西部造船会々報
72
選択された号の論文の41件中1~41を表示しています
  • 原稿種別: 表紙
    p. Cover1-
    発行日: 1986/08/25
    公開日: 2018/02/25
    会議録・要旨集 フリー
  • 原稿種別: 表紙
    p. Cover2-
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 付録等
    p. App1-
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 付録等
    p. i-v
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • [記載なし]
    原稿種別: 本文
    p. A1-A2
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 坂田 則彦, 高岡 慎, 山崎 隆介
    原稿種別: 本文
    p. 1-13
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The accuracy of structural strength and forced vibration analysis depends on the accuracy of wave force estimation. The wave force shows non-linearity by the effect of shallow water, wave profile, relative velocity and acceleration between leg and water particles by vibration. In the previous paper , the considerations of these non-linear effects are omitted but the jack-up rigs mainly operate at relatively shallow water less than 100m and the wave forces on legs between crest and trough of wave profile show the remarkable non-linearity. Additionally, the relative velocity and acceleration also cause the non-linearity for wave exciting force. In this paper, the structural analysis methods how to consider these non-linear effects are presented and their effects to the structural characteristics are studied and the permissible limits not to be necessary to consider these effects are discussed from the practical design point of view.
  • 坂田 則彦, 高岡 慎, 山越 道郎
    原稿種別: 本文
    p. 15-26
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The jack-up rigs tend to sway by the lateral force of wave, current and wind and the relatively large deformations are expected to occur on legs but the effects of these large deformations to the structural strength characteristics has not been studied so deeply until now. In addition to the large deformations of legs, the sea bed behaves as elastic/plastic springs and the sea bed plastic deformation affects the leg deformation to become larger. Namely, their effects to structural characteristics are amplified each other. Recently, the classification society requests the builder to check these effects in case of design of the super jack-up rig for deeper water operation and the simplified strength analysis method in required to be established. In this paper, the new strength analysis method considering large deflection of legs is presented and its effects with combination of sea bed plastic deformation is discussed by the results of numerical calculations.
  • 古金谷 圭三, 伊藤 隆規, 岡本 太郎, 白神 弘尚, 中園 博, 礒部 俊雅
    原稿種別: 本文
    p. 27-34
    発行日: 1986/08/25
    公開日: 2018/02/25
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    It has been sometimes reported that cracks occured at the connection between a lower stool of transverse bulkhead and tank top plate in way of ballast hold of large bulk carriers. As a repair wark, scallops at the connection were covered by collar plates to relax the stress concentration there. In this paper, studying the mechanism of the crack initiation through the fatigue strength analysis, the method of the repair work is prooved to be effective and the guideline to prevent this crack from occuring is introduced.
  • 辻 勇, 井手 敏治, 小柳 雅博, 渡利 久規
    原稿種別: 本文
    p. 35-47
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The boundary integral formulation of the two-dimensional thermoelastoplasticity problem is presented employing linear interpolation functions for boundary elements as well as for internal cells. The semi-analytical approach proposed by Telles and Brebbia is utilized to derive derivatives of the singular integral and to compute its principal values. It is shown that stresses on the boundary can be easily evaluated by applying the Duhamel-Neumann analogy. Some numerical calculations are made to the specific problem of centrally heated disk using two types of interior cell discretization. The boundary element solutions of the thermoelastic analysis agree well with the analytical solutions even if the coarse mesh type is used. In the thermoelastoplastic analysis, three different values of equivalent plastic strain increments are used as the prescribed convergence criterion during iterative process. Then, the accuracy of the calculated results and CPU-times are compared. In order to obtain reasonable results of displacements, strains and stresses, it is concluded that the use of relatively fine mesh of interior cell discretization especially in plastically deformed region is more preferable than precise evaluation of the plastic strain increments at each nodal points during the iterative process.
