造船協會論文集
Online ISSN : 1884-2062
ISSN-L : 0514-8499
1965 巻 , 118 号
選択された号の論文の34件中1~34を表示しています
  • その2, 任意翼型の特性の計算法
    花岡 達郎
    1965 年 1965 巻 118 号 p. 1-8
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    In this paper, the author presents a simple method for the calculation of the characteristics of a fully cavitated hydrofoil. Some tables of the functions necessary for the calculation are constructed. By using the tables, readers will easily be able to calculate the characteristics of a hydrofoil, which shape is defined by a polynomial in x.
  • 西山 哲男, 笹島 孝夫
    1965 年 1965 巻 118 号 p. 9-18
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The present paper is aimed to develope a more accurate lifting-surface theory of widely bladed propellers by applying the Scholz' technique. Curved flow effect, which is of essential importance in the theory of widely bladed propellers, is obtained in the form of correction ceofficients to the lift curve slope and zero lift angle of the blade element. Further, curved flow correction to the lifting-line theory and the corresponding factor to the Ginzel's camber correction factor are discussed in some details from the standpoint of the present theory. Within the framework of linearization theoretical thrust and torque of propellers are in good agreement with the experimental one.
  • Kaname Taniguchi, Hidetake Tanibayashi
    1965 年 1965 巻 118 号 p. 19-23
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The problem of the root erosion experienced on the propellers of a destroyer which was built in Nagasaki Works was investigated experimentally. Starting from our experience that cavitation erosion on marine propellers is closely connected with unsteady cavitation, we carried out cavitation tests in oblique flow condition. The test results and the observation of the full scale propellers have shown that
    (i) such root erosion can be ascribed to the effect of obliquity of the flow to the propeller, and
    (ii) it can be simulated in the cavitation tunnel with inclined propeller shaft. It is expected, therefore, that cavitation test in oblique flow condition is useful and plays an important role in further investigation into this problem.
  • 中村 彰一, 新谷 厚
    1965 年 1965 巻 118 号 p. 24-35
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Amplitudes and phases of pitching and heaving of three models having simple mathematical ship forms in regular head waves are calculated by the strip method. The solutions to the coupled and uncoupled motions are obtained, and their results are compared.
    Resistance increases of the models in regular head waves with three different wave lengths are also calculated by Maruo's approximate method. A modified method taking into account the effect of forward speed on the vertical velocity of ship sections are also examined.
    The motions of the same models as well as the resistance increase in waves are measured and the results are compared with these calculations.
  • 藤井 齊, 小川原 陽一
    1965 年 1965 巻 118 号 p. 36-47
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In general it is very difficult and needs much time to calculate theoretically the heaving and pitching motions of a ship in waves even if when she is traveling in two dimensional regular waves and in a direction normal to the wave crests. So the authors tried to calculate the ship motions above mentioned by the strip method using the high speed computer IBM 7044, and succeeded to put it into practical use, that is, it became possible to calculate the motions about 6070 conditions of one ship only in 12 minutes and with rather good accuracy.
    We used the equations of motion proposed by Watanabe. Solving these equations, we obtained the added mass coefficients and damping coefficients by curve fitting from the values calculated previously by Tasai's method for the cylinders with Lewis form section. In this way we could reduce the calculating time very much.
    Next we compared our results with Gerritsma's experimental values about Series 60 models, and found that the accuracy of calculation could be improved when the damping coefficient for the heave was corrected for the three dimensional effect. So we estimated this correction factor as the function of block coefficient and nondimensional circular frequency of encounter of a ship to waves, and corrected the calculating manner. The test results at Mitsubishi experimental tank were found to fit to our corrected values very well.
  • Seizo Motora, Masataka Fujino
    1965 年 1965 巻 118 号 p. 48-56
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In this paper, the authors describe the forced yawing technique, especially the mechanism of the yawing oscillator and measuring system, by which the stability derivatives of a ship model are measured.
    In order to compare the derivatives obtained by this method with the ones obtained by the rotating arm technique, the authors carried out the experiments in low frequency range. As a result of these tests, a fairly well agreement between both data was recognized.
    In addition, the authors discuss that what kinds of motions are to be given to a ship model in order to get data more accurately and easily.
