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91.
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
92.
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
93.
Maximum Entropy Estimation of n-Year Extreme Waveheights 总被引:3,自引:4,他引:3
A new method for estimating the n (50 or 100) -year return-period waveheight, namely, the extreme waveheight expected to occur in n years, is presented on the basis of the maximum entropy principle. The main points of the method are as follows: (1) based on the Hamihonian principle, a maximum entropy probability density function for the extreme waveheight H, f(H)= aH^γe-^βH4 is derived from a Lagrangian function subject to some necessary and rational constraints; (2) the parameters α,β, and γ in the function me expressed in terms of the mean H, variance V=(H-H^-)^2—— and bias B = (H - H^-)^3——; and (3) with H^-, V and B estimated from observed data, the n-year return-period wave height Hn is computed in accordance with the formula 1/1-F(Hn)=n, where F( Hn ) is defined as F( Hn ) = ∫0^Hnf(H)dH .Examples of estimating the 50 and 100-year return period waveheighls by the present method and by some currently used method from observed data acquired from two hydrographic stations are given. A comparison of the estimated results shows that the present method is superior to the others. 相似文献
94.
1 .IntroductionNumericalmodelsmostwidelyusedforseaenvironmentandsedimenttransportfocusonsolvingseriesofdifferentialequations .Theinputandoutputofanumericalmodelareconsideredasdecisivefactors .Butinrealitythecausesofnaturaleventssuchasmeteorological,astronomical,oceanograph ic ,geomorphologicandgeophysicalfactorsarerandom .Therearemanyuncertaintiesinvolvedininputfactorsinnumericalmodels .Correspondinglytheoutputsofnumericalmodelsarealsorandom .There fore ,theoutputparametersofnumericalmodelsca… 相似文献
95.
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
96.
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
97.
Wei Shoulin Xiao Rong Professor Ocean University of Qingdao Qingdao . Teaching Assistant Ocean University of Qingdao Qingdao 《中国海洋工程》1994,(1)
- In this paper, a numerical computation method is developed for the computation of current field in the tidal zone, using the well-point method and ADI method. The computational results agree well with the general variation of current field in the tidal zone. 相似文献
98.
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
99.
试论我国海岸侵蚀信息系统的建立 总被引:6,自引:1,他引:6
本文通过对我国海岸侵蚀特点的分析,阐述了建立海岸侵蚀信息系统的必要性和基本方法,并给出了相应的结论。 相似文献