  • 福地 信義
    原稿種別: 本文
    p. 49-58
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Analyzing collapse of a bow structure of ship generated by a wave impact, the approximate method is usually used to replace a shell structure with an arch or a folded plate structure. However, the behaviour of shell structure subjected to large deflection is considerably different from that of simulated arch or plate with respect to interactive effect of double curvatures. The elasto-plastic analysis of shell has complex problem with nonlinearity about geometric and material in which the solutions on stress and deflection are required to be same level of accuracy. One of universal and powerful method for this subject is a finite element method using hybrid or mixed models that generally has inconvenience to be necessarily extensive calculation due to a large number of freedom. This paper presents an improved finite strip method for elasto-plastic analysis of shallow shell to lighten the volume of calculation. In this method, the displacement functions of strip elements are employed the approximate functions based on a governing equation of shallow shell in order to obtain the solutions with a high accuuracy in spite of using a few freedom. Furthermore, the elasto-plastic analysis on three kinds of shells is carried out by use of the proposed method. By the results of examinable analysis, the relations between initial curvatures of shell or yielding stress of material and behaviour of deflection are clarified and the mechanism of resisting external force in shell is considered.
  • 小柴 幸雄
    原稿種別: 本文
    p. 59-64
    発行日: 1986/08/25
    公開日: 2018/02/25
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    This paper presents a method to estimate the viscous pressure resistance of a ship. First of all, the difference between the pressure calculated by the Hess-Smith's method and the measured pressure is examined on the aft part of some model ships. Through the analysis of this result, a method to estimate the pressure on the stern hull is proposed. Next, the viscous pressure resistances are calculated for some model ships by the integral of the estimated pressure, and compared with the experimental results. As a result of examination, it is found that the present method gives the useful information about a viscous pressure resistance of a ship.
  • 経塚 雄策, 大楠 丹, 稲田 勝
    原稿種別: 本文
    p. 65-73
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Short crested waves to be generated in our towing tank are two long crested waves superposed, which propagate to two different directions. A model ship running on the centerline of the tank does not oscillate transversely when nodal lines of short crested waves are of even numbers. Added resistance of a ship in such waves could be measured as accurately as in head waves. It seems that added resistance in oblique waves could be approximated by that in short crested waves of even nodes because it is not so much affected by transverse motions of the ship as already shown in several published literatures. In this paper, we present results of experiments on added resistance of a ship as well as its motions in short crested waves. They are compared with the prediction by two theories given by Gerritsma et al. and Maruo et al. Response functions of the ship motions in short crested waves, estimated by using strip theory (O.S.M.) agree well with the measured in our experiments. The two added resistances theoretically computed also agree with the measured except in the range of short wave length, where Maruo's formula shows good agreement with our experiments.
  • 久住 昇三, 土屋 好寛, 金井 誠, 梶谷 尚
    原稿種別: 本文
    p. 75-82
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Blockage effects due to the restriction of the tank size of the rectangular section are studied expermentally and analytically. Double model flows (DMF) around Wigley and Wigley-type models are numerically analyzed with or without tank boundaries. Two analysis methods, mirror image method and "Box" type boundary source method are introduced. Through these analyses the next 3 remarks are given; 1. The experimental resistance increase due to the blockage seems to be much more than the estimate by the restricted DMF. 2. In a medium or high Fn range, increase of wave resistance due to the blockage is significant. 3. Mean sinkage increases remarkably with increasing blockage effect.
  • 石田 駿一
    原稿種別: 本文
    p. 83-91
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The wake measurements and the propulsion tests of a model ship are carried out to study the influence of the hull on the propeller slipstream and the effect of the rudder on the propulsive performance. The experiments and the theoretical considerations, show the following results: (1) The rotational flow behind the propeller in the hull wake is similar to the flow behind the propeller operating in the open water with the same advance speed and number of revolutions. The interaction between the hull and the propeller, however, makes the axial flow distribution in the hull wake different from in the open water condition. (2) The amount of the rotational energy in the propeller slipstream behind the hull and the propeller agrees relatively well with the amount in the open water condition. (3) The delivered horse power of the hull with the rudder is less than without the rudder. The decrease of the power agrees generally well with the difference between the decrease of the kinetic energy in the propeller slipstream and the increase of the energy dissipation generating mainly in the boundary layer on the rudder.
