-
Article type: Cover
Pages
Cover1-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover2-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Jiro OKAMOTO, Ryoichiro SASANO, Kanenori YOKOTA, Tai MURATA, Mikio FUK ...
Article type: Article
Pages
1-6
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Previously hatch coamings were erected on the decks of the ships bcfore launching. After launching, hatch covers and fittings together with seal bars, rails, oil jacks and pipes were installed and completed on board. On compeltion, hose testings and operation tests were carried out before inclining test and sea trial. In view of the critial planning and processing required within the overall schedule of the ship in the above method of installing coamings and covers, the authors have endeavoured to improve on this method as follows. The unit comprises the hatch coaming and steel hatch covers completed and fittings located in place. The units are constructed in the assembly areas of the shipyard and erected on to the deck before launching.Therefore, work on fittings can be commenced soon after launching. Due to the adoption of this method the authors succeed in completing hatches etc. about two weeks earlier than by previous method, together with an approximate reduction in cost of 40%. At the beginning the author's concern was primarily about quality, and in particular deformation on completion of installation. It was found on completion that deformation was so slight that it could be ignored, proving the quality of the new system.
View full abstract
-
Masaki WATANABE, Taro OKAMOTO
Article type: Article
Pages
7-18
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Recently there has been a tendency that the range for using materials extends to not only elastic region but also plastic region by making them lighter and larger. It is often observed that especially under actual load, the stress over yield point loads on the notched parts, while the structure acts elastically. So it has become necessary more and more to clarify the elasto-plastic behavior of notched material from a view point of design. In this paper, elasto-plastic behavior of SM 50 steel notched bars of three types under tensile and compressive load was analyzed by means of the finite clement method and the behavior of stress-strain distribution and plastic zone was clarified. From the result of the calculation, the conclusion is summarized as follows: 1. The difference of fracture appearances of each notched specimen was explained by the behavior of stress distribution and plastic zone under static load. 2. It was clarified that the required load is constant to develop the plastic region to 0.2mm in depth from the notch surface at the net section of notched specimen regardless of a size of notch factor. 3. The estimation of strength by using Neuber's formula K_t=(K_σK_〓)^<1/2> gives the safe value under general yield load. 4. Stress distribution and plastic zone of tension side and compression side under the first cycle of completely reversed load-controlled test are almost the same. 5. The residual stress decreases with the repetition of cyclic load.
View full abstract
-
Hiroaki IRIMOTO, Genichiro AKASHI, Yoichi NAKAMURA
Article type: Article
Pages
19-27
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In recent years, the dimensions and output of marine diesel engine have remarkably increased, and the size and weight of its parts have gradually dereased in order to get larger cargo space. Then, the axial vibration of the crank shaft becomes important problem to study in connection to the strength of crank shaft and the influence to the hull vibration. Accordingly, various researches and investigations to this problem had been carried out in many organizations and various important results had been obtained concerening the method of analysis and the way to control the axial vibration. In this paper, we describe the results of our investigation, which was carried out as a part of research work of SR 100 in 1967, on the characteristics and effectiveness of a new oil-damper for axial vibration of crank shaft which we produced.
View full abstract
-
Sekio KONISHI, Minoru SAKAO
Article type: Article
Pages
29-36
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
The new circulating water channel,the largest in Japan, has been installed at the Technical Research Laboratory of Kawasaki Heavy Industries, Akashi, August 1971. Here described are the outline of the tank and its characteristic performance. Flow visua1ization and the funfamental ship-hydrodynamic investigation will be the main subject of the tank.
View full abstract
-
Ichiro TANAKA, Hiroshi TAGANO, Yoji HIMENO
Article type: Article
Pages
37-47
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In order to investigate into the characteristics of viscous flow field around a body and its viscous drag in high Reynolds number, the measurement of surface pressure and the velocity and pressure in the boundary layer and wake has been attempted for a body of revolution of length 4m in a wind tunnel. The experiment has been made at the wind speed 15-35m/s. Pressure drag is obtained from the measured pressure distribution and frictional drag is from the velocity distribution in the boundary layer. Discussion is made on the comparison of the results with existing data.
View full abstract
-
Susumu HIRANO
Article type: Article
Pages
49-55
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
The paper seeks to determine what swimming form a dolphin can take when the from is balanced dynamically. The transverse oscillatory movements of slender fish had been theoretically analyzed by M.J.Lighthill. According to the theory, any movements attempted by the dolphin which does not satisfy the equation (3) will automatically produce reactions and recoils. To calculate the reactions and recoils it is convenient to represent the form of a dolphin in a mathematical form. The body is approximated to a paraboloid of revolution, the length-diameter ratio of which is 6.0. The position of maximum diameter is located at 0.4l from the nose (l is the length of the dody), and the caudal fin is replaced by a triangle. The span of the trailing edge is 0.25l. As regards the swimming movements, the follwing assumptions are made. The swimming form is represented by the equation (4) which contains six parameters. The progressive wave length of the swimming movement is equal to l and the amplitude of motion of the tail is 0.25l. To determine a balanced swimming form of the dolphin, calculations of reactions and recoils are worked out for various values of two parameters, b and d. The balanced form is found out approximately and shown in Fig. 12. The values of the parameters are b=0.66l and d=0.015l, respectively.