  • 田宮 真
    1965 年 1965 巻 118 号 p. 57-65
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    When a ship is rolling in waves with so large mean heel angle that her deck edge is immersed, characteristics of the rolling motion, for example the resisting moment, are very much different from those in rolling about an upright condition.
    Shipping of a large quantity of sea water brings about instantaneous heeling over 30 degrees occasionally and some ships capsize and the others become upright gradually.
    The author describes in this paper some interesting experimental results in relation with abovementioned phenomena, unsymmetrical rolling, and an example of the calculation of resistive moment and forces due to wave making is tabulated for the sake of qualitative apprehension.
  • 笹島 秀雄, 姫野 洋司
    1965 年 1965 巻 118 号 p. 66-70
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    This paper presents a result of theoretical calculation on the resistance law of an arbitrary type of roughness. Rough surface is classified into two types in the high speed range according to fluid dynamical properties. One is the sand roughness and the other wavy roughness. However, to find the general characteristics of arbitrary type of roughness is practically impossible and it is necessary to carry out the model test to know the fluid dynamical property of the particular roughness.
    In order to find the method of extrapolation from the model data to the ship, it is important to know the resistance law of roughness, especially the charateristics of the line Uk/v= constant, where k is the height of the roughness. For this purpose, a calculation was made on the the basis of momentum integral method considering the effect of velocity defect due to roughness. The following simple formula was found to exist between the increase of resistance coefficient of the model ΔCfm, and of the ship ΔCfs.
    ΔCfmCfs= (ΔCfmCfs) 2 with Uk/ν=constant, where Cfm and Cfs are the frictional resistance coefficients of the model and the ship, respectively.
  • Shigeru Sato, Shojiro Okada, Shoichi Sudo, Matao Takagi
    1965 年 1965 巻 118 号 p. 71-83
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In case of oil tankers with large CB and small L/B value, the action of large bulbous bow in contributing to reduction of hull resistance is considered to be somewhat different from the case of high-speed, small CB vessels. Authors examined the results of model experiments in towing tank and in wind tunnel, and results of trial runs of actual ships on large tankers, which were all conducted by Hitachi Shipbuilding and Engineering Co., Ltd., and besides, give some theoretical considerations on them. Consequently, the reasons why a large bulbous bow contributes to reduction of hull resistance were explained, and a guide to design of the bulbous bow was given for large oil tankers.
  • 梶谷 尚
    1965 年 1965 巻 118 号 p. 84-107
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The linearization of boundary conditions both for ship surface & free surface often gives rise to discussion when we seek the relation between ship forms and their wave-making resistance especially of displacement ships. Inui's improvement for ship surface condition is well known as a double model conception. However it still neglects partially the free surface effect except for exactly corresponding zero Froude number case.
    An extention of his idea is examined here to build up a more exact theory by introducing a higher or the second order ship surface approximation taking the whole free surface effect into account. His approach is called stream-line persuit method or inverse method because not ship forms but their equivalent source or doublet distributions are determined first with sometimes the aid of variational treatment of wave-making resistance formula expressed by functional singularity distribution.
    In this paper, two concrete non-zero Froude number hulls corresponding to K0L=14 are obtained to sereve for streamline observation, resistance test and wave pattern comparison. As the result it finds that 2nd order approximation of hulls contributes to the improvement in the theory of wave-making resistance, provided that some disagreement of ship surface condition still remains near the bow.
  • 神中 竜雄
    1965 年 1965 巻 118 号 p. 108-114
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The slender-body theory was applied to calculation of the stream-lines around a ship's hull.
    This method has a merit that the influence of frame-line form on the stream surrounding a hull surface will be appreciated intuitively. The correctness of this approximate theory was ascertained by an application to the Inuiid.
    Besides, the stream-lines around typical hull forms are stated and also the problems caused by the flat bottom are refered to.
  • 豊田 昭三
    1965 年 1965 巻 118 号 p. 115-124
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The purpose of this paper is to report and review how the author applied a high-speed electronic digital computer to the calculation of ship propulsive performance, as a part of the network of the application to ship calculation and initial design problems, which was conducted by Mr. A. Yamagata and Mr. N. Akatsu, a summary of which was presented at the Spring 1964 meeting of Zosen Kyokai1).