  • 山崎 隆介
    原稿種別: 本文
    p. 93-119
    発行日: 1986/08/25
    公開日: 2018/02/25
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    An ordinary displacement type ship, which is composed of three parts, i.e., a hull, a propeller and a rudder in order from the front, is usually advanced with an almost constant speed in a seaway disturbed by waves and winds. Then the ship continues surge, sway, heave, roll, pitch and yaw motions, and is requested at first to be safe from the standpoints of motion and strength, and next to have a main engine on board, whose output is sufficient to maintain a given speed in waves and winds. In this paper, we develop the hydrodynamical method to estimate the required main engine power of a ship with a given speed in given regular waves.
  • 上入佐 光
    原稿種別: 本文
    p. 121-127
    発行日: 1986/08/25
    公開日: 2018/02/25
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    For the cavitation tests, it is important to reproduce the ship wake distribution of the propeller disk plane as accurately as possible in the cavitation tunnel. When simulating the wake distribution of a ship, two kinds of methods are commonly used; one is the wire mesh screen method which utilizes the speed difference corresponding to the density of its mesh and the other is a dummy model, or the scale model method. The former method is often adopted for the cavitation test, because of the ease of its practical operation in the cavitation tunnel, and the limitation on the size of the cavitation tunnel itself. But, it is troublesome to make the wire mesh screen, because it has been constructed by outdated technology with unreliable results. In order to make the wire mesh screen more efficient, a small wind tunnel having the same profile as the measuring section of the cavitation tunnel has been recently developed, because the ease of the measurement in the wind tunnel. First, this paper introduces the small wind tunnel that has been recently developed, and shows that its performance is sufficient for the wake measurements and is very useful for doing the wake simulation. Second, when measuring the wake distribution of a typical wire mesh screen in both the wind tunnel (in air) and the cavitation tunnel (in water), the results showed that the measurement in both tunnels agreed with each other. Third, the process of the wake simulation on the ship is minutely explained, and it is shown that a center panel is available for the wake simulation on the ships of the V type, and on the ships of the U type, a vortex generator is recommended to adopt for the correct reproduction of the high wake zone. Finally, it was shown that by using the small wind tunnel, the wake simulation could be carried out easily and efficiently, and the final results of the simulation in the wind tunnel agreed with the results measured in the cavitation tunnel.
  • 中武 一明, 小田 耕吉, 片岡 克己, 西本 仁, 安東 潤
    原稿種別: 本文
    p. 129-139
    発行日: 1986/08/25
    公開日: 2018/02/25
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    In this paper we deal with the free surface effect on the hull-propeller-rudder interactions. By using the model ship hull N-S. 1(L=2.55 m), the propeller MP-1 and the rudder model MR-4, several experiments are performed. They are the resistance test of the hull, the propeller open test, the self-propulsion test and the rudder resistance measurement at the self-propelled and the open water conditions. On the other hand, we attempt to elucidate the mechanism of the free surface effect on the hull-propeller-rudder interactions by using the source-represented hull, the simple sink propeller and the rudder model. The sink propeller model is generalized so as to represent the accelerated flow and the rotating flow in the propeller race. The rudder is represented by the source and the vortex which are distributed in the rudder center plane. Calculations are performed taking into account the wave effects for the combination of the hull, the propeller and the rudder used in the experiments. Following results are obtained. 1) The thrust deduction and the effective wake fractions and the rudder resistance vary with Froude number. 2) The presence of the rudder increases the effective wake fraction compared with the value in the hull-propeller interactions. 3) The humps and hollows of the rudder resistance correspond to those of the hull resistance.
