著者

恵美 洋彦 湯浅 通史 熊野 厚 山本 規雄 有馬 俊朗 海野 昌俊

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1993, no.174, pp.735-744, 1993 (Released:2009-09-04)

参考文献数

7

被引用文献数

9 9

---

Protections of corrosion in main hull structures and offshore structures have a great influence on their life. The authors have studied on protective means of the corrosions with investigation of actual conditions of aging effects to coatings in water ballast tanks for 22 ships aged 4 to 20 years.In the report, is described, i) a tendency of secular deterioration of the coatings, ii) primary factor of infulence to the deterioration, iii) forecast method of the coating conditions with aging effects, and iv) a proposal of the best specification and a maintenance for a long life service of ships.

著者

林 昌奎 小林 豪毅 山西 一臣 鈴木 文博

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.2003, no.194, pp.241-246, 2003 (Released:2007-05-30)

参考文献数

8

被引用文献数

2

---

Microwave remote sensing is effective technique for sea surface measurement. For example, it enables us to know the wind vector on global scale. In order to develop more advanced measurement, it is necessary to understand the mechanism of microwave scattering at sea surface. This phenomenon consists of two physical processes. One is the formation of sea surface by the composite action of wind, waves and currents, and the other is microwave scattering at that surface. Because these processes are so complicated, appropriate models are not established. In this paper, the relation between sea surface condition and microwave scattering is investigated. Microwave scattering from wind wave surfaces is measured in the experimental tank and the results are analyzed by scattering coefficients and Doppler spectra. In order to connect these values with water surface parameters, surface condition is investigated minutely. The energy of high frequency waves is expressed by the friction velocity, and so it is presumed that there is the universal law between friction velocity and scattering coefficient. Since wind-generated current exist, the usual dispersion relation is not available. Furthermore, very high frequency components move at the phase velocity of components near the spectral peak. The results of Doppler spectra agree with that phenomenon.

著者

川島 敏彦 芳村 康男 鈴木 四郎 大本 耕司

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.2003, no.193, pp.1-9, 2003 (Released:2007-05-30)

参考文献数

7

被引用文献数

3

---

Fishing boats have several restrictions on their machinery arrangements and space utility on deck. For the improvement of the stability and the deck utility, the fitting of a bulge on sidewall of the vessel is one of the solutions. However, the bulge generally makes a significant increase of hull resistance and loss of speed.At the principal design stage of the elongation of the fisheries research ship“Ushio-maru”, the University of Hokkaido, the authors examined the suitable form of the bulge to improve the stability without increase of the hull resistance. For this purpose, systematic calculations of wave making resistance by Rankine's source method and model experiments using a circulating water channel have been conducted. In this process, it has been found that the optimized bulge form can decrease the hull resistance.In this paper, the authors discuss about the mechanism of the hull resistance decrease by a bulge based on the view point of flow field around hull and propose the suitable method to design the bulge form. Thistechnique has been applied to the actual elongation design of“Ushio-maru”, and then it has been confirmed by the experimental model tests as well as the full scale trials.

著者

藤田 譲 堀 徹 井上 清 村田 修二 摩嶋 禎規

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1989, no.165, pp.215-224, 1989 (Released:2009-09-16)

