Reliability-Based Full-Life Cycle Optimum Design of Offshore Jacket Platform     

王立成  宋玉普 《中国海洋工程》2004,18(1):47-58

Based on the consideration of operation environment and structural property, an optimnm design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease, of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability eonstraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.  相似文献   

Simulation of Fully Nonlinear 3-D Numerical Wave Tank   总被引：6，自引：0，他引：6  

张晓兔滕斌  宁德志 《中国海洋工程》2004,18(1):59-68

A fully nonlinear numerical wave tank (NWT) has been simulated by use of a three-dimensional higher order bouodary element method (HOBEM) in the time domain. Within the frame of potential flow and the adoption of simply Rankine source, the resulting boundary integral equation is repeatedly solved at each time step and the fully nonlinear free surface boundary conditions are integrated with time to update its position and boundary values. A smooth technique is also adopted in order to eliminate the possible saw-tooth numerical instabilities. The incident wave at the uptank is given as theoretical wave in this paper. The outgoing waves are absorbed inside a damping zone by spatially varying artificial damping on the free surface at the wave tank end. The numerical results show that the NWT developed by these approaches has a high accuracy and good numerical stability.  相似文献   

Analysis　on　rupture　feature　of　a　great　complicated　earthquake　in　Kamchatka     

高原  郑斯华  周蕙兰  刘振  吴忠良 《地震学报(英文版)》1997,10(1):1-6

ＡｎａｌｙｓｉｓｏｎｒｕｐｔｕｒｅｆｅａｔｕｒｅｏｆａｇｒｅａｔｃｏｍｐｌｉｃａｔｅｄｅａｒｔｈｑｕａｋｅｉｎＫａｍｃｈａｔｋａＹＵＡＮＧＡＯ１）（高原）ＳＩＨＵＡＺＨＥＮＧ１）（郑斯华）ＨＵＩＬＡＮＺＨＯＵ２）（周蕙兰）ＺＨＥＮＬＩＵ２）（...  相似文献   

SENSITIVITY ANALYSIS OF HYDRAULIC GEOMETRY     

CAO Shuyou  This research was supported financially by the Foundation for Scholars Return from Abroad of State Educational Committee  the National Natural Science Foundation of China 《国际泥沙研究》1997,(3)

I.INTRODUCTIONThehydraulicgeometryofstablenaturalriversisdeterminedbyceftaincontrolfactors.suchassizeandgradationofboundarymaterial-sorting,transportandarmoring.planformofchannel.ballkstability.amongstothers.Ageometricmodelfornonuniformboundarymaterialhasbeenproposed(Cao,1996).Theentropy-basedthresholdbankprofiletheory(CaoandKnight,1996).thenext'solutionofthestablechannelparadox,basedonShionoandKnight's(1991)solutionofthedepthmean-averagedmomentumequationatthejunctionpointsareemployedto…  相似文献   

Source　parameters　of　the　Gonghe,Qinghai　Province,China,earthquake　from　inversion　of　digital　broadband　waveform　data     

许立生  陈运泰 《地震学报(英文版)》1997,10(2):143-159

ＳｏｕｒｃｅｐａｒａｍｅｔｅｒｓｏｆｔｈｅＧｏｎｇｈｅ，ＱｉｎｇｈａｉＰｒｏｖｉｎｃｅ，Ｃｈｉｎａ，ｅａｒｔｈｑｕａｋｅｆｒｏｍｉｎｖｅｒｓｉｏｎｏｆｄｉｇｉｔａｌｂｒｏａｄｂａｎｄｗａｖｅｆｏｒｍｄａｔａＬＩ－ＳＨＥＮＧＸＵ（许立生）ａｎｄＹＵＮ...  相似文献   

The effect of focal depth error on moment tensor inversion     

许力生  陈运泰 《地震学报(英文版)》1997,10(5):571-580

ＴｈｅｅｆｅｃｔｏｆｆｏｃａｌｄｅｐｔｈｅｒｏｒｏｎｍｏｍｅｎｔｔｅｎｓｏｒｉｎｖｅｒｓｉｏｎＬＩＳＨＥＮＧＸＵ（许力生）ＹＵＮＴＡＩＣＨＥＮ（陈运泰）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ...  相似文献   

