Transactions of the Japan Society of Mechanical Engineers
Online ISSN : 2185-9485
Print ISSN : 0029-0270
ISSN-L : 0029-0270
Volume 23, Issue 131
Displaying 1-21 of 21 articles from this issue
  • Kazuto TOGINO
    1957 Volume 23 Issue 131 Pages 429-430
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    Download PDF (407K)
  • Hiroshi MIYAMOTO
    1957 Volume 23 Issue 131 Pages 431-436
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    A methd of solution is proposed to solve the problem of the theory of elasticity for a region containing more than two spherical cavities, extending the method utilized by A. E. Green for plates with circular holes. The method consists of the simple expression of harmonic function referred to a spherical coordinates by the sequences of those referred to another one. The solution is based upon the Boussinesq stress-function approach, and a series solution is obtained for the problem of elasticity for a region containing more than two spherical cavities whose centres lie on a line. Numerical evaluations are given for the stress distribution along the boundary of cavities when the elastic body is under a uniform tension in the direction of centre line.
    Download PDF (695K)
  • Hiroshi MIYAMOTO
    1957 Volume 23 Issue 131 Pages 437-443
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    As stated before when the cavities approach to each other, the stress concentration factor (s.c.f.) of elastic body with two spherical cavities cannot be obtained by theoretical calculations. It is obtained, however, by an experiment of three dimensional photoelasticity. Results are as follows : (1) The s.c.f. K of elastic body with two spherical cavities is expressed by an equation : [numerical formula]where K0 : s.c.f. with a spherica1 cavity. α : s.c.f. of plate with two circular holes when d/p is same as K. α0 : s.c.f. of plate with a circular hole. (2) The s.c.f. K(d/D, d/p) of circular cylinder with two spherical cavities is expressed by an equation : [numerical formula] where d : diameter of spherical cavity. p : pitch. D : diameter of cylinder. (3) When the two spherical cavities approach to each other, the s.c.f. of spherical cavities may be expressed by that of equivalent spheroid.
    Download PDF (1059K)
  • Tadasi ISHIBASI
    1957 Volume 23 Issue 131 Pages 444-447
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The stress system at the neck of a round tension test specimen is analysed by Bridgman and Davidenkov et al. by ignoring the elastic strain components. In this paper the effect of elastic strain on this stress system is discussed. The problem is linearlized for the sake of simplicity. It is confirmed that at the neck, unlike the results hitherto published, the radial and circumferential stresses are not equal to each other. The effect, however, of elastic strain on the maximum axial stress which occurs at the centre of the neck is small so long as the radius of curvature in the region of the neck is large. Referring to the experiment of Parker et al., who discussed experimentally the stresses at the neck after necking begins, it it suggested that the plastic strain in the portion of the neck will be uneven over the cross-section.
    Download PDF (583K)
  • Yoitiro TAKEUTI
    1957 Volume 23 Issue 131 Pages 447-455
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In previous papers we dealt with the two-dimensional stress problems in isotropic plate solved only by harmonic function. The object of the present paper, however, is to show that the above solving method can be extended to the case of the orthotropic plate by means of combining with Takeuti's method and Green's. For illustrative purpose, we solved the stress concentration problems of the infinite plate with a hole ; circular hole and elliptical hole loaded with many concentrated forces acting on the periphery with arbitrary inclinations. Closed-formed expressions of the solutions are obtained by using Dirac's delta-function.
    Download PDF (1027K)
  • Yoitiro TAKEUTI
    1957 Volume 23 Issue 131 Pages 455-463
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    As in previous papers, in the present paper an attempt is made to apply the stress concentration problems due to a square hole in orthotropic plate. Numerical work is carried out for the two stress concentration problems : (a) Hole loaded with many concentrated forces acting on the periphery, and (b) Hole in plate which is subjected to uniform tension.
    Download PDF (951K)
  • Bunzai AN
    1957 Volume 23 Issue 131 Pages 463-467
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In the previous paper, the author proved that approximate solution of elastic problem reduced by indentation of free surface of elastic boby on a rigid medium by a rigid flat-ended cylinder was given by suitably using a solution in the problem of semi-infinite solid, and it held for case in which thickness of elastic body on rigid medium was not so thin. In other words, if the thickness is not so thin, then solution is approximately equal to the result of problem of semi-infinite solid. However, it cannot hold when thickness is so thin. The present paper is to find that solution for the case when elastic body on a rigid medium is relatively thin, with the aid of the previous paper and experimental results as well. In the particular case when thickness is infinite, the results reduce to the semi-infinite solid problem.
