issue 254 Pages 1014-1021
    Published: November 15, 1974
    Released: June 03, 2009
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    An investigation was conducted on the fatigue properties of glass fiber-reinforced plastics, especially on the effects of fiber orientation and volume content of glass fiber in the specimen.
    The material used was a FRP laminate consisting of polyester resin as the matrix and plain woven glass cloth as the reinforcement.
    Sufficient data have been obtained to produce the master diagram for this material. An empirical equation is proposed to predict the fatigue limit of off-axis specimens as a function of mean stress.
    The applicability of static failure criterion to the off-axis FRP materials subjected to cyclic load is examined by employing a modification factor.
    In addition, the potential advantage of prestressing the reinforcement prior to its bonding to the matrix in FRP materials is investigated.
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  • T. Tokuoka
    1974 Volume 23 Issue 254 Pages 1022-1025
    Published: November 15, 1974
    Released: June 03, 2009
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