  • 浜崎 準一, 坂後 幸広, 伊藤 政光, 山崎 正三郎, 玉島 正裕, 小倉 理一
    原稿種別: 本文
    p. 141-150
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Effects of propeller diameters, propeller skew angles and propeller longitudinal positions on self-propulsion factors of a full ship are investigated experimentally and theoretically. Five four-bladed model propellers varying diameters and skew angles were installed on a model full ship, and self-propulsion tests were carried out in the towing tank. The test results varying propeller diameters showed that according to the increase in the diameter wake fraction factor (1-w_T) values increased and values of thrust deduction factor (1-t) and relative rotative efficiency (η_R) were nealy constant. The increse in the skew angle results decrease in 1-W_T and η_R values. The significant effects were seen in the test results varying propeller longitudinal positions. Both 1-w_T, 1-t and η_R values became higher according to the propeller position approached to the rudder, above all variations of 1-t values were superior to the others. Then the increse in the propulsion efficiency became about 3-4%. Test results indicate more attention should be payed not only to the determination of diameter but also to the selection of propeller skew and its longitudinal position. The theoretical calculations based on the ship propulsion theory were performed in order to clarify the interaction mechanics between the propeller and the hull. The effects of diameters and longitudinal positions can be explained well by Yamazaki-Nakatake's theory and skew effects are also clarified by modified Ikehata's theory. It can be concluded that the ship propulsion theory, although it is still under development, now becomes an useful tool of the ship hydrodynamical design.
  • 佐々木 紀幸, 高井 通雄, 伊藤 暢基
    原稿種別: 本文
    p. 151-163
    発行日: 1986/08/25
    公開日: 2018/02/25
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    It is generally recognized that the short way of constructing the ship at small expence is to design the ship which has large block coeffcient and small ship length. Meanwhile, increase of hull fullness by this way sometimes causes unstable flow fields around the stern, which is so-called "unstable phenomena", during the self-propulsion test at a towing tank, and deteriorates propulsive efficiency. Practical solution for this matter is to equip suitable appendages in order to improve flow fields. Hitherto a stern fin in front of a propeller was treated as a regulator of flow fields around the stern on the view point of propeller exciting forces. Recent our research works reveal that a fin reduces viscous resistance of the ship and improves propulsive efficiency strongly. This paper describes hydrodynamic characteristics of a fin which locates in front of a working propeller.
  • 中村 直人
    原稿種別: 本文
    p. 165-175
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The numerical method to estimate propeller open-water characteristics based on Quasi-Continuous Method was applied to unconventional propellers such as controllable pitch propeller, tandem propellers and contra-rotating propellers. Some numerical results for these different types of propellers showed good agreement with the experiments and it was shown that Quasi-Continuous Method is useful also for the estimation of open-water characteristics of these three different types of propellers.
  • 慎 燦益, 大竹 弘一, 川上 治男
    原稿種別: 本文
    p. 177-186
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The experiments on the motions for two shallow draft ships have been carried out in regural waves. The results of experiments show that the rolling motion for shallow draft ships change by position of center of gravity of load on deck. In this paper, making use of the Strip Method, the motion characteristics of the shallow draft ship were calculated by computer and personal-computer. Authors proposed simple calculation method of the motion for the shallow draft ship. The results of calculation by the Strip Method and the simple Method were in good agreement with experimental values.
  • 大川 豊
    原稿種別: 本文
    p. 187-195
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Hydrodynamic forces on submerged rectangular cylinders oscillating relatively near a free surface were measured. Added mass coefficients and radiation waves measured simultaneously were in good agreement with the linear theory. When cylinders became close to a free surface, drag coefficients obtained from viscous damping component strongly depended on frequency unlike the case in infinite waters. The analysis of higher order terms of Fourier components of forces showed that there existed some mechanisms which were not explained by Morison type formula.