    The paper deals with the following calculations : -
    1. EHP estimation using the Design Charts of Series 60 connected with the correction factor “CRD” to an actual ship and Schoenherr's frictional formula,
    2. Initial propeller design using the modified AU type propeller chart,
    3. Power and revolution estimation calculated with the EHP, self-propulsion factors and the characteristic curve of the propeller designed, and
    4. Speed trial results analysis in order to obtain ship-model correlation factors.
    N. B. As for the application of a computer to the design of preliminary ship-lines and the correction of speed trial results against wind and current, the author has already reported in the Journal of Zosen Kyokai, No. 114, 1963 (in English) and the Monthly Journal of Zosen Kyokai, No. 416 (in Japanese) respectively.
  • 石井 信夫
    1965 年 1965 巻 118 号 p. 125-137
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    M. S. Yamanashi Maru, the first of so called “super high speed” vessels of Japan, was built in October 1962, length 150 meters and main engine out-put 17, 500 B. H. P., the service speed at full load condition was 19.7 knots.
    In November 1963, the second vessel “Yamashiro Maru” was completed, 150 meters and main engine out-put only 13, 000 B. H. P., the service speed at full load condition was 19.5 knots. She was designed to gain a high speed even if with low power by the adoption of a new ship-form with a bulbous bow. We were greatly concerned to see if she is capable of navigational performances as designed, approximately same as those of m. s. Yamanashi Maru with an engine output less 4, 500 B. H. P. Upon completion, both vessels were placed in the regular liner service for Europe and we compared their navigational performances on four voyages.
    The result of analysis proved that the Yamashiro Maru showed the successful navigational performances approximately same as that of the Yamanashi Maru, so the “Yamashiro Maru” exceedingly surpassed the “Yamanashi Maru” from the economical view-point.
  • 山本 善之, 在田 正義
    1965 年 1965 巻 118 号 p. 138-146
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Damping for ship vibration is large as compared with that calculated from material damping by the theory of flexural vibration of beams; in most cases the former is ten times as large as the latter. Hitherto the internal friction of materials is considered to play the most imporcant role for damping in the ship vibration. However, the friction of surrounding water and the energy dissipation due to cargoes may have a marked effect on damping. In this paper, the damping forces of these kinds are investigated theoretically and experimentally, it is concluded that the discrepancy between experimental and calculated values of damping in ship vibration is due to frictional forces of water and cargo.
  • 山越 道郎, 大沼 覚
    1965 年 1965 巻 118 号 p. 147-159
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    To make clear the nature of hull vibration of higher mode it is indispensable to investigate the problem of the coupling of hull vibration and local vibration of ships. This problem was investigated already by Prof. Watanabe, Dr. Suetsugu and others in connection with the causes of the stern vibration of ships. In these investigations, however, they analysed the problem by replacing the structure which makes a local vibration with a system of spring and mass. As a first step to investigate this problem more closely, in this paper we have analysed the same problem by treating the bottom structure, the typical structure which makes a local vibration, as an elastic plate instead of replacing it with a system of spring and mass. After this investigation the nature of so-called second spectrum owing to the coupling of hull vibration and bottom vibration of ships have been made clear. We think that the interesting phenomena found in the experiments of box beams and sometimes in the tests on actual ships are closely connected with the two nodes or three nodes vibartion of second spectrum explained in this paper.
  • 寺沢 一雄, 八木 順吉, 森口 恍次
    1965 年 1965 巻 118 号 p. 160-170
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Recently, various kinds of high tensile strength steels have been used in ship structures, and their fatigue strength has also been investigated. However, there have been very few reserches on plastic fatigue strength of thin plates under alternating tensile and compressive loads.
    The experiments on plastic fatigue strength were carried out to clarify the strength of several kinds of steels, and effects of strain concentration and of reinforcement.
    The following specimens were used under alternating tensile and compressive loads.
    1) Plain specimen
    2) Notched specimen (with a hole)
    3) Inserted specimen (inserted with high tensile strength steel around the hole of notched specimen of mild steel)
    For the investigation, three kinds of high tensile strength steels (σB=50 kg/mm2, 60 kg/mm2 and 80 kg/mm2) and mild steel were provided.
    In order to prevent specimens from buckling, a special apparatus was attached on specimens.
    The results of the experiment are summerized in the followings;
    1) S-N curves obtained for alternating amplitude of constant loads have short parallel parts to N-axis, and are different from the results of zero-tension tests.
