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| 1 | Reliability-Based Design for Jacket Platform Under Extreme Loads显示文摘In this paper, reliability analysis for the offshore jacket platform with the interaction of structure- pile- soil under extreme environmental loads is carried out. The inherent uncertainties of the environmental load, foundation soil, platform itself, and calculating models are evaluated. The action of extreme loads on the offshore platform is modeled as a function of extreme wave height. The system capacity of the whole platform is determined by nonlinear pushover analysis, and the relevant probability property is obtained by the simulation method. The reliability model for the whole jacket platform is described as the relationship between the load and resistance based on the offshore design codes. The reliability of whole platform is calculated by the analytical method and the importance sampling method on the basis of a case study for a tripod jacket platform. | Jin Weiliang Associate Professor, Dr. -Eng., Zhejiang University, Hangzhou 310027 | 1996 | China Ocean Engineering1996，11，2： | 17 |
| 2 | Analysis of Wave Loads on A Semi-Submersible Platform显示文摘For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design con-ditions are calculated by use of the three-dimensional boundary dement method. Methods for calculating the forward-speed free-surface Green function are discussed and a computer program with this Green function is developed. Accordingto the special rules, the wave loads under several typical design conditions of the platform are calculated. The maximumvertical bending moment, torsion moment and horizontal split force are determined from a series of contour maps of waveloads for the wave period of 5 to 18 seconds at a certain interval and the wave phase of O° to 360° at a certain interval.The wave height is determined by the function of wave period with a given exceedance probability. The maximum waveloads under the combination of wave parameters are used as the input of hydrodynamic pressure in the three-dimensionalfinite element analysis process. The transfer functions of wave loads on the platform are used for the fatigue strength anal-ysis of the K-tubular joint and the sub-model of the structure. | QIAN Kun(钱昆) WANG Yanying(王言英) | 2002 | China Ocean Engineering2002，17，3： | 12 |
| 3 | Seismic wave input method for three-dimensional soil-structure dynamic interaction analysis based on the substructure of artificial boundaries显示文摘The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves. | Liu Jingbo Tan Hui Bao Xin Wang Dongyang Li Shutao | 2019 | Earthquake Engineering and Engineering Vibration2019，18，4： | 11 |
| 4 | Dynamic Responses of Mobile Offshore Base Connectors显示文摘A Mobile Offshore Base (MOB) is a multi-purpose logistics base, which can be stationed in coastal or international waters. In the conceptual design of the MOB, attention should be paid to the dynamic responses of the inter-module connectors because tremendous loads occur in the connectors. In this paper, a study on dynamic responses of the MOB connectors is carried out by use of the Rigid Module Flexible Connector (RMFC) model which assumes that the module stiffness is significantly larger than that of the connector. In the analysis, the connector is modeled as a linear spring, which restricts relative translations but allows for relative rotations of modules. The 3-D source distribution method is adopted to determine the hydrodynamic forces of the modules, and the hydrodynamic interaction between modules is taken into account. The module motions and connector loads for 12 connector stiffness cases in regular and irregular waves are calculated with the multi-rigid-body motion equations. And the calculated results are compared with those from relative references. It is shown that the results obtained by different methods are in good agreement. | 余澜 李润培 舒志 | 2003 | China Ocean Engineering2003，18，4： | 8 |
| 5 | Calculation and characteristics analysis of blade pitch loads for large scale wind turbines显示文摘Based on the electric pitch system of large scale horizontal-axis wind turbines,the blade pitch loads coming mainly from centrifugal force,aerodynamic force and gravity are analyzed,and the calculation models for them are established in this paper.For illustration,a 1.2 MW wind turbine is introduced as a practical sample,and its blade pitch loads from centrifugal force,aerodynamic force and gravity are calculated and analyzed separately and synthetically.The research results showed that in the process of rotor rotating 360o,the fluctuation of blade pitch loads is similar to cosine curve when the rotor rotational speed,in-flow wind speed and pitch angle are constant.Furthermore,the amplitude of blade pitch load presents quite a difference at a different pitch angle.The ways of calculation for blade pitch loads are of the universality,and are helpful for further research of the individual pitch control system. | DAI JuChuan1,2,HU YanPing1,LIU DeShun1,2 & LONG Xin3 1 School of Electromechanical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China 2 College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China 3 Hara XEMC Windpower Co.,Ltd.,Xiangtan 411000,China | 2010 | Science China(Technological Sciences)2010，53，5： | 7 |
| 6 | A numerical simulation study on mechanical behaviour of coal with bedding planes under coupled static and dynamic load显示文摘To investigate the bedding influence on coal mechanical behaviour in underground environments such as coal or rock burst, simulations of dynamic SHPB tests of pre-stressed coal specimens with different bedding angles were carried out using a particle flow code 2-dimensional(PFC2D). Three impact velocities of 4, 8 and 12 m/s were selected to study dynamic behaviours of coal containing bedding planes under different dynamic loads. The simulation results showed that the existence of bedding planes leads to the degradation of the mechanical properties and their weakening effect significantly depends on the angle h between the bedding planes and load direction. With h increaseing from 0° to 90°, the strength first decreased and subsequently increased and specimens became most vulnerable when h was 30° or 45°.Five failure modes were observed in the specimens in the context of macro-cracks. Furthermore, energy characteristics combined with ultimate failure patterns revealed that maximum accumulated energy and failure intensity have a positive relation with the strength of specimen. When bedding planes were parallel or perpendicular to loading direction, specimens absorbed more energy and experienced more violent failure with increased number of cracks. In contrast, bedding planes with h of 30° or 45° reduced the specimens' ability of storing strain energy to the lowest with fewer cracks observed after failure. | Lihai Tan Ting Ren Xiaohan Yang Xueqiu He | 2018 | International Journal of Mining Science and Technology2018，28，5： | 7 |