View full abstract
-
Masao YAMASHITA, Toshio HISHIDA
Article type: Article
Pages
57-64
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Contribution of superstructures having various and different degree of watertightness to the righting of a ship lurching among lateral waves is studied experimentally. According as unit superstructures of box type, even though of non-watertight, are added one on a cylindrical model ship, the model rocovers from the lurch, otherwise it capsizes. Corresponding to watertightness of the unit, there is a certain boundary in the total volume of superstructures at which whether it is capsized or not is distinctly distinguished. Capsizing or not is interpreted enough in words of energy balance. The bounding volume determined from energy balance also coincides with the one from experiment. The bounding volume, of course, inereases to some extent if the watertightness falls. The time required up to capsizing from oncoming of the first wave is shortened more or less for weaker tightness. If a proper volume is chosen, however, the superstructure will contrilbute to rescue the ship from a crisis of capsizing, even when it is not watertight.
View full abstract
-
Masafumi MIYAMOTO
Article type: Article
Pages
65-74
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In the initial design of container ships or car-ferries which are strictly required to keep the time schedule, it is important to evaluate their sea margin accurately. Up to the present day, the value of 10-20% has been conventionally used for sea margin from experience without regard to ship's dimensions, cruising range, season etc. In this paper, the author tries to evaluate the power increase due to waves ,which seems to occupy a main part of the sea margin, and to investigate on approximate formula of Response Amplitude Operator(R.A.0.) and the quantity of thrust increase in irregular head waves. The formula of R.A.O.is derived from analyzing R.A.O.obtained from model tests in regular head waves, to make it possible to calculate mathematically the thrust increase. Values of the thrust increase calculated by this method are compared with values measured on board or obtained from model test, and it has been confirmed that this approximate method is useful to estimate thrust and power increase in the initial stage of design.
View full abstract
-
Masaaki GANNO
Article type: Article
Pages
75-81
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
To calculate the critical line of deck wetness in regular oblique waves, the vertical displacement of ship side relative to wave surface z_r, is obtained considering vertical displacement of the ship side due to heave, pitch and roll. The dynamic swell-up due to heave, pitch, sway, roll and orbital motion of the wave is also taken into consideration. In the meantime, f_s, the relative elevation of water surface due to trim, sinkage and elevation of water surface generated by the ship running in still water is obtained experimentally from model tests. The critical point of wetness is defined as the case when z_r coincides with f-f_s, where f is the geometrical freeboard of the ship.
View full abstract
-
Shiro WATANABE, Tokujiro INOUE, Shiro KAWAMURA, Yasufumi YAMANOUCHI
Article type: Article
Pages
83-93
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
For increasing the safety of a ship voyage, the right information should be offered to a ship's master on her safety affected by environmental conditions such as meteorological and sea state which will be foreseen to be encountered as the ship route is determined. This paper presents a prediction system of ship motion from this point of view. To use this system effective, some experimental computations must be made by a crew himself for various conditions, and so this system is designed to use a shipborne computer. From the prognostic weather map recieved by a facsimile, read a pressure pattern around the wide area where the ship will be, guess a wind field to be, and compute the wave spectra, then evaluating the ship motion from these spectra. These spectra are treated as the sum of the wind sea spectra determined from the narrow time-space information and the swell forecasted from the wide time-space information. The region where the evaluation of ship motion is predicted is bounded by the range which the ship runs before and after 12 hours from the prediction time, and by the sector lies between ±30°from the planned ship's route. The ship motion is cvaluated as the sum of a roll and a pitch, both multiplied by appropriate evaluation coefficients respectively. Morever, these coefficients are to be chosen whether a roll is more important or a pitch due to a route and a type of a ship. The problem which appears in constructing this system's hardware is the input and output parts; man-machine communication part. On the input part, a coordinate reading equipment is developed to read the data from the weather map. As the output part, X-Y plotter is used to express the result in a intuitively clear way. The example obtained by this system is shown as Table 1, and the results are obtained quite satisfactorily in spite of the relatively rough approximation in the software design.
View full abstract
-
[in Japanese]
Article type: Article
Pages
95-98
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese]
Article type: Article
Pages
99-105
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese]
Article type: Article
Pages
106-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese]
Article type: Article
Pages
106-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese]
Article type: Article
Pages
106-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
107-108
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App1-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App2-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App3-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover3-
Published: September 30, 1972
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
