日本機械学会論文集 A編
Online ISSN : 1884-8338
Print ISSN : 0387-5008
54 巻, 507 号
選択された号の論文の20件中1~20を表示しています
  • 袁 世峰, 麻生 和夫, 谷 順二
    1988 年 54 巻 507 号 p. 1943-1948
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    On the basis of linear beam theory, the static behavior of a pipe string designed for mining manganese nodules is formulated as a singularly perturbed boundary-value problem. This problem is analyzed by the method of matched asymptotic expansions and Galerkin's method. Static pipe deflections and bending moments are evaluated for the practical range of towing speeds of the ship. The pipe deflections obtained by Galerkin's method agree well with those by the method of matched asymptotic expansions. However, it is found that Galerkin's method with the beam function is not effective in evaluating bending moments of the pipe string.
  • 宮川 松男, 矢田 敏夫, 古口 日出男, 本沢 豊茂
    1988 年 54 巻 507 号 p. 1949-1955
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Development of reliable bonding techniques for ceramics and metals is considered very important for more useful applications of ceramics. Generally, however, it is a serious problem that ceramics have a high thermal stress concentration at the bonded interface, caused by different thermal properties of both materials. The authors have been investigating various methods for effectively decreasing the stress concentration. In this paper, they present a fundamental consideration on the thermal stress distribution characteristics to the interface of dissimilar material joint, by using thermoelastic-plastic finite element analysis. Through this analysis, it is found that the high thermal stress is induced only in very narrow region, and that the value of the high stress is approximately estimated by a simplified theoretical analysis.
  • 立花 俊一, 川地 俊一, 山田 邦博, 国尾 武
    1988 年 54 巻 507 号 p. 1956-1961
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    The relationship between the endurance limit and ferrite grain size was investigated in a wide range of ferrite grain sizes using smooth specimens of low carbon steel, medium carbon steel and low alloy steel under rotating bending. It was found that the endurance limit of ferritic pearlitic steel clearly shows the Hall-Petch type relationship when the metallurgical parameters, such as chemical compositions and microstructural morphologies, are the same. The endurance limit can be determined by the additive effect of the strength level of matrix ferrite and the grain refinement. The effect of grain refinement on the endurance limit was constant irrespective of the strength level of matrix microstructure.
  • 野口 徹
    1988 年 54 巻 507 号 p. 1962-1966
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Zero-to-tension fatigue tests were performed on flat and notched bars of three gray cast irons, and the notch sensitivity was discussed based on the stress distribution obtained by considering the nonlinear behavior of the material. In flake graphite iron, the notch factor for notches with form factors 1.6 and 2.8 was 1.1-1.2 near the fatigue limit, this is higher than the notch sensitivity in static strength, but lower than that at fatigue in ductile iron. Calculated stress under the notch exceeded the fatigue strength of flat specimen down to 0.6-1.4 mm depth depending on the number of cycles to failure, matrix ductility, and notch radii. The minimum depth was 1/2-1/3 of this value in static rupture, equal to 1-2 graphite eutectic cell diameters, and was considered a minimum stress depth for crack formation.
  • 石原 外美, 宮尾 嘉寿, 前川 一郎
    1988 年 54 巻 507 号 p. 1967-1973
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Rotary bending fatigue tests were performed on annealed and shot-peened specimens in laboratory air and in salt water. During the fatigue process of a shot-peened specimen in air, many cracks are initiated but each crack growth is suppressed by work-hardening and compressive residual stresses produced by shot-peening treatment ; hence, under this condition, crack coalescence is the only possible way for crack growth to occur, and is thus one of the most important factors to decide fatigue life. On the other hand, during the fatigue process of a shot-peened specimen in salt water, especially at low stress amplitude, suppressive effects of shot-peening treatment on crack growth are lost under a strong corrosive environment. In this case, many cracks can grow to a considerable long crack size, and they distribute not only in a circumferential direction but also in a longitudinal direction of the specimen. Consequently, stress relaxation will occur in the cracked part of the specimen and crack growth rate will be reduced. This stress relaxation effect on crack growth exceeds the crack coalescence effects in a corrosion fatigue process at low stress amplitude.