  • 野中 晃二, 不破 健, 二村 正
    原稿種別: 本文
    p. 197-212
    発行日: 1986/08/25
    公開日: 2018/02/25
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    In the previous report, measured results of wake flow and surface pressure distribution on a simple and fine hull form were presented with some theoretical investigations. In order to confirm and extend the knowledge obtained about the nature and structure of the wake flow and its relation to the hydrodynamic forces on the ship model in oblique towing condition, similar experiments were conducted on a full and practical ship model. It was a tanker model with bluff and bulbous bow, wide beam and long parallel middle body. The following five different kinds of experiments were carried out, when the model was towing with constant drift angle and constant forward speed. (1) measurement of lateral force and yaw moment acting on the model (2) measurement of pressure distribution on the hull (3) observation of surface streamlines and trailing vortices by means of dye tracer method (4) measurement of velocity and vorticity in the wake flow by means of 5-hole pitot tube and rotor-type vortexmeters (5) visualization of limiting streamlines on the hull by meams of oil film method Though the oil film method was applied on a small model (L=0.8m) in a circular water channel, the others were carried out with a large model (L=4m) in towing tanks. After the examination of these experimental results, they were compared with those for the simple and fine hull form reported in the previous paper. They were also compared with the results of potential flow calculation. Through these experimental and theoretical investigations on the wake flow around the full tanker model and the hydrodynamic forces and moment on it, the followings were obtained. (1) There observed three or four groups of trailing vortices in the wake flow. They are the main causes of hydrodynamic forces acting on a ship in manoeuvring motion. The first vortex initiates at bilge part near shoulder of the model (S.S. 8) in the leeward side. It collects the vorticity of the separated flow at the bilge in the parallel middle body, and it concentrates in a small region. On the other hand other group of vortices initiate in the aft body, which have comparable amount of vorticty in the total as the first one, spread in wider range and rotate slowly. (2) Measured pressure distribution corresponds well to the potential flow calculation in the fore body. Longitudinal distribution of lateral force obtained by surface pressure integration brings useful information about the contribution of each flow component on the lateral force and yaw moment. In the fore body, potential component is dominant, and the vortex flow component which is defined as the difference between measured total value and potential flow component, is dominant in the middle body. In the aft body, both of the components have almost the same contributions for the lateral force and yaw moment. (3) Non-linear characteristics of total lateral force to the variation of drift angle mostly comes from the difference in the lateral force distribution in the middle part, which is related to the growth of trailing vortex from shoulder part of the model. (4) Behaviour of stern vortex influences on the directional stability of the model, because linear part of lateral force is caused by the stern vortex. It is presumed by the investigation of the strength change for the stern vortex to the drift angle variation and its contribution on the lateral force distribution in the aft body. (5) Comparision between the results of full and fine ship models shows that the difference in the proportion of the potential flow component to the vortex flow component is quite important to explain the difference in the nature of hydrodynamic forces and flow structure around model. Finaly it was proved that precise flow measurement is useful not only to understand the structure of the wake but also to explain the nature and characteristics of the hydrodynamic forces on the model in manoeuvring motion.
  • 高橋 雄, 有永 真司, 石井 哲郎
    原稿種別: 本文
    p. 213-226
    発行日: 1986/08/25
    公開日: 2018/02/25
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    As a high-speed passenger ship, a new concept "Hi-Stable Cabin Craft" is introduced and its technical feasibility was investigated. The "Hi-Stable Cabin" implies highly motion-stabilized cabin, which is mechanically supported by the main ship hull by means of a hydraulic supporting system, with which ship's vertical motion is automatically controlled so as to be suppressed into zero. Therefore, acceleration in the cabin is well minimized so that the passengers will enjoy a trip even in a rough seaway. Computer simulation was carried out regarding the motion control of the Hi-Stable Cabin Craft in waves, and it was confirmed that high degree of stabilization was possible. Model experiment was carried out by use of 3.8 meter-long ship model of the Hi-Stable Cabin Craft equiped with a electroservo mechasism supporting system. Measured pitching motion of the cabin was less than 1/8 of that of the main hull, and remarkable reduction of motion of the cabin was attained. Technical feasibility in practical design of the Hi-Stable Cabin Craft was studied from various aspect such as, general arrangement, hydraulic system, cabin structure, stability, economy of operation, etc. compared with a conventional high-speed craft. As a result, it was considered that the Hi-Stable Cabin Craft appeared to be one of the promissing concept of the advanced marine vehicle for the future.
