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自卸砂船是广东省珠江流域一种主要的运输船类,由于使用灵活方便,对目的地码头要求不高,因此在广东珠江流域得到广泛的应用。这类船舶具有长大纵通斗形开式砂舱。舱长较长,砂舱围板较高,货物重心较高,因此对这类船舶的稳性要求较高,而复原力臂曲线是决定自卸砂船稳性的最重要因素,科学合理的计算自卸砂船的复原臂曲线,是保证船舶稳性计 相似文献
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随着吉安经济的蓬勃发展,基础设施建设及房地产的开发对砂石需求量越来越大,辖区内自卸式砂船的数量越来越多,单船吨位越来越大,而自卸砂船稳性和结构先天不足,造成很多船毁人亡事故。文中结合辖区自卸式砂船的实际情况,从船舶的稳性、船体结构、排水设备设置、装载高度、现场监管等角度谈自卸式砂船的事故预防。 相似文献
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主要探讨自卸砂船改V型舱底为W型底,从船舶的舱底形状、舱容、货物重心、船舶总重心高、稳性以及船体纵向强度等方面作综合考虑,较好解决内河自卸砂船稳性裕度不足的问题。 相似文献
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以一艘87 m自卸砂船为研究对象,介绍破损载况组合、渗透率、风雨密点与无保护开口、破舱稳性计算衡准。根据《船舶与海上设施法定检验规则-国内航行海船法定检验技术规则》2011,采用CCS船级社软件COMPASS对自卸砂船的概率破舱稳性进行建模,计算表明,该船的概率破舱稳性满足法规要求。 相似文献
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近几年来,多条装运红土镍矿的船舶在南中国海倾覆沉没,引起业界的震惊。红土镍矿是一种非常特殊的矿物质,在运输过程中,如果船舶遭遇风浪,或船舶本身长时间的振动,都会导致该矿石的表面液化。液化后的混合液体具有较强粘性,可以形成自由液面。但由于现存的用于计算船舶自由液面的方法不适合于具有较大粘性的液体,因而无法解释运输该种货物船舶倾覆沉没的原因。所以,该文采用数学建模的方法,对运输红土镍矿的船舶进行了模拟计算。得出的结论是当流体的惯性力大于流体的粘性剪力时,粘性流体对船舶的作用力矩随时间的变化总趋势是逐渐增大。当流体产生的横向惯性力远大于流体的剪切阻力时,流体将会挣脱剪切阻力的束缚,迅速滑向船舶的一侧,使船舶的横稳性迅速消失,最终导致船舶很快倾覆沉没。 相似文献
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Naoya Umeda Akihiko Matsuda Masami Hamamoto Shiro Suzuki 《Journal of Marine Science and Technology》1999,4(2):45-57
A systematic method for assessing intact ship stability with a free-running model in a seakeeping and maneuvering basin is
proposed in this paper. Model experiments were carried out in extremely steep regular waves for a model drifting, running
in head seas, and quartering seas. This method was applied to two purse seiners, and efficiently identified thresholds in
metacentric heights for capsizing of these ships. These capsizing thresholds are compared with requirements of the IMO Code
on Intact Stability. This series of model experiments also confirms that capsizing at the threshold occurs only in quartering
seas, and shows that capsizing is caused by broaching, loss of stability on a wave crest, or bow diving.
Received for publication on Jan. 20, 1999; accepted on July 6, 1999 相似文献
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By utilizing a four-degrees-of-freedom numerical model with dense grids of control parameters and the sudden-change concept,
the qualitative aspects of the nonlinear motions of a fishing vessel complying with the International Maritime Organization's
intact stability criteria in following and quartering seas were intensively explored. As a result, capsizing due to broaching,
capsizing without broaching, broaching without capsizing, stable surf-riding, and steady periodic motion were identified.
The natures of the boundaries of these motions in the control parameter plane were investigated, and the effects of the initial
conditions and the nonlinearity of calm-water maneuvering forces are also discussed. Furthermore, comparisons with a model
experiment showed that the numerical model used here qualitatively explains capsizing phenomena, but quantitatively overestimates
the danger of capsizing.
Received: June 11, 2001 / Accepted: October 9, 2001 相似文献
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The probability of capsize of purse seiners in irregular beam seas and the effect of freeboard height and metacentric height
on trapped water on the deck was investigated. The aim was to quantify a safety level that can be achieved by direct stability
assessment for this type of fishing vessel. The amount of trapped water on deck was numerically estimated using a hydraulic
flow assumption. The long-term capsizing probabilities were estimated using a piecewise linear approach together with wave
statistics from major Japanese fishing areas. The estimated safety level of capsizing probability was compared with that obtained
by the IMO weather criterion and by the water-on-deck criterion of the IMO Torremolinos Convention. Numerical results for
four typical Japanese purse seiners indicated that the effect of freeboard, on the amount of trapped water on deck, is more
important than that of the metacentric height. Besides the metacentric height and the freeboard, it was shown that the danger
of capsizing is a function of the rise of floor. The safety level obtained by the capsizing probability approach is generally
higher than that based on the IMO weather criterion. However, the water-on-deck criterion provides a higher safety level than
the capsizing probability approach for ships with a low rise of floor. 相似文献
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本文以一条起重船的作业状态的完整稳性计算为例,介绍了用NAPA软件中的MACRO来求出风压倾侧力矩和最小倾覆力臂,并把它们应用到相应衡准中的方法。 相似文献
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The authors have already examined a method for evaluating the capsizing probability of a ship in the dead ship condition based
on a piecewise linear approximation of the restoring arm. Here, this method is extended to ships with trapped water on deck.
This is because the stability of ships having a relatively high bulwark, such as fishing vessels, could substantially deteriorate
due to trapped water on deck. First, the mean amount of water trapped on deck was estimated as a function of the significant
wave height and the mean wave period using a model experiment in irregular beam seas. Second, the restoring arm curve with
trapped water on deck was calculated hydrostatically and then approximated with a piecewise linear curve. Third, the roll
angle was estimated using a nonlinear and uncoupled equation of absolute roll angle under stochastic wave and wind exciting
moments. The short-term and long-term capsizing probabilities were calculated for a fishing vessel operating off Kyushu. Numerical
results quantitatively demonstrated that the effect on capsizing probability of trapped water on deck cannot be ignored when
accurately evaluating the stability of fishing vessels. 相似文献
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This paper presents a methodology called SHARC developed for the simulation and analysis of a ship's damage stability and ULS conditions following a collision. SHARC combines three types of methods: advanced nonlinear finite element simulations that simulate the collision scenario, a dynamic damage stability simulation tool called SIMCAP, and a modified Smith method for the ULS analysis of a collision-damaged ship structure. The novelty of the presented methodology is that it can be used for real-time simulations to study the ingress of water through the damage opening of a struck vessel and how it affects the ship's stability, structural integrity (ULS) and survival capability against, e.g., capsizing. The results for an intact and a damaged oil tanker under noncorroded and corroded structural conditions and various sea states are presented to demonstrate the features of SHARC. 相似文献
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介绍了研究船舶在随机海浪上的稳性的三种方法:时域仿真、迈尔尼科夫法和首次穿越理论。对国内外运用这些方法研究船舶稳性的已有工作和最新进展做了综述。 相似文献