  • 倉茂 道夫 /, Rodney J. CLIFTON
    1988 年 54 巻 507 号 p. 1974-1979
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    For the problem of a pressurized plane crack in an infinite fluid-filled porous elastic solid, a pair of integral equations is obtained, which relates normal traction and pressure on the crack faces to crack openings and fluid mass supply rate per unit fracture area, by making use of the fundamental solution to an infinitesimal segment of a dislcation line.
  • 倉茂 道夫
    1988 年 54 巻 507 号 p. 1980-1986
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    By extending Cleary's version of the mechanics of fluid-filled porous elastic solids, we obtain basic equations of thermoelasticity for such solids. For the case of an irrotational displacement field, this field is uncoupled with coupled fields of temperature and pore fluid pressure. Field equations are examined by their application to a simple one-dimensional model problem, and the following are shown : (1) for granites, we can neglect the term which presents heat transfer by pore fluid flow ; (2 ) for sandstones, we can solve the temperature epuation by making it uncoupled with the pressure field which can be regarded as a steady state for all time ; (3) for solids of very high fluid-mass diffusivity such as Berea sandstone, we can neglect a heat conduction term in the field equations.
  • 須見 尚文, 野田 直剛
    1988 年 54 巻 507 号 p. 1987-1992
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    A solution is given for three-dimensional transient thermal stresses due to a local source of heat that moves back and forth with a constant angular velocity over the surface of an infinite elastic slab. The temperature distribution is obtained by means of the Fourier and Laplace transforms, and the associated thermal stresses are obtained by making use of the thermoelastic displacement function and the Galerkin function. Graphical representations of the solution in i\dimensionless terms are included in this paper.
  • 菅野 良弘, 木元 順一
    1988 年 54 巻 507 号 p. 1993-1999
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    An analytical solution is presented for a stochastic thermal stress problem in a nonhomogeneous flat plate. The flat plate has arbitrary variations in mechanical properties and is subjected to surface temperatures expressed by stochastic functions with respect to time. The analysis leads to exact expressions of the response autocorrelation functions and the response power spectral densities for temperature and stress. The deterministic thermal stress expression in a nonhomogeneous flat plate which has been reported by one of the present authors, is used in this analysis. Numerical calculations are carried out for the case in which the surface temperature is assumed to be a white noise.
  • 畑 俊明
    1988 年 54 巻 507 号 p. 2000-2006
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    When a hollow sphere is subjected suddenly to a uniform temperature rise over its cross section, stress waves occur at the internal and external surfaces the moment thermal impact is applied. The stress wave at the internal surface proceeds radially outward, while the one at the external surface proceeds radially inward. During instantaneous heating, the interfering effects of these waves can cause a very high dynamic stress for both tension and compression in the sphere. This paper analyses the effects of these waves precisely using the ray theory. The numerical results indicate the variations in the dynamic stresses in a sphere with time.
  • 辻 知章, 野田 直剛, 渋谷 寿一, 小泉 堯
    1988 年 54 巻 507 号 p. 2007-2013
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Torsion problems for a stepped-bar composed of two semi-infinite bars bonded to each other by an elastic adhesive layer are investigated. When the behavior of the adhesive layer is handled in elasticity, a stress singularity occurrs at the corner of the bare. Therefore, the stress analysis proceeds considering this stress singularity by making use of the series expansion technique, and the problems are reduced to an infinite set of systems of linear equations. Moreover, the stress fields in the neighborhood of the corner are shown by singular terms with only one parameter which is similar to the stress intensity factor. The stress distribution and the values of this parameter are shown for various values of the mechanical properties of the bars and the adhesive layer. In addition, the results are compared with the ones for problems in which the behavior of the adhesive layer is approximated by that of the shear springs.