  • 小寺山 亘, 中村 昌彦, 大楠 丹
    原稿種別: 本文
    p. 227-240
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Effects of hydrodynamic forces acting on the cold water pipe and mooring lines on motions of the OTEC platform are investigated experimentally and theoretically. Hydrodynamic forces acting on the cold water pipe and mooring chains oscillating in a water are obtained by using mode methods. The computer time needed for the calculations are very short, so these methods proposed in this paper are of much practical use. Calculated results of the bending moment and shearing force of the cold water pipe at its upper end, the horizontal and vertical components of the dynamic tension of the mooring chain at the mooring point are compared with those of experiments. They are in good agreements. Wave exciting forces and hydrodynamic forces acting on the platform are obtained with the surface integral equation method. The results of calculations are compared with those of forced-surging tests and wave force measurements. The calculated results coinside with experimens. Experiments and theoretical calculations on the motions of the moored OTEC platform show that the viscous drag forces acting on the cold water pipe and mooring chains have a great effect on the pitching motion at its resonant period. They act as the viscous damping forces for the motion of the platform at its resonant period, and reduce its magnification factor. We could not confirm this fact experimentally in the cases of heaving and surging motion, because resonant periods of these motions are very long and beyond the ability of our experimental facilities, but the applicability of the calculation method is well confirmed by the experiments on the pitching motion. The heaving and surging motion at their resonant periods can be estimated with enough accuracy by using the calculation method proposed in this report.
  • 真鍋 大覚
    原稿種別: 本文
    p. 241-256
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Before 2^h35^m-3^h18^m earthquake and tidal wave arize the energy of solar radiation suddenly diminishes. There are special undulations with the velocity of 1.149-1.406km/sec which are detected in the records of marinograph and seismograph. These speeds are the same value of sonic wave in the atomosphere, ionosphere and ocean. Though the fundamental equation concerning to seismological and atomospheric wave is different. The solutions are expressed in the form of common type of Bessel function. Elastical and Hydraulical analogy exist mathematicaly. There are number of succesive series of progressive and stational wave system which are combined with each other by the relation of tanhkh=-tankh, where h is the depth of ocean or altitude of layer, and 2π/k is wave length. Travel curve for oceanic and seismological wave should be prepared for the purpose of classification and systematization.
  • 橋本 恒雄
    原稿種別: 本文
    p. 257-272
    発行日: 1986/08/25
    公開日: 2018/02/25
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    As well known, steel merchant ships are restricted its hull girder deflection as 1/1,000 of length by the regurations of the Clasification Society of Shippings. For example, large aluminume ship's hull girder deflections are limited as 1.7 times of steel hull by Americal Bureau of Shipping, and 1.5 times of high tension steel destroyer hull by U.S. Navy. Author have introduced the design formulars of hull girder moment of inertia values for large F.R.P. and Wooden Minesweepers, and its deflection limit line well resembled to the plotted points of actual ship's hull girders. On the case of hull structure design, at first set the shell plate thickness by several formulars, and by of which calcurate the required moment of inertia values, then reinforce the hull girder structure of 0.4L midship if necessary. By this way, we may be able to dissipate the damage of hull structurs from sevelal unexpected coupled streses.