参考文献数

9

---

Wooden ships up to around 55 m in length have been so far designed and built with hulls of double skin planking which consists of each single layer of longitudinal planking and diagonal planking crossing with an angle of 45°. Based on successful operation of these ships, large-scaled wooden ships of around 70 m are recently under consideration adopting hulls of triple skin planking. The triple skin planking consists of the outer skin of a single layer of longitudinal planking and the inner skin of double layers of diagonal planking wihch cross the longitudinal planks with angles (θ) of ±45°.Experiments and theoretical investigation as listed in the followings have been made in order to establish design formulae for the longitudinal bending and shear strength of hulls of the triple skin planking : (1) Simplified formulae are induced for calculating the rigidities and the stresses of the triple skin planking, and the practical methods are shown on the longitudinal and shear strength of hulls.(2) The results of the structural loading tests of the box-shaped ship model sizing 6.54 × 0.9 × 1.04 m are compared with the structural analyses by the three-dimensional (3D) truss model. The structural members of the test model are in 1/2 scale of those of a prototype ship except the overall dimensions.(3) The results of the same kind of 3D truss analyses made for the whole hull of the prototype ship are compared with the calculations by simplified formulae.It is concluded as follows : ·The 3D truss model reasonably represents the behaviour of the triple skin planking.The simplified calculation methods can be applied to actual ship design.·The effectiveness of the diagonal planking on the longitudinal bending strenth is 25 % theoretically when θ= ±45°, and a practical value of 20 % is proposed.·The inner skin of two layers of diagonal planking predominantly carries shear forces. The axial stresses of diagonal planks are simply obtained by doubling the shear stresses when θ= ±45°.·Longitudinal members such as gunwale, chine and keel contribute to the shear strength of a hull by their sectional areas multiplied by a factor of 4G/E theoretically when the rotations of the sections are restrained by neighbouring members. The actual degree of contribution is subject to further investigation.

著者

鈴木,規之

出版者

日本造船学会

雑誌

日本造船学会論文集

巻号頁・発行日

no.162, 1987-12

---

In this paper the extended penalty function approach to dynamic contact problems recently proposed by Asano is further discussed. The equation of motion, in which velocities as well as displacements are constrained by the physical consideration, coincides with the one based on the virtual work principle given by Asano. The optimal penalty numbers in this approach are discussed by using a simple two-element model. The obtained results are applied to the finite element analysis of contact-impact problem of two elastic rods and the validity of the present method is confirmed through the comparison of the numerical results with the exact solution based on the one-dimensional wave propagation theory. The present method is also applied to the friction-excited vibration of a two-dimensional elastic block on a sliding belt, and it is shown that the kinematic coefficient of friction can be lower than the static one in the camplete system even when they are assumed to be equal to each other on the interface between the block and the belt.

著者

村重 淳 木下 健

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1990, no.168, pp.183-192, 1990 (Released:2009-09-16)

参考文献数

12

被引用文献数

1 2

---

Wave focusing has been attracting ocean engineers as one of the most promising techniques to control ocean waves. It creates a calm sea area and helps efficient utilization of wave energy. In the present work, a hydrodynamic singularity distribution which expresses a wave focusing lens is derived by the method of matched asymptotic expansion, assuming slenderness of the lens and high frequency of incident waves. The singularity distribution gives the following necessary conditions for scattered waves in each section of the lens : there is no reflection from the lens and the transmitted waves suffer a phase shift in passing the lens. The phase shift is given by the wavenumber and the distance between the section and the focus. From these conditions, we examine a sectional shape of the lens and determine the whole geometry.It is shown by experiments and numerical computations using the two dimensional doublet distribution method that a submerged chevron shape plate, which is suitably folded, scatters a wave system which satisfies the above conditions at a certain wave frequency, but not in wide band of wave frequencies because of dispersion of water waves.Then it is shown by experiments that a certain number of submerged circular cylinders, which are horizontally arranged at intervals just like a raft, transmits waves which have enough phase shift to focus waves but reflects almost no waves in wide band of wave frequencies.Finally, we examine performances of three types of lens, namely, submerged flat plate, submerged chevron shape plate, and submerged circular cylinders, in both regular and irregular waves. It is shown by numerical computations that the wave focusing efficiency of the lens consisting of circular cylinders is about twice that of the flat plate type lens and that the drift force acting on the former is less than half of that on the latter in irregular waves.