相山火山—侵入杂岩Nd—Sr—Pb同位素地球化学特征   总被引：8，自引：6，他引：8  

范洪海  凌洪飞等 《岩石学报》2001,17(3):395-402

对相山火山－侵入杂岩Nd,Sr,Pb同位素组成及其底变质岩Pb同位素组成的研究表明，相山两旋回火山岩及火山期后的次火山岩具有较低的εNd(t)值（－7．46－9．40），较高的Isr值（0．70801－0．71201）和较古老的Nd模式年龄（1．54－1．70Ga)，且相对富集放射成因铅（^206Pb/^204Pb,^207Pb/^204Pb,^208Pb/^204Pb分别为17．686-18.323,15.523-15.730,38.143-38.936)。相山火山－侵入杂岩与该区出露的基底变质沉积岩在Nd,Pb同位素组成上既有明显的相似性，又有一定差别，因此，相山火山－侵入杂岩的源区主要为地壳岩石，但并不排除有部分幔源组分介入。ε  相似文献   

CONSERVATION OF MOIST POTENTIAL VORTICITY AND DOWN-SLIDING SLANTWISE VORTICITY DEVELOPMENT     

吴国雄  蔡雅萍  唐晓菁 《Acta Meteorologica Sinica》1996,(4)

An accurate form of the moist potential vorticity(MPV)equation was deduced from a completeset of primitive equations.It was shown that motion in a saturated atmosphere without diabatic heat-ing and friction conserves moist potential vorticity.This property was then used to investigate the de-velopment of vertical vorticity in moist baroclinic processes.Results show that in the framework ofmoist isentropic coordinate,vorticity development can result from reduction of convective stability,orconvergence,or latent heat release at isentropic surfaces.However,the application of the usual analy-sis of moist isentropic potential vorticity is limited due to the declination of moist isentropic surfaces.and a theory of development based on z-coordinate and p-coordinate was then proposed.According tothis theory,whether the atmosphere is moist-symmetrically stable or unstable,or convective stable orunstable,the reduction of convective stability,the increase of the vertical shear of horizontal wind ormoist baroclinity may result in the increase of vertical vorticity,so long as the moist isentropic surfaceis slantwise.The larger the declination of the moist isentropic surface,the more vigorous the develop-ment of vertical vorticity.In a region with a monsoon front to the north and the warm and moist airto the south,or by the north of the front,the moist isentropes are very steep.The is the region mostfavorable for development of vorticities and formation of torrential rain.For a case of persistent torrential rain occurring in the middle and lower reaches of theChangjiang and Huaihe Rivers in June 11-15,1991,moist potential vorticity analysis,especially theisobaric analysis of its vertical and horizontal components,i.e.MPV1 and MPV2,respectively,iseffective for identifying synoptic systems not only in middle and high latitudes,but also in low lati-tudes and in the lower troposphere.It can serve as a powerful tool for the diagnosis and prediction oftorrential rain.  相似文献   

Parameter　sensitivity　analyses　in　seismic　hazard     

王健  高孟潭 《地震学报(英文版)》1996,9(4):629-634

Ｐａｒａｍｅｔｅｒｓｅｎｓｉｔｉｖｉｔｙａｎａｌｙｓｅｓｉｎｓｅｉｓｍｉｃｈａｚ┐ａｒｄＪＩＡＮＷＡＮＧ（王健）ａｎｄＭＥＮＧ－ＴＡＮＧＡＯ（高孟潭）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅ...  相似文献   

Calculation　of　the　parameters　of　georesistivi－ty　anisotropy　and　case　history　of　earthquake　precursors   总被引：4，自引：0，他引：4  

钱复业  赵玉林  黄燕妮 《地震学报(英文版)》1996,9(4):617-627

Ｃａｌｃｕｌａｔｉｏｎｏｆｔｈｅｐａｒａｍｅｔｅｒｓｏｆｇｅｏｒｅｓｉｓｔｉｖｉ┐ｔｙａｎｉｓｏｔｒｏｐｙａｎｄｃａｓｅｈｉｓｔｏｒｙｏｆｅａｒｔｈｑｕａｋｅｐｒｅｃｕｒｓｏｒｓＦＵ－ＹＥＱＩＡＮ１）（钱复业），ＹＵ－ＬＩＮＺＨＡＯ１）（赵玉林）ａ...  相似文献