  • 大槻 敦巳
    1988 年 54 巻 507 号 p. 2014-2018
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    In a bending test of engineering materials such as spring steels and plastics, a fairly large deflection is observed without exceeding the elastic limit of materials. It is of great technological interest to know the large deflection behavior for various loading styles. This report deals with the problem of nonlinear large deflections of a thin elastic, three-point simply supported beam with a nonsymmetrical vertical load and gives analytical solutions for typical flexible quantities such as the deflection, arc length, curvature and bending stress. Moreover a large flexural bending test is carried out in order to confirm the applicability and reliability of the proposed theory. The experimental results are in good agreement with ones obtained by the analytical theory. Therefore the nonlinear large deflection theory presented here can be put into practical use.
  • 竹園 茂男, 右田 康治
    1988 年 54 巻 507 号 p. 2019-2027
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    The paper describes an analytical formulation and a numerical solution of the creep problems of anisotropic multi-layered moderately thick shells of revolution whit application to a cylindrical shell. The analytical formulation is developed by extending the Reissner-Naghdi theory for elastic shells with consideration given to the effect of shear deformation. For the constitutive relation, Hooke's law for orthotropic materials is used in the elastic deformation, and equations based on the orthotropic creep theory derived from the orthotropic plastic theory by Hill are employed in the creep range. The creep strains are related to the stresses by McVetty's equation having the thermal effect multiplier by Arrhenius. The basic differential equations derived are numerically solved by a finite difference method. As a numerical example, the creep of a two-layerd, anisotropic cylindrical shell composed of mild steel and stainless steel subjected to uniform internal pressure is analyzed. Numerical computations have been carried out for four cases of the combinations of the directions of the anisotropic principal axis. It is found from the computations that the internal force distributions and the deformation are significantly varied depending on the combinations of the directions in layers.
  • 北澤 敏行
    1988 年 54 巻 507 号 p. 2028-2033
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper is concerned with a compression experiment in the case of different eccentricities at upper and lower ends on carbon steel thin-walled square pipes with various a/c rstios in the skort column range, supported with sphevical seats. An expirical formula for calculating eccentric compressive buckling stress "σceo" of the carbon steel thin-walled square pipes is presented as follows : σceocr=1/{1+2.8(eo/c)}, eo=√((e12-e22)/2) where σcr=axial compressive buckling stress, e1=upper eccentricity e2=lower eccentricity, c=mean distance between walls, a=length. The measurement reveals that the results calculated by this equation are in good agreement with those obtained experimentally for the short column range.
  • 雑賀 雅之, 清水 真佐男
    1988 年 54 巻 507 号 p. 2034-2038
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Fracture behavior of the steels with a ferrite-martensite and a ferrite-pearlite microstructure has been investigated with special attention to the relationship among ductility, fracture mechanisms and microstructures. A well known dependency of fracture ductility (εf) on the volume fraction of second phase (Vfs) found originally by Edelson was confirmed for each microstructure, but a marked difference in such a dependency was observed between those microstructures when the different fracture mechanisms are involved, indicating that a single relationship between εf and Vfs appears only for the two phase microstructure in which the fracture mechanism is identical. A new concept of the fracture ductility surface has been proposed to explain the microstructural effects in fracture ductility of the two phase alloys. Using this concept, and interpretation was given to the scatter of the fracture ductility of present materials and to the dependency of εf on the morphology of microstructure and on the hardness ratio between the constituents in two phase microstructure.
  • 瀧本 昭夫, 小田 直樹, 藤井 敏男
    1988 年 54 巻 507 号 p. 2039-2046
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    We have reported that fracture surface marks in brittle plastic sheet specimens having short (≤ 5mm) and long (≥ 40mm) central primary cracks are well expressed by equations under the fracture conditions of a constant load (or stress) and a constant deflection (or strain), respectively. Here, we discuss the velocity and the marks in the specimens having an intermediate-length central crack. The crack velocity is measured and expressed by an equation where the velocity is presumed to be composed of both constant stress and strain components. In this case, a fracture starts with a constant stress condition which changes gradually to a constant strain condition as the crack propagates, and we call this a fracture in a mixed condition. This velocity expression, combined with the existing relation between crack velocity and a dynamic stress-intensity factor, gives the variations of the dynamic stress-intensity factor and a dynamic strain energy release rate both of which excellently predict the experimental variations of the fracture surface marks in those specimens such as the number of marks, the relative interference appearing distance (e/Co2) and the relative critical distance (d/Co2).
