Static Analysis of Collision Strength of Offshore Platform     

Li Runpei Chen Weigang Gu Yongning Professor  Shanghai Jiao Tong University  Shanghai Assistant  Shanghai Jiao Tong University  Shanghai 《中国海洋工程》1996,(1)

In this paper a numerical analysis method combining FEM incemental technique with limit analysis concept is proposed for the study of the static strength of offshore platform in collision. Large deformation and plasticity are accounted for and the limit yield surface expressed by generalized stress for a tubular section is derived. The modified stiffness matrix of space beam element is formulated by Plastic Node Method. The buckling behavior of beam columns can also be taken into account. It can trace the generation of plastic hinges during loading and finally the ultimate strength of offshore platform against collision is obtained.  相似文献   

波浪作用下异重流运动特性研究   总被引：3，自引：0，他引：3  

李大山  任汝述 《海洋工程》1996,(4)

本文通过水槽试验和理论分析手段对波浪作用下异重流运动特性进行了研究，应用流体运动基本方程推导了异重流在水平底面运动时的运动速度、厚度和流量表达式。结果表明，计算结果与水槽试验较一致  相似文献   

The synchronous coupling of a third-generation wave model and a two-dimensional storm surge model     

M.Y. Zhang  Y.S. Li 《Ocean Engineering》1996,23(6):533-543

The interaction of waves and currents is studied by the dynamical coupling of a third generation wave model and a two-dimensional storm surge model. The coupling process of the two models is implemented synchronously. To estimate the effects of waves on the generation of storm surges, the theory of Janssen is used. The effects of the wave radiation stress on surge levels and the effects of storm-induced currents on waves are also investigated.The coupled wave and storm surge models have been tested by hindcasting two storm events in the northern South China Sea. The use of the Simth and Banke stress relation underestimates the surges by 10%. The inclusion of the radiation stress improves the accuracy of the computed results slightly by 2%. The introduction of a wave-dependent surface drag gives a significant improvement. The storm-induced currents clearly affect the wave characteristics at the peak stage. However, as far as the prediction of wave height is concerned, it is better not to consider the wave radiation stress in the storm surge model unless this is accompanied by a wave-dependent surface drag.  相似文献   

Wave-Current Forces on Slender Circular Cylinders   总被引：3，自引：0，他引：3  

Li Yucheng  Wang Fenglong  Kang Haigui Professor  Dalian University of Technology  Dalian Senior Engineer  Dalian University of Technology  Dalian Lecturer  Dalian University of Technology  Dalian 《中国海洋工程》1991,(3)

- A series model tests of wave forces by both regular and irregular waves combined with currents on single piles and bipiles in tandem and parallel arrays have been carried out. Based on Morison Equation, linear wave theory and linear wave spectrum theory as well, the characteristics of inline, lift and resultant forces on cylinders have been analyzed respectively. The drag, inertia and lift coefficients CD, CM and CL f皉 single piles related to KC number and the grouping effect coefficients of inline, lift and resultant forces on bipiles in tandem and parallel arrays related to KC number are given in this paper.  相似文献   

Numerical Simulation of Multi-Directional Random Seas     

Yu Yuxiu  Liu Shuxue  Li Li Professor  Dept. of Civil Engineering  Dalian University of Technology  Dalian Research Assistant  Dept. of Civil Engineering  Dalian University of Technology  Dalian 《中国海洋工程》1991,(3)

Multi-directional irregular waves are simulated on the basis of the given directional spectrum using a double summation model, a single direction per frequency model and a single summation model. Their results are compared. It is shown that the single direction per frequency model proposed in this paper can generate a realistic wave field. The effects of the model parameters on the simulated results are also studied in this paper and corresponding suggestions are given.  相似文献   

黄河入海泥沙对渤海和黄海沉积作用的影响   总被引：2，自引：0，他引：2  

秦蕴珊  李凡 《海洋科学集刊》1986,(27):125-136

渤海平均水深18m，最大水深70m，是一个较浅的海湾。黄海平均水深38m，其中部为水深大于50m的盆地。它们的共同特征是陆地环绕。沿岸河流输沙特征对沉积作用过程有重大影响，特别是黄河入海泥沙的影响尤为显著。 关于黄河人海泥沙对渤海和黄海沉积作用的影响，前人已从不同角度进行过讨论。黄河是世界上著名的多沙性河流。由于黄河尾闾长期以来不断发生变迁，纵横摆动于华北平原之上，交替注入渤海和黄海，因此，在讨论黄河入海泥沙在中国近海沉积中的作用时，必须把渤海和黄海作为一个整体，甚至南涉东海。本文试图在以往工作的基础上，概括讨论黄河入海泥沙对渤海和黄海海底沉积作用的影响。  相似文献   

人造海洋涌升流和海洋渔场   总被引：1，自引：0，他引：1  

李冠成  王秉坤  李明  范喆  王莉  卢佃清 《海洋技术学报》2003,22(2):74-78

针对渔业资源日趋减少和鱼产品需求不断增加的矛盾，探讨了建造海底山脉、人工制造海洋涌升流、从而人工制造优良海洋渔场的可行性，分析了我国建造海底山脉的水深、海底和海流条件。介绍了建造海底山脉的建筑方法和国际上建造海底山脉的最新动态。论述了我国在200n mile以内建造海底山脉的有利条件。  相似文献   

海上油井密封套管内海水冻胀特性试验分析     

孟广琳  李志军  隋吉学  高树刚  张波 《海洋通报》2000,19(1):34-40

1998年首次进行了海上油井密封套管内海水冻胀特性模拟试验,建立了一套各种参数的测量系统.文中介绍了管内海水冻结过程、海水过冷温度、结冰水温、轴向冻胀力以及管体应变测量结果.  相似文献   

关于波浪Boussinesq方程的研究   总被引：2，自引：0，他引：2  

李孟国  王正林  蒋德才 《中国海洋大学学报(自然科学版)》2002,32(3):345-354

对有关波浪 Boussinesq方程的研究成果进行了系统的归纳总结和评述 ,以期对本学科的发展起到一定的引导和促进作用  相似文献   

Measurement of nuclides of uranium and thorium series of disequilibrium using γ-spectroscopy   总被引：3，自引：0，他引：3  

Liu Guangshan  Huang Yipu  Li Jing  Ye Lin 《海洋学报(英文版)》2002,21(4):505-517

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒａｄｉｏｎｕｃｌｉｄｅｓｏｆｎａｔｕｒａｌｕｒａｎｉｕｍａｎｄｔｈｏｒｉｕｍｓｅｒｉｅｓｃａｎｂｅｕｓｅｄｔｏｔｒａｃｅｍａｒｉｎｅｐｒｏ ｃｅｓｓｏｆｖａｒｉｏｕｓｔｅｍｐｏｒａｌａｎｄｓｐａｔｉａｌｓｃａｌｅａｎｄｐｒｏｐｅｒｔｉｅｓｔｈａｔｐｒｏｖｉｄｅｐｌｅｎｔｉｆｕｌｉｎｆｏｒｍａｔｉｏｎａｂｏｕｔｐｈｙｓｉｃｓ,ｃｈｅｍｉｓｔｒｙ ,ｇｅｏｓｃｉｅｎｃｅａｎｄｂｉｏｌｏｇｙｏｆｏｃｅａｎｂｅｃａｕｓｅｔｈｅｙｈａｖｅｄｉｆｆｅｒｅｎｔｃｈｅｍｉｃａｌｐｒｏ…  相似文献