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某型舰船水下爆炸冲击波载荷作用下结构动态响应数值仿真研究 总被引:2,自引:0,他引:2
为保证舰船安全性,提高舰船生命力,舰船在水下爆炸冲击波载荷作用下动态响应,是船舶结构动力学研究的重要课题之一。采用MSC.DYTRAN有限元程序,运用数值仿真技术研究了某型水面舰船在水下爆炸冲击波载荷作用下的动态响应。分别从结构变形损伤、应力应变响应、变形能吸收和冲击环境等几个方面研究了舰船结构在水下爆炸冲击波载荷作用下的响应特性。 相似文献
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为探究水下接触爆炸载荷对大型舰船水下舷侧多舱防护结构毁伤的研究进展,从水下接触爆炸下多舱防护结构载荷特性及结构动响应2个方面综述国内外研究现状。对水下接触爆炸产生的冲击波载荷、复杂边界条件下的气泡载荷及高速破片侵彻液舱引起的冲击波载荷的研究现状进行综述;同时对水下接触爆炸下多舱防护结构的舷侧外板结构(背空板)、液舱结构及夹芯结构的响应研究现状分别进行综述。总结国内外学者对相关问题的研究成果,指出目前研究工作中存在的盲点,提出需要进一步研究和解决的问题,旨在为多舱防护结构的研究、设计和优化工作提供参考。 相似文献
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水下爆炸对舰船结构损伤特征研究综述 总被引:2,自引:0,他引:2
鱼雷、水雷等水中兵器是舰船生命力的主要威胁之一。舰船水下爆炸已成为国际上研究的热点问题,虽然,近年来在舰船水下爆炸领域取得了一系列丰硕的研究成果,但迄今为止,水下爆炸冲击波、气泡运动及其对舰船结构的毁伤机理与规律仍未被完全揭示。针对此研究现状,首先分析了水下爆炸载荷特性,总结了水下爆炸对舰船结构的毁伤特性;其次,从应用研究和科学研究两方面,概括了舰船水下爆炸实验、理论分析以及数值方法方面的研究进展,总结了在基础研究方面存在的问题,旨在为舰船抗爆抗冲击相关研究提供参考。 相似文献
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舰船抗爆领域水下爆炸载荷研究进展 总被引:2,自引:0,他引:2
海战中水下爆炸载荷是舰船的重要威胁之一,为了给舰船抗爆研究提供准确的载荷输入,需要对载荷进行系统研究。通过查阅大量文献,介绍了国内外舰船抗爆领域水下爆炸载荷的研究概况,从冲击波载荷和气泡载荷两个方面总结了该领域的研究进展。由于冲击波载荷的研究比较成熟,重点对气泡运动方程、气泡射流等气泡阶段的研究工作进行了总结和分析。并且在分析前人工作的基础上对该领域有待进一步解决的问题和发展趋势进行了展望,为该领域内研究工作的开展提供一定参考。 相似文献
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设计了船舱浮筏系统的水下爆炸试验装置,测试了浅水域中爆炸的水下爆炸载荷,分析了存在结构反射时的冲击波和气泡脉动压力的幅值、比冲量和能量密度,指出以低频成分为主的气泡脉动压力,对舰船设备隔离系统的冲击响应产生重要的作用.并对水下爆炸载荷作用下船舱浮筏系统的冲击响应进行分析,其结果对于研究舰船设备的抗冲击性能具有参考价值. 相似文献
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水下爆炸作用下船舱浮筏系统的冲击响应试验研究 总被引:3,自引:0,他引:3
设计了船舱浮筏系统的水下爆炸试验装置,测试了浅水域中爆炸的水下爆炸载荷,分析了存在结构反射时的冲击波和气泡脉动压力的幅值、比冲量和能量密度,指出以低频成分为主的气泡脉动压力,对舰船设备隔离系统的冲击响应产生重要的作用。并对水下爆炸载荷作用下船舱浮筏系统的冲击响应进行分析,其结果对于研究舰船设备的抗冲击性能具有参考价值。 相似文献
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水下爆炸可对舰船等水中结构造成严重毁伤,严重危及舰船的生命力和作战能力,是学术和工程界研究的难点问题之一。水下爆炸载荷包括冲击波和气泡,其对水中结构造成不同模式的毁伤。长期以来,研究人员在水下爆炸载荷及其对水中结构的毁伤方面均进行了大量的研究工作,取得了巨大进展和重要研究成果。但是由于该问题的难度和复杂性,迄今仍存在许多艰涩的力学难题有待攻克和解决。因此,从理论研究、数值模拟和实验研究等方面综述水下爆炸载荷及其对舰船毁伤的研究进展,并在此基础上提出未来需要进一步展开的研究工作,旨在为水下爆炸与舰船毁伤、水下爆炸威力等相关研究提供参考。 相似文献
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Bubble load in a noncontact underwater explosion can cause the ship hull global response and local response. In current literature, the ship hull is usually simplified as a hull girder to analyze its global response. However, literature dealt with the local response of a 3-D surface ship hull subjected to an underwater bubble were limited. This investigation develops a procedure which couples the finite element method with doubly asymptotic approximation (DAA) method to study the problem of transient responses of a ship hull structure subjected to an underwater explosion bubble. Using a 3-D ship model as examples, the global and local responses of the ship model in vertical, transverse and longitudinal directions are performed in detail. The acceleration, velocity and displacement time histories are presented. The characteristics of both the global and local responses of the ship model are discussed. The numerical results show that besides global whipping response, the ship hull also sustains severe local responses in different directions subjected to underwater explosion bubble jetting, which should be taken into consideration. 相似文献
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With increases in ship size and speed, shipboard vibration becomes a significant concern in the design and construction of vessels. Excessive ship vibration is to be avoided for passenger comfort and crew habitability. In addition to the undesired effects on humans, excessive ship vibration may result in the fatigue failure of local structural members or malfunctioning of machinery and equipment. The propeller induces fluctuating pressure on the surface of the hull, which induces vibration in the hull structure. These pressure pulses acting on the ship hull surface above the propeller are the predominant factor for vibrations of ship structures are taken as excitation forces for forced vibration analysis. Ship