著者

川中 幸一 馬場 信弘

出版者

社団法人 日本船舶海洋工学会

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.178, pp.33-40, 1995-12

参考文献数

10

被引用文献数

10 2

---

Computational results of a two-dimensional gravity current in a lock-exchange flow is presented in which a finite volume of homogeneous fluid was released instantaneously into another fluid of slightly lower density when a lock gate was opened. The computations were performed in a two-dimensional channel by solving the incompressible Navier-Stokes equation for an inhomogeneous fluid, the continuity equation and the transport equation for solute by the finite volume method. For accurate representation of small density difference, the density variation relative to the characteristic density difference was used as one of primitive variables. The finite volume formulation holds the conservative property with respect to mass at the boundaries as well as at the density interface so that the total mass of the two fluids with different density remains constant. Some of standard numerical schemes were used to examine their performance to the density jump of the interface. The computed gravity current moves steadily in an initial phase, and the front speed decreases with distance in a self-similar phase when an internal bore on the interface reflected from the back of the lock reaches the front of the current. The effects of the bottom boundary layer on the internal structure of the current is investigated from numerical experiments with no slip and free-slip boundary conditions. The volume of the diluted fluid in a gravity current by the entrainment of ambient fluid is evaluated as a function of time to quantify the mixing. The result indicates that at low Reynolds numbers the subsequent mixing occurs in the early stage of the evolution of the gravity current in a lock-exchange flow.

著者

片岡 秀太郎 宮田 秀明 金井 亮浩

出版者

社団法人 日本船舶海洋工学会

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.182, pp.113-120, 1997-12

参考文献数

9

被引用文献数

3

---

A new technique for PPS (performance prediction simulation) to design sailing boats is developed. The performance of a sailing boat with 6 degrees of freedom is predicted. The boat sails in the simulation with automatic steering to get steady state and with automatic sail trimming to get better VMG (Velocity Made Good). With this technique the steady performance of sailing boats is predicted with sufficient accuracy on various conditions. This system is applied to the design procedure for a IACC (International America's Cup Class) sailing boat for which the steady sailing attitude plays an important role for the sailing performance.

著者

山本 善之 角 洋一 鈴木 和夫 鈴木 政直 鈴木 隆男

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1985, no.158, pp.291-300, 1985 (Released:2009-09-04)

参考文献数

16

被引用文献数

1 1

---

In 1935 the Forth Fleet of the Imperial Navy encountered a typhoon in the occasion of the naval grand maneuvers in the Pacific Ocean off the northern coast of Honshu Island of Japan, and many naval vessels of the fleet were damaged. Destroyers “HATSUYUKI” and “YUGIRI” lost their fore bodies being splitted in front of bridges with 51 crews on board. They were designed on the basis of the theories and experiments of those days ; they had long forecastles with large flare for high performance in rough seas, and their section moduli were designed to be in proportion to the estimated longitudinal bending moment for the reduction of hull weight.In this paper the authors attempt to analyze the disaster of the two destroyers theoretically with the aid of the knowledge available today. The wave bending moments acting on the destroyers are calculated for several wave conditions by TSLAM based on the nonlinear theory of ship motions, and they are compared with the ultimate moment. It is shown from the calculated results that the sagging moments are increased by slamming to the flare and buoyancy of the long forecastle dipped into a wave. If the longitudinal strength were designed in such a manner that the section modulus had an almost constant value sufficiently far towards the fore body of the vessel, the disaster of the two destroyers could have been avoided.

著者

中井 裕司 田畑 光敏

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1990, no.168, pp.623-628, 1990

被引用文献数

3

---

SHIP & OCEAN FOUNDATION studies on Pilot Model for CIM in shipbulding. One of the subjects in this project, we researched on modeling for Piping Arrangement in Shipbuilding. This paper proposed Piping Arrangement Model based on Object Oriented and Entity-Relationship method. Following this concept, we developed Prototype System by Smalltalk80, this is object oriented program language and enviroment.<BR>The Prototype System applied to midship part of oil tanker and obtained efficiency of proposed Piping Arrangement Model.