    Download PDF (646K)
  • Toshinori KORI, Ryuiti MASUO
    1957 Volume 23 Issue 131 Pages 468-474
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    One of the authors has already published the results of the researches about the stress distribution of powder pressed in a cylinder. According to one of these results, the displacement at the top of the powder is proportional to the load in the second loading until the second load reaches the amount of the first loading. So we can assume that the powder which is pressed once becomes elastic and we can calculate the stress distribution in it by the same method as that of the elasticity. At the previous research, as we assumed the pressed powder was isotropic, we could not calculate the stress in anisotropic powder. On the other hand, it is considered now that even if the powder is isotropic before it is pressed, its elastic property after being pressed in the direction of the axis of the cylinder is not the same as that in the direction perpendicular to the axis. Now this time, we determine the stress distribution under the assumption that the powder is anisotropic and obtain more correct results.
    Download PDF (750K)
  • Makoto ISHIDA
    1957 Volume 23 Issue 131 Pages 474-479
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The problem is treated by the method of perturbation, and convenient formulas for the stress are given in forms of power series. Stress distributions are calculated for some sectional forms, and they are shown to be rather different from the results given by T. Sugihara neglecting the boundary conditions of the horizontal surface.
    Download PDF (751K)
  • Yoshimaru YOSHIMURA
    1957 Volume 23 Issue 131 Pages 480-484
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    Ever since the so-called slip theory was proposed by Batdorf and Budiansky in 1949, it has become a subject of discussion and is not yet settled which of the theories should be valid, the slip theory or the incremental strain theory. In the present paper, the characteristic shear function introduced by them is computed for the two fundamental loading processes, tension and torsion of circular tubes, and accordingly it is shown that the function assumes different values in each case, consequently that the slip theory is invalid.
    Download PDF (651K)
  • Kichiro ENDO, Hiroyasu HUJII, Shunji OMORI
    1957 Volume 23 Issue 131 Pages 484-488
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The corrosion fatigue strength of wires of 0.75% C-steel is presented, relating to the residual stresses. Steel wires as drawn which have high tensile residual stress, wires annealed at 250°C after cold drawing to decrease the residual stress, wires annealed at 630°C after drawing to vanish the residual stress, and wires surface rolled after annealed at 630°C which have high compressive residual stress were tested under rotating bending in stream of city water. The corrosion fatigue strength is lowered by tensile residual stresses and is improved considerably by compressive residual stress. The influence of residual stress on fatigue strength is more remarkable under corrosive circumferences than in air. The corrosion fatigue tests of wire strands are also made.
    Download PDF (910K)
  • Tadakazu SAKURAI, Tadashi KAWASAKI, Yukizumi KITA
    1957 Volume 23 Issue 131 Pages 489-494
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The low-temperature-quenching (LTQ) is greatly effective on improvement of the mechanical properties, especially of the fatigue strength, of steel. The effect of the LTQ on the increase of the fatigue strength is more remarkable in specimens with notch than in plain specimens. This reason is as fallows : (a) The strengthening of the ferrite by aging during repeated loading must be more remarkable due to the sharp concentrated stress at the notch root. (b) Before the formation of fatigue cracks at the notch root, there appears a region which resists the creation of cracks. This region is not only strengthened but also expands inward more and more by repeated loading in the low-temperature-quenched specimens. (c) When a fatigue crack is once formed, the resistance against its propagation is greater in specimens with notch than in plain specimens.
    Download PDF (873K)
  • Zenji ANDO, Sadasi NISINO
    1957 Volume 23 Issue 131 Pages 495-499
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    We measured the micro-Vickers hardness of 0.13%-carbon steel, which had been subjected to a rotatory bending stress. The hardness testing was held under 50 gram and l000 gram loads. Summary of the results is as follows : (1) The increase of the hardness number of ferrite is not always dependent on the magnitude of the repeated stress at the measuring point and the number of stress cycles. (2) The hardness number of the ferrite, which has been increased by the repeated stress lower than the yielding point, is reduced to the hardness of the centre of the cross section by annealing at 600°C for three hours. (3) But the same heat-treatment cannot recover the hardness of the pearlite at the same condition to the previous state.
    Download PDF (799K)
  • Koshiro KUROKI
    1957 Volume 23 Issue 131 Pages 500-506
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In the Rockwell hardness testing of plastics, the relations between diameters of balls, initial load, main load and the depth of indentations were investigated. At the same time, the behaviors of plastics for loading and unloading were clarified. As a result, we have found that the hardness values given by ASTM A and B methods indicate some different properties of materials from each other. For finding the true depth of indentation, electric inductance gage was designed. The hardness values measured by this gage for several kinds of plastics were analyzed by statistic methods, showing the posibility of changing the dial gage for the new gage.