    2) For plain specimens, higher tensile strength steel has greater ratio of fatigue strength to tensile strength than that of mild steel. And there are linear relations between stress amplitudes and tensile strength at the same fatigue life.
    3) The strength of the notched specimens generally has the same tendency as for plain specimens, but HT-80 has lower strength than HT-60 in the range of long life (N>104).
    4) Fatigue strength of the inserted specimens increases proportionaly to the tensile strength of inserted plates and it's breadth.
    5) In the case of very higher stress concentration at the root of the notch, it may be expected that the fatigue strength of inserted specimens has nearly the same fatigue strength as that of notched specimens of high tensile strength steel.
  • 秋田 好雄, 前田 豊生, 矢田 敏夫
    1965 年 1965 巻 118 号 p. 171-191
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    Initiation of brittle fracture in welded structures was investigated by means of two newly developed testing methods : Transversely Welded Wide Plate Test and Longitudinally Welded I-Shape Test (IHI-Test).
    The Transversely Welded Wide Plate Test brought forth the possibility of brittle fracture along welded joint, so far believed improbable in as-welded structures. Along-weld-line brittle fracture was found occurrable in structures built from a certain type of high-strength steels. The minimum width of test plate should be such that the free edges would have no substantial effects. The mean fracture stress was found largely affected by the configuration of the joint, especially by an angular distortion, as well as by the notch toughness at the fusion zone.
    This fact was given theoretical explanation by calculating the strain at the fusion zone in distorted joint, and by assuming the brittle fracture to initiate when this strain amounts to a critical value, which is dependent on the material and temperature at the zone in question. Theoretical fracture stresses at given temperature of test plates, welded under various welding conditions and with different initial distortions, excellently agreed with experimental values.
    The Longitudinally Welded I-Shape Test reproduced low-stress brittle fracture, initiating from a natural notch in residual stress field, at considerably higher temperat res than what had been expected from existing testing methods.
    In this test, the width of specimen markedly affected the mean fracture stress. This phenomenon was hardly explainable by presuming as in the existing theories that the brittle fracture initiation is governed solely by the magnitude of stress at the notch front; the residual stress pattern around the notch must come upon to play a role.
    The anthors propose an analytical way of estimating stresses for brittle fracture initiation in such a non-uniform stress field. This analysis is essentially in line with the fracture mechanics, except that further consideration is given to the plastic zone size which should be dependent on the distribution of stresses within a certain area around the notch. The theory again excellently represented the observation.
    The herein presented two newly developed testing methods along with the proposed way of analysis lead to a clear-cut description of brittle fracture initiation characteristic to welded structures. Means for preventing such fracture follow at once.
  • 実験的検討
    吉識 雅夫, 金沢 武, 町田 進
    1965 年 1965 巻 118 号 p. 192-203
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In the preceeding reports the authors discussed the effect of crack arresting action of several kinds of crack arrester model with the application of two dimensional elasticity theory of cracked plate. Numerical calculations and some preliminary experiments showed that the brittle crack propagstion arrest could be explained by a relatively simple fracture mechanics criterion based on Kc-concept.
    In this report, a further experimental check was made by large size brittle propagation-arrest test (Double Tension Test) using specimens with patch and rivetted stiffener type crack arresters. The method of analysis described in the previous report was applied to the test results obtained. The experimental results showed good agreement with the estimations from analytical calculations. This verifies the adequacy of the above-mentioned criterion, and provides fracture mechanics interpretation of brittle fracture propagation test and a quantitative approach for brittle crack arrest mechanism and design of crack arresters.
  • 鋼板の破壊発生特性について
    木原 博, 池田 一夫
    1965 年 1965 巻 118 号 p. 204-220
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In the first report, one of the authors succeeded in the brittle fracture initiation at low stress levels from the notch without any additional factors such as the welding residual stress, the impact stress and the metallurgical embrittlement etc. by using the deep notch test.
    In this paper, firstly, a review of the fundamental theories of fracture initiation and the theoretical extension of the results of deep notch test to the brittle fracture initiation characteristics for an infinite plate were made.
    Secondly, the following fundamental experiments on brittle fracture initiation were conducted : (1) Classification of zones for fracture initiation. (2) Applicability of the Griffith-Orowan energy condition. (3) Size of yield zone around the tip of notch. (4) Effect of plate thickness.