  • 高坪 純治, 岸 輝雄
    1988 年 54 巻 507 号 p. 2047-2055
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    Using a six-channel recording system, acoustic emission signals during fracture toughness testings of ASTM A533B steel were detected, located and characterized. Two samples of A533B steel with different sulfur content (medium sulfur sample : 0.013% S, low sulfur sample : 0.003% S) were prepared, and the AE characteristics were compared. In the medium sulfur sample whose fracture toughness is less than that of the low sulfur sample, two types of AE signals were detected. One was a signal due to microcracking at the MnS inclusion, and the other was a signal due to coalescence of the voids. In the low sulfur sample, only the former type of AE signals were detected, which means that, in this experiment, coalescence of the voids did not occur in the low sulfer sample because of its high fracture toughness. The results of the source wave analysis showed that microcracking at the inclusions was due to mode I type tension cracks with sizes of 10∼30 μm, and the coalescence of the voids was due to tension shear mixed cracks with sizes of 60∼100 μm.
  • 池田 清彦, 井垣 久
    1988 年 54 巻 507 号 p. 2056-2060
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    The mixed-mode fracture criterion of modes I and II of Soda-Lime Glass was investigated using inclined indentation surface flaws in four-point bending. In order to examine the effect of mode II on the extension of cracks, the specimens with an inclined surface flaw oriented at an angle of 45° with respect to the outer fiber tensile stress direction were fractures under hydrostatic pressure up to about 100 MPa. The obtained catastrophic fracture paths were non-coplanar with the initial flaw plane. The values of the critical stress intensity factors, KIC and KIIC, were obtained with the ratio KIIC/KIC=1.06 observed. The experimental plots of KI versus KII were compared with the existing theories. A strain energy density fracture criterion best described the mixed-mode fracture.
  • 酒井 信介, 森田 英明, 岡村 弘之, 高野 太刀雄
    1988 年 54 巻 507 号 p. 2061-2068
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    This paper proposes a new algorithm to analyze the three-dimensional (3D) structure of the picture of the scanning electron microscope (SEM) using a personal computer. In order to execute the 3D analysis of a fracture surface, two pictures which are taken from two different beam angles are necessary and the corresponding points in those pictures must be identified. usually, a sequential similarity detection algorithm (SSDA) method or correlation factor method is used in order to identify the corresponding points. The SSDA wethod is widely used because of its simplicity and accuracy. When we use this method with a personal computer, however, the processing time cannot be neglected. Thereforere, we modified the algorithm so as to construct a rational analysis system using a personal computer. The performance of the developed algorithm is compared with ones of the usual SSDA method and correlation method, and good characteristics with respect to speed and accuracy are obtained. Several typical pictures of the fracture surface are analyzed by the developed system and efficiency is shown to be sufficient.
  • 多田 幸生, 松本 隆一, 山本 健二
    1988 年 54 巻 507 号 p. 2069-2073
    発行日: 1988/11/25
    公開日: 2008/02/21
    ジャーナル フリー
    The purpose of this study is to develop a CAD system for frame structures as packing cages. In order to simplify the design works of packing's frame structures and to unify the design criteria for them, the CAD system must support the estimation and setting of loading conditions peculiar to packing cage, which considers loadings in the handlings, transportation and conveyance, and must include the structural analysis and automated design of frames. In this report, firstly, a guiding principle of the system development is described. Secondly, the main parts of the paper are devoted to the reconsideration of the stress analysis and proposition of a simplified optimization method for the savings of steel material costs.
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