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介绍顶推船队耐波性试验,测量不同航速、不同浪向角对应的驳船和推轮纵摇角、横摇角、重心处垂向加速度和升沉幅值、驳船连接装置处垂向加速度,并对结果进行分析。 相似文献
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现有海洋顶推运输的优点是造价低,在经济航距以内其运输成本也低;缺点是联结力大,阻力大,因而经济航距受到限制,缩小了其适用范围,在分析了海洋顶推运输优缺点及其成因的基础上,找出发扬优点,抑制缺点以致消除缺点的途径-使携船微型化,将居住和驾驶处所由推船移至驳船,进而使推船形体微型化,微型推船将有效减小推驳船队的联结力、阻力和造价,而整体联结的微推船队则将这些优点推向极点。后者既是极优的推驳船队,又是自航船制造技术的一次革新。 相似文献
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为了探索凿岩机在甲板驳轨道上滑移对船舶运动响应和系泊缆力的影响,以3 850 DWT甲板驳船为研究对象,应用水动力分析软件ANSYS的AQWA模块,分析凿岩机在轨道前端、中部和后端3种凿岩工况,并对比驳船运动响应和系泊缆力的差异。分析结果表明:凿岩机在船上不同位置凿岩会使驳船纵摇和横摇发生明显变化;不同油水所导致排水量的不同,对驳船横摇纵摇响应也有一定的影响,不同工况下驳船系泊缆力的变化不大。研究结果可为大型设备在甲板驳船上作业的评估、选型和应对措施提供一定的借鉴和参考。 相似文献
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一、顶推驳船队与机动驳顶推船队是两种最好的内河散货运输方式 顶推驳船队在内河大宗散货运输中显出了无可比拟的优越性,在世界各国航道条件好的地方推广很快.顶推驳船队越大,其优越性越显著,但是相应对航道条件要求越严格. 相似文献
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本文根据苏北大运河现状,通过技术经济论证,得出发展性能优良的机动船是十分必要的。对于不同的航线,推荐了三种不同的机动船型,并且得出,顶推驳船型和机动驳船型及其他船型可以共同发展。 相似文献
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文章探讨驳船吊挂沉放法进行沉管管段的沉放作业过程中,驳船升沉运动和波浪联合作用对沉管管段运动特性的影响。采用边界元方法求解作用在沉管管段的波浪力,驳船升沉运动考虑为简谐运动,应用四阶Runge-Kutta方法求解沉管管段的运动方程。通过数值算例分析,探讨了驳船做不同振幅与不同相位的升沉运动和波浪联合作用下沉管管段的运动特性。 相似文献
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Two coaxial vertical cylinders-one is a riding hollow cylinder and the other a solid cylinder of greater radius at some distance above an impermeable horizontal bottom,were considered.This problem of diffraction by these two cylinders,which were considered as idealization of a buoy and a circular plate,can be considered as a wave energy device.The wave energy that is created and transferred by this device can be appropriately used in many applications in lieu of conventional energy.Method of separation of variables was used to obtain the analytical expressions for the diffracted potentials in four clearly identified regions.By applying the appropriate matching conditions along the three virtual boundaries between the regions,a system of linear equations was obtained,which was solved for the unknown coefficients.The potentials allowed us to obtain the exciting forces acting on both cylinders.Sets of exciting forces were obtained for different radii of the cylinders and for different gaps between the cylinders.It was observed that changes in radius and the gap had significant effect on the forces.It was found that mostly the exciting forces were significant only at lower frequencies.The exciting forces almost vanished at higher frequencies.The problem was also investigated for the base case of no plate arrangement,i.e.,the case having only the floating cylinder tethered to the sea-bed.Comparison of forces for both arrangements was carried out.In order to take care of the radiation of the cylinders due to surge motion,the corresponding added mass and the damping coefficients for both cylinders were also computed.All the results were depicted graphically and compared with available results. 相似文献
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Fast evaluation of ship-bridge collision force based on nonlinear numerical simulation 总被引:1,自引:0,他引:1
HUZhi-qiang GUYong-ning GAOZhen LIYa-ning 《船舶与海洋工程学报》2005,4(1):8-14
The max collision force of ship-bridge collision is one of the most important references for bridge design. By means of nonlinear digital simulation method, the collision forces of the collisions between rigid bridge pier and ship bow were calculated out for four different ships, whose tonnages are 5 000, l0 000,50 000 and 60 000 DWT respectively. Curves of collision force-penetration and absorbed energy-penetration are obtained, and the data of the max loads are then summarized. On the basis of these curves and data, a set of curves describing the relationships between max collision forces and tonnages of the ships are successfully presented, by which the max collision forces of the ships-bridge with different tonnages and in different velocities can be estimated easily and reliably. 相似文献
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Nowadays,there are many studies conducted in the field of marine hydrodynamics which focus on two vessels traveling and floating in sufficiently close proximity to experience significant interactions.The hydrodynamic behavior of parallel moving ships in waves is an interesting and important topic of late.A numerical investigation has been carried out for the prediction of wave exciting forces and motion responses of parallel moving ships in regular waves.The numerical solution was based on 3D distribution technique and using the linear wave theory to determine the exciting forces and ship's motion.The speed effects have been considered in the Green function for more realistic results.The numerical computations of wave exciting forces and motion responses were carried out for a Mariner and Series 60 for the purpose of discovering different Froude numbers and different separation distances in head sea conditions.Based on the numerical computations,it was revealed that the sway,roll and yaw have a significant effect due to hydrodynamic interaction. 相似文献
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分析波浪力的理论分布 ,用不同算式计算直墙上波浪作用力 ,结合有关试验数据 ,讨论波浪力大小与波向、建筑物长度的关系 ,并对如何减小波浪力提出几点看法。 相似文献
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文章基于SPH方法和FEM/DEM方法建立了SPH-FEM/DEM的二维流固耦合数值模型,模拟了在波浪荷载作用下斜坡上的护面块体内部的应力分布。结构物的水动力条件采用SPH方法模拟,结构物边界采用虚粒子模拟,护面块体结构的受力、运动和变形采用FEM/DEM方法模拟。不同块体间的接触力采用基于势函数的罚函数法来计算,采用中心差分的显式方法来求解有限元单元的变形。应用ANSYS软件和数值模型对静水压力作用下的混凝土方块的内部应力分布进行了比较模拟分析,验证了所建立的耦合数学模型。通过数值计算给出了波浪作用下位于斜坡上的护面块体的动水压力和块体内部的应力分布,讨论了块体内不同角点位置处的应力变化特性。 相似文献
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针对船舶、航空航天等工程领域中板、壳类结构振动噪声评价问题,将广泛应用于控制工程中的模态滤波理论引入到结构振动评估领域,建立了一种估算结构空间均方振速的新方法.该方法的特点是能在激励源信息未知的情况下,以布置在结构表面有限个振动传感器测量得到的振动响应作为主要输入,估算板、壳类结构的空间均方振速,从而评价结构的整体振动状态.依据该方法对一矩形平板结构受点力、线力和面力等3种典型的激励源作用下,通过少量结构振动测点的振动信息,分别对其空间均方振速进行了数值验证;同时利用一水下加肋圆柱壳结构进行了试验验证.数值和模型试验验证结果表明:利用该方法评估得到的振动速度谱线特征与精确解和实测值基本一致,评估误差在2 dB以内,满足工程应用精度要求.该方法可以应用于工程中板、壳类结构振动噪声评价和振动状态的在线监测评估. 相似文献