structures are complex and may be analyzed after idealization of the structure. Several simplifying assumptions are made in the finite element idealization of the hull structure. In this study, a three-dimensional finite element model representing the entire ship hull, including the deckhouse and machinery propulsion system, has been developed using solid modeling software for local and global vibration analyses. Vibration analyses have been conducted under two conditions: free–free (dry) and in-water (wet). The wet analysis has been implemented using acoustic elements. The total damping associated with overall ship hull structure vibration has been considered as a combination of the several damping components. As a result of the global ship free vibration analysis, global natural frequencies and mode shapes have been determined. Moreover, the responses of local ship structures have been determined as a result of the propeller-induced forced vibration analysis. 相似文献
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This paper examines the vibration characteristics and vibration control of complex ship structures. It is shown that input mobilities of a ship structure at engine supports, due to out-of-plane force or bending moment excitations, are governed by the flexural stiffness of the engine supports. The frequency averaged input mobilities of the ship structure, due to such excitations, can be represented by those of the corresponding infinite beam. The torsional moment input mobility at the engine support can be estimated from the torsional response of the engine bed section under direct excitation. It is found that the inclusion of ship hull and deck plates in the ship structure model has little effect on the frequency-averaged response of the ship structure. This study also shows that vibration propagation in complex ship structures at low frequencies can be attenuated by imposing irregularities to the ring frame locations in ships. Vibration responses of ship structures due to machinery excitations at higher frequencies can be controlled by structural modifications of the local supporting structures such as engine beds in ships. 相似文献
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Experimental hydroelasticity has not followed the rapid evolution of its computational counterpart. Hydroelastic codes have changed significantly in the past few decades, moving to more detailed modelling of both the structure and the fluid domain. Physical models of ships are, even today, manufactured with a very simplified structural arrangement, usually consisting of a hollow rectangular cross section. Appropriate depiction of the internal structural details ensures that properties relevant to antisymmetric vibration are scaled accurately from the real ship to the model. Attempts to create continuous, ship-like structures had limited success, as manufacturing constraints did not allow for much internal structural detail to be included. In this investigation, the first continuous model of a ship with a detailed internal arrangement resembling a container ship is designed, produced using 3D printing and tested in waves. It is demonstrated that the global responses of the hull in regular head waves agree well with theory and past literature, confirming that such a model can represent the behaviour of a ship. Furthermore, it is found that the model is capable of capturing local responses of the structure, something that would be impossible with “traditional” hydroelastic ship models. Finally, the capability of the model to be used to investigate antisymmetric vibrations is confirmed. The methodology developed here opens a whole new world of possibilities for experiments with models that are tailored to the focus of the investigation at hand. Moreover, it offers a powerful tool for the validation of modern state-of-the-art hydroelastic codes. Ultimately, it creates the next step in the investigation of dynamic responses of ship structures, which contribute significantly to accumulating damage of the hull. Better understanding of these responses will allow designers to avoid over-engineering and use of big safety factors to account for uncertainties in their predictions. 相似文献