著者

浜本 剛実

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1968, no.124, pp.1-7, 1968-12-20 (Released:2009-09-04)

参考文献数

6

被引用文献数

1

---

In this paper, the approximate analysis of the low aspect ratio wing is carried out, getting a new integral equation of the lifting surface being oblique in the plane of free stream in order to estimate the lift distribution on the wing with low aspect ratio.The bound vortices are herein assumed to be distributed over the wing surface that is considered as the lifting surface and hence the induced free vortex filaments extend over the infinite down. stream having reasonable small angle to the wing surface.Applying this integral equation to the extreme case of the lifting surface, it is shown that Munk's Integral Equation is derived in case of the infinite span, and on the other hand, in case of the infinite chord wing the same result is given as that being obtained by Newton's momentum theory. The integral equation identical with that by Prandtl is further derived from the author's equation, putting aspect ratio high as the approximate treatment.

著者

遠山 泰美 小野 志郎 西原 誠一郎

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1992, no.172, pp.383-391, 1992 (Released:2009-09-04)

参考文献数

4

被引用文献数

1

---

The first commercial ACV service started with Vickers VA-3 in Britain in 1962. Since 1964 Mitsui (MES) has been making R and D efforts in ACV production and constructed 29 hovercraft of MV-PP series.Recent MV-PP10, a diesel powered 105 passenger hovercraft has achieved high performance and remarkable running cost efficiency. The weight penalty due to the adoption of diesel engines and welded aluminium structures resulted in water drag increase particularly in low speed region. In order to overcome the water scoop, model tests and FEM numerical analyses together with full scale sea trials have been conducted. Full scale measurements with conventional rear skirt systems revealed that the rear skirts would scoop the sea water at about 8 knots.Through the research and development works new rear skirts were conceived and designed for actual use considering geometric instability of the inflated membrane. There were great improvements in the reduction of the drag compared with the conventional systems.Two MV-PP10 hovercraft equipped with the improved rear skirts are now in commercial service for access to Oita airport by Oita Hoverferry Co, Ltd.

著者

吉野 亥三郎 森谷 周行 八木 光 山下 進

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1993, no.174, pp.365-375, 1993 (Released:2009-09-04)

参考文献数

16

---

Focussing on the sea-going maneuverability of a 105-passenger hovercraft, the authors made investigations through series of model tests and computer simulations. The wind forces acting on a scale model, which represents superstructure and cushion form, were measured in a wind tunnel test. Oblique towing tests with self-lifting model were carried out for the hydrodynamic characteristics between cushion skirt and water plane. Regarding the characteristics of control surfaces, the force measurement tests with ducted propeller and rudder in wind tunnel were carried out. Based on these results of model tests, the authors developed a simulation program which employs proper mathematical models for each force components, namely cushion skirt, wind, propellers, rudders and thruster. The output of simulation showed fairly good agreement with the results of actual sea trial. Especially in the case of course keeping in beam wind, the reverse of check-helm direction around Froude number of 1.0 experienced in actual operations were confirmed through computer simulation. Lastly the results of extensive investigations on the sea-going maneuverability of the hovercraft are explained.

著者

小池 裕二 吉海 研 広重 栄基 谷田 宏次 牟田口 勝生

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1994, no.176, pp.137-143, 1994 (Released:2009-01-08)

参考文献数

3

被引用文献数

1 2

---

An actively controlled anti-rolling system has been developed with a view of reducing the rolling motion of a ship by the movement of the mass controlled by actuator. It is of hybrid type combining the pendulum-base passive type with active type driven by a relatively small electric motor. The hybrid type has merits of (a) providing almost the same damping performance as active type (depending solely on actuators for obtaining controlled movement of damper mass), while requiring only a much smaller control force for moving the damper mass, and (b) continuing to function solely on its passive mechanism in the event of power failure. This system consists of a sliding mass on the rail shaped in a circular arc, and the compact, passive pendulum mechanism is realized that does not require a suspension structure such as a simple pendulum or spring mechanism. The driving force to control the movement of the damper mass is imparted from the electric motor through reduction gearing connected to a gear and pinion mechanism. The LQ control theory has been adopted for controlling the damper mass. At-sea experiments were performed with a ship (weight approx. 190t) to verify damping effects of the hybrid anti-rolling system. The rollings were reduced to about 1/3 in beam seas under the condition that the ship was stationary. The performance was further compared between hybrid type and passive type. Hybrid type promised better damping performance by 15% than passive type. The hybrid type also attenuated rollings with a forward speed of ship to about 1/2 in following seas, in the case of which passive type presented difficulty of providing damping effects markedly. Good agreement was obtained between measurement and calculation.

