A Generalized Point Conforming Rectangular Plate Element     

Wang Deyu Chen Tieyun Associate Professor 《中国海洋工程》1995,(3)

- A generalized point conforming rectangular element for plate bending is proposed. The present element displacement field can not only satisfy the continuity of normal displacement and its derivative at the element node, but also satisfy the generalized continuity at the middle point of each element boundary, where the generalized conforming condition is to make the non-conforming residual to be minimum. Numerical results show that the proposed element is more accurate than the ordinary 4-node non-conforming rectangular plate element (ACM element).  相似文献   

Effect of Band Width on Fatigue Life under Random Stress Response     

Wu Yisheng Associate Professor 《中国海洋工程》1992,(2)

A fatigue life estimation method for offshore structures under random stress response is studied in this paper. The method of broad band cumulative frequency number is used to determine the effect of band width of stress frequency spectra on fatigue. A formula of correction factor for fatigue under broad band stress spectra is suggested and compared with that given by P. H. Wirsching.  相似文献   

Transitional waters: A new approach, semantics or just muddying the waters?     

D.S. McLusky  Editor  M. Elliott  Member of Editorial Board 《Estuarine, Coastal and Shelf Science》2007,71(3-4):359-363

Estuarine, Coastal and Shelf Science has throughout its history considered a diverse range of habitats including estuaries and fjords, brackish water and lagoons, as well as coastal marine systems. Its articles have reflected recent trends and developments within the estuarine and coastal fields and this includes the changing use of well-accepted terms. The term “transitional waters” first came to prominence in 2000 with the publication of the Water Framework Directive of the European Communities [European Communities, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal of the European Communities 43 (L327), 75 pp.], where “transitional waters” are defined as “bodies of surface water in the vicinity of river mouths which are partially saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows”. The inclusion of the term transitional waters in our own aims and scope reflects the evolution of language in this subject area, encompassing tidal estuaries and non-tidal brackish water lagoons. This article reflects on some of the difficulties posed by the use of the term and its attempts to be inclusive by incorporating fjords, fjards, river mouths, deltas, rias and lagoons as well as the more classical estuaries. It also discusses the problems of including in the term river mouths discharging either into predominantly brackish areas such as the Baltic Sea, or into freshwater-poor areas bordering the Mediterranean.  相似文献   

Numerical Study on the Probability of Fatigue Failure of a Semi-Submerged Platform Structure     

Yu Jianxing  Hu Yunchang  Wang Yehong  YuHongjie Associate Professor  Tianjin University  Tianjin  Professor  Tianjin University  Tianjin  Postgraduate for Master Degree  Tianjin University  Tianjin 《中国海洋工程》1994,(4)

On the basis of Miner's linear cumulative damage theorem, random variables are introduced to evaluate objectively the fatigue damage of a semi-submerged platform structure and a method is presented to analyze the fatigue reliability of the structure in its design life. The reliability of the method is verified through numerical examples and some conclusions are drawn, which have certain guiding and reference value for design and inspection.  相似文献   

Some Considerations in Design and Construction of the Wei-Liu Water Supplying Submarine Pipeline     

Fan Yunlin  Chang Dezhi Associate Professor  Dept. of Ocean Eng.  Tianjin University Engineer  Construction Committee of Weihai City  Shandong Province 《中国海洋工程》1991,(4)

The Wei- Liu water supplying submarine pipeline is at present the longest one of the kind in China. It is about 4 kilometers long from Weihai City to Liugong Island in Shandong province. It took only half a year to design and construct it. The project was of a high economic efficiency and some practical experiences were achieved. In this paper a general introduction to the design and construction of this pipeline is presented and such problems as the stability of the pipeline in very soft clay, design of curved slide for launching and estimation of dragging forces are expounded.  相似文献   

A Study on Impervious and Heat-Insulating Performance of Geomembrane Composites Within Breakwater     

Tao Tongkang  Yu Long  Yan Jun Dong Zhiyong Prof.  Senior Engineer  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Graduate Student  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Engineer  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Associate Professor  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1997,(2)

This paper investigates the performance of geomembrane composites used as impervious andheat-insulating lining within a breakwater for a power station.The seepage field,distribution ofstress-strain contour and seepage discharge of hot water which has been treated as the inner thermalsource in the calculation of heat-insulation,have been given by three-dimensional calculation method coup-ling seepage with stress.The results indicate that the impervious and heat-insulation effect ofgeomembrane composites is significant.  相似文献   

Evalution of Application of p-y Curve Method in Offshore Engineering Foundation     

Jin Weiliang  Zhu Yuming  Li Linpu Associate Professor  Dr. -Eng.  Zhejiang University  Hangzhou Engineer  Metallurgical Building Design  Research Institute  Beijing Associate Professor  Dalian University of Technology  Dalian 《中国海洋工程》1993,(4)

- Based on the Mohr-Coulomb failure principle and Rankine's theory, the laterally loaded pile ultimate resistance formulas of sand and soft clay proposed by Reese and Matlock respectively are discussed in this paper. The authors put forward the modified ultimate resistance formulas on the basis of which the ultimate resistance formula is developed for horizontally loaded pile in multi-layer soil in consideration of the effect of the overburden soil pressure on the calculation of soil layer. It is significant to the correct application of the ultimate resistance formulas in API and ZCS Rules into offshore engineering.  相似文献   

Investigation of Internal Turret Mooring System for Oil Production Storage Vessels     

Ma Zhiliang  Huang Xianglu  Ma Peisun Fan Genfa  Yu Xiangsan  Jin Dexian Professor  Shanghai Jiao Tong University  Shanghai Associate Professor  Shanghai Jiao Tong University  Shanghai Research Fellow  Shanghai Jiao Tong University  Shanghai 《中国海洋工程》1991,(4)

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Investigation on Settling Characteristics of Floes in the Changjiang Estuary, China     

Li Yan  Wang Yaqin LinYian Associate Professor  Second Institute of Oceanography  State Oceanic Administration  Hangzhou  Senior Engineer  Second Institute of Oceanography  State Oceanic Administration  Hangzhou 《中国海洋工程》1995,(3)

- Settling characteristics of floes, including relative settling velocity, relative flocculation coefficient and flocculation exponent, are obtained by the suspended load equations for different size fractions. Data of the Changjiang Estuary suggest that level of flocculation changes from river section, river mouth (turbidity maximum) to offshore area in sequence of low, very high and high. The settling characteristics of floes reflected by in situ estimation performs a similar feature as that obtained from still water experiment.  相似文献   

The New Form of Time-Dependent Mild Slope Equation for Random Waves     

Zhang Yonggang  Li Yucheng Teng Bin Doctor Degree Candidate  The National Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian Professor  The National  Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian Associate Professor  The National Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian 《中国海洋工程》1995,(4)

The mild-slope equation derived by Berkhoff (1972), has widely been used in the numerical calculation of refraction and diffraction of regular waves. However, it is well known that the random sea waves has a significant effect in the refraction and diffraction problems. In this paper, a new form of time-dependent mild slope equation for irregular waves was derived with Fade approximation and Kubo's time series concept. The equation was simplified using WKB method, and simple and practical irregular mild slope equation was obtained. Results of numerical calculations are compared with those of laboratory experiments.  相似文献