  • 金子 幸雄, 高橋 雄, 木原 和之
    原稿種別: 本文
    p. 273-282
    発行日: 1986/08/25
    公開日: 2018/02/25
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    A simple formula for estimating wave bending moment on large semidisplacement high-speed craft was derived from their motion in waves calculated by modified strip method including non-linear effect and slamming load in consideration of actual sea condition. The similar formula was made for shearing force. The design loads (equivalent uniformly distributed load) for bottom structure due to slamming were proposed based on resonance condition of ships motion in waves. The author would like to suggest reasonable extension of the Japanese Tentative Rules to large high speed boats over 24m long.
  • 永井 保, Tsuneo HASHIMOTO
    原稿種別: 本文
    p. 283-292
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Design manual of laminates is proposed for marine use: such as a case to determine the thickness of flat bottom shell plating panel of FRP boats, based on the previous papers already published concerning dynamical design method. First, how to calculate the thickness is explained by our empirical formulae, then the requirement to sustain enough strength against dynamic wave loadings is examined from the viewpoint of both allowable stress safety factor and deflection coefficient value. Several examples are displayed for actual use. Finally, the comparison with other classification rules is given, showing good reasonable results. Proposed method is, therefore, verified applicable to determine the thickness of laminate bottom shell plates.
  • 木原 和之, 石井 哲郎
    原稿種別: 本文
    p. 293-300
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The effect of deadrise angle β on the performance of high speed craft is discussed. Tank tests were carried out by use of series models with three (3) different deadrise angle in order to investigate the effect of them on the vertical acceleration of the craft both in regular and irregular waves, and the resistance of hull in smooth water. Measured acceleration was compared with calculated one by non-linear strip theory. The results are summarized as follows; (1) To improve the seaworthiness of high speed craft which cruise in rough water, larger deadrise angle has the advantage in vertical acceleration compared with conventional deadrise, about 20°. (2) The conventional deadrise angle, about 20°, has the most appropriate capability in resistance of high speed craft in the range of Froude number over 0.8. (3) Computer simulation program based on non-linear strip theory is very useful to evaluate seakeeping qualities for preliminary design of high speed craft.
  • 新開 明二, 鳥越 彰, 井関 俊夫, 岩本 才次
    原稿種別: 本文
    p. 301-310
    発行日: 1986/08/25
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    A method is proposed for calculations of the statistical distribution of the maxima of nonlinear ship response such as the hydrodynamic pressure induced on the full-filled prismatic tank walls. The application of this method is made for a large oil tanker in short-term sea waves. The calculated results of the statistical distribution of the maxima of the non-linear hydrodynamic pressure have been examined in comparison with histograms obtained from the numerical simulated histories of the non-linear one. Satisfactory agreement is found between both results and the validity of the proposed method is recognized. And, the short-term correlation coefficients between component ship accelerations are investigated to examine the utility of the proposed method.
  • 古林 義弘
    原稿種別: 本文
    p. 311-317
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Prior to docking for the inspection cargo tanks of LNG carrier should be warmed up to the normal temperature. This operations are performed by supplying the hot vapor heated by the steam heaters and transferred by the gas compressors installed on board ship to the cargo tank bottom through the closed loop piping for the safety against an explosive gas of LNG. Before starting the warming up, small amount of LNG residue is left at the bottom of tanks, therefore hot vapor is supplied to the bottom to expedite the vaporization of LNG residue at an early stage of operation. Mixture of hot and vaporized gas rises up toward the tank top transferring the heat to the cold vapor and tank wall according to the thermal transfer rule. In order to maintain the maximum tank pressure under a certain level in closed loop system, increment of vapor volume with temperature and time should be discharged to the atmosphere through the control valve by sensing the tank pressure according to the gas rule. In this paper equations of thermal equilibrium and mass balance are established for each part of tank and vapor divided vertically into three portions and solved as the initial value problem by means of Picard method.In this analyses author introduced two kinds of thermal efficiency, mixing efficiency of hot and cold vapor η and enthalpy contribution efficiency ε. On the other hand surface heat transfer coefficient at the tank wall and liquid surface being an important factor for the evaluation of heat transfer from hot vapor, Merk prins' equation of natural convection for tank wall and Colburn's equation of forced convection of turbulent flow for the surface of LNG residue were used respectively.