著者

福地 信義 小山 清文 篠田 岳思

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1999, no.186, pp.545-558, 1999 (Released:2009-09-04)

参考文献数

13

被引用文献数

4 3

---

In the safety design of marine systems, it has to justly give a matter over human life in the case of outbreak of a marine accident such as fires and collisions. It may be difficult to establish a safe evacuation system by the cause of uncertain behavioral patterns based on human factors with ambiguity. Besides, the psychological effect on behavior of evacuee that is terrified under the stimulus by accident, should be considered in the redundancy system for safe evacuation. Accordingly, the safe evacuation system with the intention of securing evacuation routes and reducing escape time, is desirably designed by grasping the personnel behavior with psychological intelligence process in an emergency of marine accident.In this paper, the evacuation behaviors can be predicted by using the proposed walking model with individual capacity of visible length and avoidance process for obstacles. Further, the mathematical model of psychological intelligence process in an emergency is contrived herein, in which the evacuation movement is simulated in the consideration of the decrease of walking speed and the occurrence of self-isolation in psychological action according to the magnitudes of accident stimulus. By applying these models to common spaces in a dinning cruise ship, taking account of the human factors with psychological action is rather valued in the safe evacuation system and the validity of the proposed models can be confirmed.

著者

板垣 浩 豊田 政男 真島 篤 朝田 洋雄

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1981, no.149, pp.287-297, 1981 (Released:2010-01-25)

参考文献数

20

---

The role of adequate non-destructive inspections and following repairs of detected flaws is essential in order to continue the integrity of welded structures. It is, however, pointed out that catastrophic failures sometimes happen due to insufficient repairs having no regard for unfavorable effects of repair.In case of welded joints, when a detected flaw is repaired by renewed welding, the fracture toughness of a flaw which is not discovered and adjacent to the detected flaw becomes smaller because of so-called the Hot Straining Embrittlement. Therefore, if such effect mentioned above is not taken into account, the reliability of the welded joint must be overestimated.The purpose of the research is to investigate the effect of the Hot Straining Embrittlement giving rise to serious deterioration of fracture toughness and evaluate the optimum range of repair in order to prevent an unexpected failure with the aid of reliability analysis.This report, at first, describes deterministic or probabilistic factors which should be adopted in the reliability analysis, a model and formulations of the analysis, and then, presents the comparison between estimated reliabilities of various cases, i. e., no repair, repair with or without the Hot Straining Embrittlement (HSE).From the results of numerical examples, it is shown that, 1) the probability of failure of repair with HSE is extremely larger than that of repair without HSE, 2) when the detected flaw is small, the probability of failure of no repair becomes smaller than that of repair with HSE, and 3) the important results are obtained on the range of repair with HSE.

著者

岩崎 紀夫 加藤 昭彦 川原 正言

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1981, no.149, pp.268-278, 1981 (Released:2009-09-16)

参考文献数

7

被引用文献数

1

---

Fatigue crack growth under random loading has been extensively studied since nearly a decade in relation with the design of offshore structures, ship hulls, pressure vessels and so on.For the sake of simplicity, random loads in service conditions are often simulated by block programmed loads in laboratory fatigue tests. However, very few studies have been conducted on the difference of fatigue crack growth behaviour between random loads and block programmed loads.The authors previously presented an experimental study on fatigue crack growth under block programmed loads, and discussed on the effect of block size on fatigue crack growth life. A proposed model gave a good prediction of fatigue crack growth life in block programmed loading tests. In the present paper, fatigue crack growth tests were performed under three different types of block or random loads. Experimental results show that fatigue crack growth behaviour under random loads is very similar to that under block programmed loads with short periods. Miner's rule gave a non-conservative estimation for crack growth life under both random and short block loads. Life estimation by the model previously proposed agreed well to the experimental results.

