Model Test of Sand Restraining Force on Pipeline     

Zhang Jianguo Yan Chi Yan Shuwang Lecturer  Dept. of Hydraulic Eng.  Tianjin University  Tianjin Associate Professor  Dept. of Hydraulic Eng.  Tianjin University  Tianjin Professor  Dept. of Hydraulic Eng.  Tianjin University  Tianjin 《中国海洋工程》1996,(1)

This paper describes the model tests for determining the axial friction and the lateral resistance of sand to pipeline by using fine sand and prototype pipeline, and the calculation method based on limit analysis theory is verified. The effect of cyclic loading is considered in the test.  相似文献   

Shear Failure of a Clamped Dented Tubular Beam Under Lateral Impact   总被引：1，自引：0，他引：1  

Wang Deyu  Zhang Shanyuan Associate Prof.  Depart  of Naval Archi.  Ocean Engineering  Shanghai Jiaotong University  Shanghai Prof.  Research Institute of Applied Mechanics  Taiyuan University of Technology  Taiyuan 《中国海洋工程》1996,(2)

- The shear failure of a rigid-plastic dented clamped tubular beam under the lateral impact of a mass is investigated. Both the denting and the impact point are in the middle span of the beam. It is assumed that denting does not spread during the shear sliding. Numerical results show that the axial force and lateral deflection of the beam are very small at the moment of the occurence of shear failure, which means that the finite deformation effect can be neglected in the shear failure analysis. Also, some aspects of the initial impact energy are investigated.  相似文献   

长江口及济州岛邻近海域温、盐、密度的跃层现象     

孙日彦  周培强  赵继胜 《中国海洋大学学报(自然科学版)》1990,(1)

本文根据CTD观测资料,分析了研究海区的温、盐、密度跃层的分布与变化,讨论了逆温逆盐层的分布区域,并从跃层角度出发,分析了深层水的涌升,黄海冷水团的上边界以及台湾暖流在东海北部的影响范围。  相似文献   

汞对三角褐指藻生长影响的研究——汞与浮游植物相互作用(Ⅰ)     

吕小乔  孙秉一  史致丽 《中国海洋大学学报(自然科学版)》1990,(4)

采用连续培养技术研究汞对三角褐指藻生长的影响。当长时间接触含HgCl_2(范围5～25μg/dm~3)的培养介质中,得到结果表明,藻的生长速率随汞浓度增加而降低,细胞所排泄的有机物增加,对细胞中Chl-a的含量有一定程度影响,并抑制对硝酸盐和磷酸盐的吸收。在最初的2—4天中,汞对生物化学过程影响最大。  相似文献   

Optimal Design for Main Dimensions of a 75000t Floating Production and Storage Vessel     

Tan Jiahua  Ma Wei  Pan Bin Associate Professor  Shanghai Jiao Tong University  Shanghai Lecturer  shanghai Jiao Tong University  Shanghai 《中国海洋工程》1992,(1)

The basis, process and results of the demonstration of the main dimensions of a 75000t floating production and storage vessel are discussed in this paper. A simple but reliable orthogonal design method is applied in the main dimension optimization. The ideas of gradual approximation and feedback from various aspects are put into effect. During the demonstration, in order to make the model tally with the actual situation, the draft design is closely related to the computational analysis, so that the demonstration model can be verified at any time; the handling of the overall system is closely related to the research of each item, which is beneficial not only to the mastery of various regularities, but also to the balance of decisions. Finally, according to the computational results and the regularities obtained from analysis, the main dimensions are determined.  相似文献   

Calculating Method and Verification of Wave Pressure Distribution on the Breast Wall of Mound Breakwater     

Lu Wujiang Associate Prof.  Hohai University    Nanjing 《中国海洋工程》1992,(4)

In this paper, the calculating charts and formulae about wave pressure on the breast wall are derived with seven parameters on the basis of physical model study. The verification shows that the charts agree with the example, and are adopted in the Specifications of Fishery Harbours Breakwater by the Ministry of Agricultures.  相似文献   

Elasto-Plastic Analysis of Tubular Joints of Offshore Platforms by Finite Element Method     

Chen Tieyun Zhu Zhenghong Professor  Dept. of Naval Architecture  Ocean Engineering  Shanghai Jiao Tong University  Shanghai Lecturer 《中国海洋工程》1991,(1)

The plastic node method is reformulated by the variational principle and is applied to elasto-plastic finite element analysis of tubular joints, eventually including the effect of internal and external gussets, stiffener rings, etc., if necessary. Four different joints are studied here in detail for the elasto-plastic behavior, the strain at the hot spot, the strain concentration factor around the intersection line, and the propagation of the plastic region with loading up to collapse in order to determine the ultimate strength, safety factor, and development of the plastic field. The present results are in good agreement with the experimental results.  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   

Origin and evolution of alkali basaltic magma in the Okinawa Trough     

Zhang Jiaqiang  Sun Yongfu  Jiang Xiaoli 《海洋学报(英文版)》2000,19(3):115-129

I~IOXThe Okinawa Trough is an extending back--arc basin between the East China Sea Shelf andthe Ry'Ukyu Island Arc of Japan. There are widespreadly distributing acid pumice in the troughand a little basalt just in some area of the extending center. There have been some detailed rePOrtsabout the mineralogy and petrochemical feature of the subalkali tholeiite and alkali trachyte in thetrough (Zhai and Gan, 1995; Li et al., 1997; Qin and Zhai, 1988). This paper mainly reportselectron mic…  相似文献