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During ship collisions part of the kinetic energy of the involved vessels immediately prior to contact is absorbed as energy dissipated by crushing of the hull structures, by friction and by elastic energy. The purpose of this report is to present an estimate of the elastic energy that can be stored in elastic hull vibrations during a ship collision.When a ship side is strengthened in order to improve the crashworthiness it has been argued in the scientific literature that a non-trivial part of the energy released for structural deformation during the collision can be absorbed as elastic energy in global ship hull vibrations, such that with strong ship sides less energy has to be spent in crushing of the striking ship bow and/or the struck ship side.In normal ship–ship collision analyses both the striking and struck ship are usually considered as rigid bodies where structural crushing is confined to the impact location and where local and global bending vibration modes are neglected. That is, the structural deformation problem is considered quasi-static. In this paper a simple uniform free–free beam model is presented for estimating the energy transported into the global bending vibrations of the struck ship hull during ship–ship collisions. The striking ship is still considered as a rigid body. The local interaction between the two ships is modeled by a linear load–deflection relation.The analysis results for a simplified model of a struck coaster and of a large tanker show that the elastic energy absorbed by the struck ship normally is small and varies from 1 to 6% of the energy released for crushing. The energy stored as elastic global hull girder vibrations depends on the ship mass, the local stiffness of the side structure, and of the position of contact. The results also show that in case of highly strengthened ship sides the maximum global bending strains during collisions can lead to hull failure. 相似文献
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The paper presents an overview of studies of slamming on ship structures. This work focuses on the hull slamming, which is one of the most important types of slamming problems to be considered in the ship design process and the assessment of the ship safety. There are three main research aspects related to the hull slamming phenomenon, a) where and how often a slamming event occurs, b) slamming load prediction and c) structural response due to slamming loads. The approaches used in each aspect are reviewed and commented, together with the presentation of some typical results. The methodology, which combines the seakeeping analysis and slamming load prediction, is discussed for the global analysis of the hull slamming of a ship in waves. Some physical phenomena during the slamming event are discussed also. Recommendations for the future research and developments are made. 相似文献
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《Marine Structures》2004,17(5):385-402
Structural components are prone to corrosion damage, especially when exposed to a sea environment. This article describes an investigation on the effects of local corrosion applied to plates and stiffened panels typically found in ship structures. Finite element investigations of initial buckling, ultimate collapse and post-ultimate responses are presented and described through the use of load-shortening collapse curves. Geometric imperfections and residual stresses were included in the model and results are compared to analytical calculations and available experimental measurements. This improved knowledge of the structural integrity of a damaged ship structure can be used to develop more efficient maintenance practices. 相似文献