著者

川口 勝義 浦 環 折出 光宏 坂巻 隆

出版者

社団法人 日本船舶海洋工学会

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.178, pp.657-666, 1995-12

参考文献数

9

被引用文献数

8 7

---

The ALBAC designed by the authors and constructed in 1992 is a prototype of shuttle type autonomous underwater vehicles. The ALBAC was developed for the oceanographic measurement of water column on the way and from the seabed.<BR>The vehicle does not have a propeller thruster but moves aside by gliding. To carry out the mission, the software includes three simple fuzzy controllers for longitudinal and lateral motion. The longitudinal motion controller displaces the longitudinal coordinate of the location of the center of gravity (C. G.) and controls the gliding angle, respectively of the vehicle. Two lateral motion controllers also displace the lateral coordinate of C. G. and control azimuth and yaw rate. The parameters of the fuzzy rules were optimized by using the Evolution Strategies on the simulator, and examined based on the motion data of every trial. 300-meter depth sea trials were successfully conducted in April of 1995 at the Suruga Bay of Japan.<BR>Consequently, the ALBAC is highly reliable and can be easily operated to carry out the mission to measure the profile of scientific data.

著者

藤田 譲 野本 敏治 仁保 治

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1978, no.144, pp.437-445, 1978 (Released:2010-01-20)

参考文献数

23

---

In the previous paper, studies on the ultimate strength of stiffened plates with initial deformations were made, and a new analytical method was proposed. In this paper, the effects of initial imperfections due to welding on the ultimate strength are investigated.It is well known that these welding-induced imperfections which inevitably occur during the manufacturing process reduce the compressive strengh of structural elements. Almost all the strength analyses that have been made so far are based on the measured or assumed initial imperfections.Firstly, in this paper, the practical method to predict welding-induced imperfections such as welding distortion and welding residual stress is introduced.Secondly, an analytical method reported in the previous paper is further developed for describing welded plate behavior in compression.Finally, making use of aboved-mentioned results, the ultimate strength of stiffened plates is discussed.The following conclusions are obtained.1) It is introduced how to predict welding-induced imperfections according to welding conditions. The authors extended their method in order to estimate the ultimate strength of welded plates with these imperfections. Since this method is an analytical one that the ultimate strength can easily be estimated comparing with other numerical methods.2) The obtained results are checked against available results from numerical analyses and experimental data. It is confirmed that this proposed method is fairly efficient one.3) The imperfections due to welding reduce compressive strength of plates. Reduction in ultimate strength is most remarkable in case of the square plate having both slenderness ratio b/t√σY/E=1.9 and small intial deformation. For slenderer plates, reduction ratio caused by welding-induced imperfections is approximately constant. For thicker plates, the effect of residual stress on the ultimate strength disappears.4) The welding residual stress in stiffened plates lowers the panel element strength so that minimum stiffeness ratios (γBmin, γUmin) of stiffened plates becomes smaller than those (γBmin, γUmin) of stress-free stiffened plates.

著者

町田 進 的場 正明 吉成 仁志 新村 豊

出版者

The Japan Society of Naval Architects and Ocean Engineers

雑誌

日本造船学会論文集 (ISSN:05148499)

巻号頁・発行日

vol.1990, no.168, pp.605-614, 1990 (Released:2009-09-16)

参考文献数

13

被引用文献数

1

---

Ship life depends on many factors. The factors will be divided into three groups, the law of nature, performance and economy. The laws of nature are mainly fatigue and corrosion which reduce the retained structural toughness in aged ships. The performance factors of social impact will sometimes act key point. For example, marine pollution has a great influence on types of ships. In economy factors, investment and its recovery are basic ones that should be analyzed, and cost sensitivity of each of the factors should be analyzed on the point of effect on life. And some investigations show low finantial merit in ship life extention. The authors investigated the factors for proper ship life in basic and fundamental aspect, and confirmed that it should be taken heads to link the factors together. The points to be cleared in engineering point of view are the properties of corroded plates, and some results show very low fatigue strength and fracture toughness that warn low strength redundancy of aged ships.