    Next, the brittle fracture initiation characteristics for various steels such as the mild steel, various high strength steels including HT 60, HT 70, HT 80, HT100, and various low temperature steels including 2.5% Ni, 3.5% Ni, 9% Ni steels and Al-killed steels quenched and tempered with the yield strength of 33, 37, 58 kg/mm2 were evaluated.
    Lastly, the correlations between the brittle fracture initiation temperature for a crack length of 10 mm under a stress level of σy/2.56 and the transition temperatures in various large and small size brittle fracture tests were investigated.
  • 秋田 好雄, 簑田 和之
    1965 年 1965 巻 118 号 p. 221-233
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Recently, aluminium alloy has increasing been adopted to the welded structure, the more widely use of the higher-strength work-hardened Al-Mg alloy (such as 5083-1/4 H or 1/2 H) would contribute to the weight-reducton of the structures.
    One of the most important problems in the adoption of these alloy to the welded structures is the reduction of joint efficiency due to the softening of heat affected zone.
    The width of softened zone of the welded work-hardened alloy varies with welding conditions it is reduced by using small welding heat.
    From another point of view, the knowledge of the characteristics of these softened zone, would make it possible to cover the decrease of strength due to softened zone by using suitable joint design.
    In this report the author made clear the followings;
    (1) The fundamental nature of welded joints with softened zone by inquiring after the factors most connected with softened of welds and the relation between the width of softened zone and welding heat or tensile strength of welded joint of the work-hardened aluminium alloy, as well as
    (2) The possibility of increasing the strength of structural member including weld softened zone by adopting the appropriate joint design, from the results of tensile tests on longitudinal transverse and combined of shifted cross joints, and the stress analyses there of.
  • 杉村 卓
    1965 年 1965 巻 118 号 p. 234-240
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Recent experimental works in our country on the bodily collapse of ring-stiffened circular cylindrical shells subjected to hydrostatic external pressure are almost concerned with welded and so initially deformed models in order to apply the results directly to the design of submarine hulls.
    But the results can not satisfactorily be explained by the analyses which makes use of exsisting theories, hereby the method of analysis which accommodates to such imperfect models seems to be needed very much.
    This report deals with a method for estimating the collapse pressure which relates to material strength and initial out-of-roundness as parameters. This method is based on the consideration that, when ring-stiffeners have some initial out-of-roundnesses and the model is loaded by uniform pressure, the stiffeners contract gradually while being bent in a certain circumferential mode, and finally when at least three plastic hinges occur at the adjacent positions on them, the stiffeners collapse locally and immediately after that a total model collapses generally. Some experimental results are refered to ascertain this method.
  • 本間 康之
    1965 年 1965 巻 118 号 p. 241-248
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    The elastic shell buckling of a circular cylindrical shell caused by a briefly applied, intense pressure loading is considered.When such cylindrical shells as these produce the elastic shell buckling by the hydrostatic pressure collpse under the transient load, it may be thought that the elastic buckling of the shell occure at the early stage of the collapse.
    Such a elastic buckling pressure is able to calculated by the method of minimumization of the total potential which is the sum of the elastic strain energy in the shell, the kinetic energy of the shell and the work done by the external forces acting on the shell, that is, the equation of the motion on the shell is obtained from the first variation of the total potential, and the second variation determines the critical pressure at which the elastic instability of the shell will occure.
    The calculating result as follows, qs4/n22+1/12 (1-v2) h2/a2 (n22) - (n22/2) q02/k2/ [n2 (1-cos kt) -1] +2/ (n22) 2 [n2 {n2+ (2+v) α2} cos kt2 (n2-vα2])
    where Ps =critical transient pressure (asumming that the load-time relation is square)
    P0=static pressure
    q0=P0a/Eh
    n=number of lobes
    α=πa/b
    a=radius of cylinder
    b=length of cylinder
    h=thickness of cylinder
    k2=Ega2
    γ=density of shell material
    λ=ratio of the velocity of buckling deflection to the buckling deflection
  • 吉識 雅夫, 山本 善之, 近藤 尚夫
    1965 年 1965 巻 118 号 p. 249-258
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Many parts of ship structures, such as bottom plating, are subjected to edge thrusts and lateral pressure at the same time, In this paper, the behavior of a plate under increasing edge thrusts and constant lateral pressure is investigated. Such a plate deflects from the beginning, and the deflection increases continuously with load. When lateral pressure is large enough, the deflection pattern is similar to that due to lateral pressure alone, and any definite critical state does not appear. When the lateral pressure is small, buckling pattern appears under the edge thrust of a certain value. Such behaviors are investigated theoretically and experimentally, and a good accordance between the theory and the tests are obtained. Within the elastic range, the critical value of edge thrusts usually increases with lateral pressure. When the plate is stressed beyond elastic limits, the critical stress is lowered by the effect of plastic deformations.