    Download PDF (870K)
  • Shuro MACHIDA
    1957 Volume 23 Issue 131 Pages 506-512
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In this report, the effect of the distance between impact indentations of the diamond hammer of the Shore scleroscope on hardness number was investigated. The experiment was carried out with a Shore scleroscope of D-type and many specimens which were different in hardness or in material. It scarcely need be mentioned that the general requests for testing were satisfied in this experiment. Especially operating conditions of the tester were carefully maintained constant throughout this experiment without being effected by the speed of the operating handle and the force, with which the specimen is pressed. As a result, the effect of the distance between impact indentations on hardness number was made clear. That is, under sufficient pressing force to the specimen, this influence is put in order by the diameter of impact indentation of the hammer generally. Hardness number is not influenced by the neighbouring indentation close up to a half of the diameter of the indentation. Nevertheless, in pratical measuring, it is desirable to measure at a point apart from other indentation as long as possible, and to check the indentation after measuring when measuring is done at a point near to the neighbouring indentations. And also, changing behaviour of hardness number when measuring was repeated at the same point was represented in this report.
    Download PDF (1042K)
  • Shuro MACHIDA
    1957 Volume 23 Issue 131 Pages 512-518
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In this report, the effect of inclination of the tester on Shore hardness number was investigated. The experiment was carried out, with 3 Shore scleroscopes of D-type, on many specimens which were different in hardness or in material. It is needless to mention that the general requests for testing were satisfied in this experiment. Especially operating conditions of the tester immune from the effect of velocity of the operating handle and of pressing force to the specimen, were carefully maintained constant throuout this experiment. As a result, the effect of inclination of the tester on Shore hardness number was made clear. That is, on the whole, the behaviour of this effect is separated into 3 sections. Namely, 1st. is a horizontal line section where hardness number has no change, 2nd. is a inclined line section where hardness number dropes at constant rate, and 3rd. is a curved line section where hardness number takes a sudden drop. This effect is strongly influenced by structure of the tester, dimensions and finishing grade of its parts. And, the regulating apparatus, attached to the Shore sc1eroscope, to keep the tester vertical was proved almost sufficient.
    Download PDF (1047K)
  • Tatuzi SIMIZU, Masatoshi IDE
    1957 Volume 23 Issue 131 Pages 518-522
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    There are two or three equations in the past on the relation between the percentage of elongation and area contraction, but we showed, basing on by another idea, certain new equations expressing the relation between the both on the 4th test piece defined in JIS. That is, a General Contraction ψg% was considered in addition to a minimum contraction ψm%. It is the area contraction of a section that lies at a distance of 3/2 D0 mm from the minimum sectional area on the longer piece after the test, where D0 is a diameter before the test. Then we have obtained three equations on the relation between δ and ψm, ψg, where δ is the percentage of elongation, and it has been found that the calculated values of elongation by these equations coincide well with the measured values. In the three, the following equation is easily applicable to determination of elongation.[numerical formula]
    Download PDF (697K)
  • Minoru HAMADA, Haruki KONDO
    1957 Volume 23 Issue 131 Pages 522-528
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    Natural transverse vibrations of rhomboidal plates with all edges clamped are considered in this paper by the method which was used by Trefftz in the buckling problem of square plate. As numerical examples, fundamental frequencies of rhomboidal plates for several inner angles are calculated. Conversency of the solution becomes worse as the inner angle goes apart from 90°C, but all numerical results calculated here are considered to be within accuracy required for practical purposes, and they can be checked by experiment.
    Download PDF (816K)
  • Yoshikazu SAWARAGI, Hidekatsu TOKUMARU
    1957 Volume 23 Issue 131 Pages 528-532
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The vibration test of the rubber samples is performed with a forced resonance vibrator. The sample is circular cylinder (10φ×60), both edge planes of which are cemented to the platens. The variations of dynamic modulus Ed (appearent value) and internal friction ηω with the initial strain (0∼30% in tension side) are investigated under constant temperature, frequency and impressed force. The following results are obtained. 1. Both Ed and ηω decrease with the increase of initial strain. 2. However, the ratio ηω/Ed remains unaffected with the change in initial strain. 3. The ratio of the static modulus to Ed is independent of the initial strain. 4. The larger the stiffness of the sample, the larger the rate of the decrease of Ed to the increase of initial strain.
    Download PDF (716K)
  • Tsutomu Fujino, Keisuke Kono
    1957 Volume 23 Issue 131 Pages 532-537
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    We experience sometimes the failure of turbine blades of about tencentimeter long caused by fatigue due to the vibration. The cause of this phenomenon is considered to be due to the resonant vibration of the fixed supported normal vibration of the blade system, whose blades are interconnected by a shroud on their top ends, excited by the periodic force owing to the wake of steam flow passed the nozzle. When the length of the blades becomes the length above mentioned, the resonance occurs most probably.
    Download PDF (738K)
  • Masaru TAKATA
    1957 Volume 23 Issue 131 Pages 538-545
    Published: July 25, 1957
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The Dynamic bending stress or moment of an initially curved elastic bar subjected to an axial impact by a rigid mass is calculated approximately and the result is applied to a rod of rock drill. It may be said that the rod of rock drill receives small bending stresses due to initial curvature, compared with the longitudinal one, but the stress due to the eccentric blow is rather large and comparable with the longitudinal one.
    Download PDF (961K)
feedback
Top