  • 青木 楠雄
    原稿種別: 本文
    p. 319-326
    発行日: 1986/08/25
    公開日: 2018/02/25
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    An evaluation of the evaporation rate of crude oil on voyage is one of the most important factor in designing the tank venting system of the crude oil tankers. The author gave some theoretical considerations on evaluation of the evaporation rate of crude oil: one is the macroscopic evaluation from the viewpoint of the energy conversion method and the other is the microscopic evaluatioon from the viewpoint of the transfer phenomena method. The results obtained from these theories agree well with the experimental results.
  • 矢島 浩, 多田 益男, 山形 俊介, 出口 明雄, 今井 純一郎, 勝田 順一
    原稿種別: 本文
    p. 327-333
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The authors performed some studies on the results of surface-notched double tension tests which were carried out on 50kgf/mm^2-class high-tensile ship hull steel, carbon steel for low-temperature pressure vessels of JIS specification, and 9% Ni steel, with the following results. (1) Arresting the brittle crack propagation upon reaching about 0.5 to 0.7W (W: specimen width) in the temperature-gradient surface-notched double tension test produced the same crack propagation-arrest characteristics as in the temperature-gradient double tension test hitherto carried out without the surface notch. (2) The surface-notched double tension test was found to be highly effective in evaluating the brittle crack propagation-arrest characteristics of high-toughness steels like 9% Ni steel.
  • 矢島 浩, 多田 益男, 梶本 勝也, 縄田 卓生, 野田 俊介
    原稿種別: 本文
    p. 335-343
    発行日: 1986/08/25
    公開日: 2018/02/25
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    The paper reviews the results of a series of tests the authors performed on base metal and high-heat-input welded joints of TMCP-manufactured low-temperature high-tensile steels 36 and 42(43)kgf/mm^2 classes in yield point to evaluate their strength characteristics for application to ocean structures to be used in frigid sea areas. The evaluation concerned in particular the following. (1) Toughness required for use as ocean structural steels. (2) Applicability of the TMCP steels to ocean structures used in frigid sea as viewed from (1) above. (3) Advantages of the TMCP steels as ocean structural material from view points of weldability and workability.
  • 勝田 順一, 中島 正樹, 前田 穂積, 矢島 浩
    原稿種別: 本文
    p. 345-356
    発行日: 1986/08/25
    公開日: 2018/02/25
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    Our previous paper made it clear that the fatigue strength was influenced by the angle between progressing direction of fatigue crack and ferrite-pearlite layer and the fatigue life tend to increase with the separation index. Furthermore, this paper deals with the fatigue crack propagation on the specimen with surface notch and the specimen with through thickness notch at room and sub-zero temperature, and shows the anisotropic effect of thickness direction in the TMCP steel plate with tendency to occur the separation. The results obtained are summarized as follows; (1) In the case of surface fatigue crack, the rate of fatigue crack propagation has a tendency to decrease with the separation index (2) The propagation of surface fatigue crack is obstructed by micro-separations in TMCP steel plate with tendency to occur the separation. (3) The effect of the separation on the rate of fatigue crack propagation in the direction of plate width is not recognized.
  • 原稿種別: 付録等
    p. 357-362
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 目次
    p. Toc1-
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 目次
    p. Toc2-
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 表紙
    p. Cover3-
    発行日: 1986/08/25
    公開日: 2018/02/25
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  • 原稿種別: 表紙
    p. Cover4-
    発行日: 1986/08/25
    公開日: 2018/02/25
    会議録・要旨集 フリー
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