  • 秋田 好雄, 高田 健, 潮田 史郎, 松澤 摂津男, 片岡 軍司
    1965 年 1965 巻 118 号 p. 259-270
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    Nuclear powered ships must be safe from collisions at sea but, in event of a collision, the dangerous uncontrolled release of radioactive or toxic materials must be guarded against and prevented.
    For this purpose, we carried out a series of experiments with models of bow and side construction, and investigated the results.
    The following is a summary of the experimental studies carried out on the collision barrier and the important part it plays in protecting the reactor plant on board.
    1. It is sufficient to compare the strength of the bow construction, when it strikes a solid wall, with that of the side construction, when it is struck by a solid bow, in order to compare the strength of a bow construction with that of a side construction at the point of collision.
    2. A vessel with a raked bow is not so dangerous compared as a vessel with a vertical bow.
    3. The deck plate will absorb a certain amount of energy ever after the shell has been penetrated. This amount can not be considered negligible.
    4. About the impact loading effect, it is only necessary to correct the yielding point of the matelials by the strain rate.
    We must derive the more complete formulas for calculation of the energy absorbed by collision barriers by farther studing the effect of the entrance angle of striking vessels.
  • 吉識 雅夫, 川井 忠彦
    1965 年 1965 巻 118 号 p. 271-278
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    Applying the general method of solution proposed in the preceding paper, two important vibration problems frequently encountered in shipbuilding practice will be studied, the first of which is rectangular plates whose edges are intermittently welded to rigid girders or frames and the other is a perforated rectangular plate. Taking several examples, numerical analysis was extensively carried out and comparison between their results obtained and that of other investigators duly showed practical applicability of their method.
  • 川井 忠彦, 吉村 信敏
    1965 年 1965 巻 118 号 p. 279-289
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    In the previous report, general description on the influence functions of a given plate and their application to plate problems was indicated. Then two classes of new influence functions are introduced and their fundamental relations are discussed. The method of application of those new influence functions to initial stress problems of infinite as well as semi-infinite plates were illustrated.
    In this report, influence functions for deflection of a rectangular plate are derived first for two different cases of boundary conditions, and newly introduced influence functions of the plate under concentrated hydrostatic pressure and couple are determined.
    From these functions, influence functions for infinite plate strips of two different boundary conditions are derived and application of these functions to initial stress problem are illustrated with numerical examples.
  • 二脚マストの塑性設計
    藤田 譲, 藤井 登喜男, 吉田 宏一郎
    1965 年 1965 巻 118 号 p. 290-298
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    Iu the previous plastic analysis of bipod-type mests, the collapse of the mast had been treated to occure in the plane of the masts or perpendicular to the plane.
    In this paper, the collapse by the loads of which direction has an arbitrary angle to the plane of the mast are dealt with by using two different yield condition i. e., a spherical and a polyhedral yield surface.
    Experiments were carried out on twelve specimens and these results were compared with the theoretical results.
    The following were obtained conclusively.
    (1) The collapse load calculated by using a spherical yield surface is higher by about 10% than by using a polyhedral yield surface.
    (2) Experimental collapse loads coincided well, except particular cases, with the theoretical results by using a spherical yield surface.
    (3) As the collapse loads calculated by using a polyhedral yield surface are in the safety sice by about 10%, this surface may be adequate to the actual design, thinking that the calculation is simpler.
    (4) It is clarified that the collapsing load of mast subjected to the load having skew angle, is not so less than that subjected to the parallel or perpendicular.
  • 塑性域における構造要素の圧縮強度
    吉識 雅夫, 藤田 譲, 吉田 宏一郎
    1965 年 1965 巻 118 号 p. 299-306
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Plastic design methods assume that local buckling of flanges and webs of menbers will not occure during the formation of plastic hinges. In view of such a fact, plate buckling in the plastic range becomes a foundamental problem to determine the dimensions of the members. In this paper, so-called “Δ2-method” which gives experimentally the critical value of elastic plate buckling is extended to plastic plate buckling problem, and a new method (ε-Δ2 method) is introduced in order to obtain the experimental buckling load of plastic buckling of the uniformly compressed plate. This new method bases on the linear relation (the average compressive strain) and Δ2 (the deflection of plate) after plate buckling. Moreover, the compression tests of fifteen short angles with various b/t were carried out. The critical values experimentally decided by ε-Δ2 method, were compared with the theoretical values. As a result of the comparison, the following were obtained conclusively.
    (1) From the theoretical calculation, the average compressive strain of uniformly compressed plate into plastic range are approximately linearly related with the square of the deflection Δ2 after buckling.
    (2) The experimental values of the angle tests clarified such a matter that was mentioned in (1).
    (3) The experimental values of the angles coincided well with the theoritical values.
    (4) The value of b/t necessary to prevent plastic plate buckling until the strain reaches to the strain hardening zone, was about 67 for 70 (kg/mm2) high tensile steel and about 7.5 for mild steel, and generally the higher the yield stress, the smaller the required value of b/t.
  • 突合わせ溶接接手に生ずる過渡応力ならびに残留応力について
    辻 勇
    1965 年 1965 巻 118 号 p. 307-317
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    Thermal stresses induced by butt welding of two plates are studied, based on the elastoplastic theory in which temperature dependence of yield stress and workhardening of the plate material are considered. For simplicity, uniaxial temperature distribution varying with time is assumed. Numerical calculations are carried out using a step-by-step procedure in time by means of a digital computer.
    The transient and residual strains, stresses and zones of plastic range are elucidated, and then, effects of hardening rate and heat input on the thermal stresses are investigated in detail. All the results are illustrated in figures using dimensionless quantities.
    Main conclusions obtained are as follows.
    (1) It is found that some central regions are subjected in turn to plastic yielding in compression and in tension whereas other major portions of the plate behave in an elastic manner throughout the cycle as shown in Fig. 7. There is a time interval in which plastic loading and unloading occur simultaneously.
    (2) Variations of the transient stresses with time for the different combinations of a hardening rate and an amount of heat input are as shown in Figs. 9 and 12.
    (3) Growth patterns of the plastic regions are not affected substantially by the hardening rate, but the magnitude of maximum tensile residual stress increases almost proportionally with increasing hardening rate.
    (4) As the amount of heat input increases, the plastic regions widen and the absolute value of uniform compressive residual stress increases as well, but the magnitude of maximum tensile residual stress tends to decrease slightly.
    (5) The magnitude and distribution of residual stresses developed by an arbitrary welding conditions may be evaluated approximately by use of Eq. (8), Fig. 10 and Figs. 1315. Some trials by use of these results are good in accord with the experimental data.
  • 中野 有朋
    1965 年 1965 巻 118 号 p. 318-327
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    In order to reduce the airborne and the solidborne noise in the ship compartments, it is important to know some acoustical properties, such as, “abstrahlfaktor”, transmission loss, and damping effect of joiner structures for the ship.
    In this experiment, using a coupled reverberation room, the measurement of these properties were made through the sample 2m×1m in size, of several types of fundamental joiner structures, excited by the airborne noise.
    In accommodation spaces, which may be predominantly excited by the solidborne noise, the average sound pressure level radiated in the room by the surrounding wall vibration will be calculated by the abstrahlfaktor, average absorption and the velocity level averaged over the wall.
    This calculated level will be the upper limit practically expected in this room.
    In engine room, which may be largely excited by the airborne noise, the level will be calculated by usual way of using transmission loss.
    As for the velocity level and their distribution in the ship compartments, further investigations are to be made.
  • 角オリフィスの特性および丸ダクト分岐部分流特性に関する研究
    樋口 道之助, 瀬川 正人
    1965 年 1965 巻 118 号 p. 328-336
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    This paper deals with results of tests made on the following matters.
    (1) The flow through the rectangular orifice fitted on a rectangular air duct.
    (2) The divided flow at the tee branch for a circular air duct.
    As the results of expeiments, the following empirical formulae have been obtained
    (1) Coefficient of resistance at the rectangular orifice.
    ζ= (AdA0-1) 2
    α=0.625+0.375 (A0/Ad) 3
    (2) Loss in the divided flow at the tee branch for a circular air duct.
    Main duct P=0.05 Hm 0.6 S2Hm
    Branch duct P=0.99 Hm+0.341 Hb
    Where
    ζ=coefficient of resistance
    A0=sectional area of orifice
    Ad=sectional area of duct
    P=pressure loss, mmAq
    Hm=velocity head in the main duct, mmAq
    Hb=velocity head in the branch duct, mmAq
    S=flow quantity ratio
  • 沢村 鶴松
    1965 年 1965 巻 118 号 p. 337-347
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    At the beginning of the initial design of ship, the breadth of ship has been determined by the formulas B=L/10+α (α=4.56), B=L/9+β (β_??_3.2) or L/B ratio (6.57.5 for cargo boat). But the above formulas have no connections with KG, GM and the freeboard. The author has delived the relation between B and D from the GM equation. The result is as following.
    [2Q/GM (d/D) D+1] 2-4QP/GM2 (d/D) 2B2=1
    where
    P=Cw/Cb (0.0106+0.0727 Cw) =1/R
    Q=n (d/D) - (d/D) 2Cw/Cb+Cw
    The above equation is a hyperbola of B and D. So B can be put for an asymptote of this hyperbola.
    B=√RQ/L/Dratio·L+GM (d/D) √R/4Q where L=D×L/D ratio.
    The above equation can be expressed as following.
    B=L/const1+GM+ (d/D) const2 (1)
    Flush DK Shelter DK Three isl Well DK Oil Tanker
    (KG/D) (0.60) (0.60) (0.65) (0.52)
    Const1 8.38.7 7.78.2 8.48.8 12.513.2
    Const2 4.64.5 4.54.4 4.2 5.7
    Fore figure is U shape, aft figure is V.
    The const1 varies by the D/d ratio and KG/D, but the const2 varies very small.
    When the second term of the equation (1) is large in case of an oil tanker, a correction value [= (the second term of eq (1)) 2×1/2B] must be subtracted from B in the equation (1).
    The author has drawn the curves of R and Q for the general application.
  • 小沢 尚介, 弓削 篤, 三浦 冨士雄, 須藤 正信
    1965 年 1965 巻 118 号 p. 348-357
    発行日: 1965年
    公開日: 2009/07/23
    ジャーナル フリー
    The new Antarctic Observation Ship has certain features such as a semicircular bottom and a large lunching weight considering the hull scantling.
    To enable the lunching of this vessel to be successfully carried out, the lunching berth was extended some 40 M into the sea and this was accomplished by using 6 flaoting tanks, which operated on steel balls. We summerize here about the enforcement of the plan for this vessel.
  • 小田 道隆, 梶原 儀親
    1965 年 1965 巻 118 号 p. 358-368
    発行日: 1965年
    公開日: 2010/01/20
    ジャーナル フリー
    In this report, three subjects will be dealt with. First, an example of variation of transverse shrinkage of ship's bottom plating during progress of hull welding will be illustrated, which variation of shrinkage somewhat resembles that found in fore & aft direction.
    Secondly, an attempt will be made to explain results observed in actual cases of ship construcition which indicated that the ship's bottom deformation such as the rising of the stern was caused chiefly by welding the bottom in the vicinity of the deformation and was little affected by welding of the main deck & structures above the main deck.
    The third and major discussion will concern the influence of ship's deformation on the propulsion shafting. When main propulsion shaft bearings are out of line, many troubles should be anticipated, such as shaft failure, extraordinary wear-down of bush or bearings, vibration or whirling, and loss of power etc.
    Regarding the problem of untrue shaft bearing, the variation of bearing reactions and the bending moments in shafting corresponding to various alignment conditions were calculated on one ship. The comparison of the resulting calculations led to the conclusion that the most important thing is to equalize the bearing reaction and bending moment of shafting everywhere as much as possible. It is only of secondary importance to maintain all bearings on straight line.
    Another conclusion resulting from the calculation is that a faired deflection of bearing position such as deformation due to ship's hogging or sagging, even if the amount of deviation of bearing position from a reference line is remarkably large, will do little harm the shafting. Rugged deformation such as in case of stern bush wear-down or local deformation due to welding will be harmful to the shafting.
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