| 7 | Influence of vertical loads on lateral response of pile foundations in sands and clays显示文摘Although the load applied to pile foundations is usually a combination of vertical and lateral components,there have been few investigations on the behavior of piles subjected to combined loadings.Those few studies led to inconsistent results with regard to the effects of vertical loads on the lateral response of piles.A series of three-dimensional(3D) finite differences analyses is conducted to evaluate the influence of vertical loads on the lateral performance of pile foundations.Three idealized sandy and clayey soil profiles are considered:a homogeneous soil layer,a layer with modulus proportional to depth,and two-layered strata.The pile material is modeled as linearly elastic,while the soil is idealized using the Mohr-Coulomb constitutive model with a non-associated flow rule.In order to confirm the findings of this study,soils in some cases are further modeled using more sophisticated models(i.e.CYsoil model for sandy soils and modified Cam-Clay(MCC) model for clayey soils).Numerical results showed that the lateral resistance of the piles does not appear to vary considerably with the vertical load in sandy soil especially at the loosest state.However,the presence of a vertical load on a pile embedded in homogeneous or inhomogeneous clay is detrimental to its lateral capacity,and it is unconservative to design piles in clays assuming that there is no interaction between vertical and lateral loads.Moreover,the current results indicate that the effect of vertical loads on the lateral response of piles embedded in twolayered strata depends on the characteristics of soil not only surrounding the piles but also located beneath their tips. | Lassaad Hazzar Mahmoud N.Hussien Mourad Karray | 2017 | Journal of Rock Mechanics and Geotechnical Engineering2017，9，2： | 7 |
| 8 | Stress-Strength Structural Reliability Model with a Stochastic Strength Aging Deterioration Process显示文摘A stress-strength structural reliability model was proposed with a stochastic strength aging deterioration process. In structural engineering,the deterioration of structure's strength should be the total of the deterioration owing to continual wear, fatigue,corrosion,etc.,and the abrupt deterioration as a result of randomly variable loads. The deterioration of structure's strength should be influenced by both the internal deterioration owing to direct wear and the external deterioration due to randomly variable loads.Meanwhile,the load process was given as Poisson square wave process. The reliability was derived using stress-strength interference theory. In particular,the reliability was also given when random variables followed the normal distribution. | 叶欢 陈庆华 | 2014 | Journal of Donghua University(English Edition)2014，31，6： | 5 |
| 9 | Optimal Load Balancing Leveling Method for Multi-leg Flexible Platforms显示文摘The working platforms supported with multiple extensible legs must be leveled before they come into operation.Although the supporting stiffness and reliability of the platform are improved with the increasing number of the supporting legs,the increased overdetermination of the multi-leg platform systems leads to leveling coupling problem among legs and virtual leg problem in which some of the supporting legs bear zero or quasi zero loads.These problems make it quite complex and time consuming to level such a multi-leg platform.Based on rigid body kinematics,an approximate equation is formulated to rapidly calculate the leg extension for leveling a rigid platform,then a proportional speed control strategy is proposed to reduce the unexpected platform distortion and leveling coupling between supporting legs.Taking both the load coupling between supporting legs and the elastic flexibility of the working platform into consideration,an optimal balancing legs' loads(OBLL) model is firstly put forward to deal with the traditional virtual leg problem.By taking advantage of the concept of supporting stiffness matrix,a coupling extension method(CEM) is developed to solve this OBLL problem for multi-leg flexible platform.At the end,with the concept of supporting stiffness matrix and static transmissibility matrix,an optimal load balancing leveling method is proposed to achieve geometric leveling and legs' loads balancing simultaneously.Three numerical examples are given out to illustrate the performance of proposed methods.This paper proposes a method which can effectively quantify all of the legs' extension at the same time,achieve geometric leveling and legs' loads balancing simultaneously.By using the proposed methods,the stability,precision and efficiency of auto-leveling control process can be improved. | GANG Xianyue CHAI Shan | 2013 | Chinese Journal of Mechanical Engineering2013，26，5： | 5 |
| 10 | Fundus manifestations and HIV viral loads of AIDS patients before and after HAART显示文摘AIM: To investigate the fundus manifestations and human immunodeficiency virus(HIV) viral loads of acquired immune deficiency syndrome(AIDS) patients before and after highly active antiretroviral therapy(HAART).METHODS: This retrospective study included 21 AIDS patients(42 eyes) who presented to the Department of Ophthalmology, Peking Union Medical College Hospital, from 2007 to 2011. Among the patients, 16 showed a good response to HAART, 3 presented drug resistance and 2 were pre-HAART. All patients underwent comprehensive ophthalmic examinations. The HIV viral loads and the CD4+ T-cell counts were also determined.RESULTS: The best-corrected visual acuity(BCVA) of 38 eyes(19 patients) was improved, and cytomegalovirus retinitis(CMVR) in 5 eyes(3 patients) regressed after HAART. Furthermore, 16 patients treated with effective HAART had decreased plasma HIV viral loads(<78 copies/mL)and increased CD4+ T-cell counts(343±161 cells/μL, P<0.005), but the HIV viral load in tears was still detected at 2404 copies/mL. The CD4+ T-cell count was lower in the CMVR group than in the non-CMVR group(P=0.022), but the HIV viral load in the tears was not significantly different between the two groups(P=0.439).CONCLUSION: Most patients with AIDS show a good viral response with a decreased HIV viral load and an increased CD4+ T-cell count in plasma after HAART. However, the HIV viral load remain quite high in the tear samples. Based on our results, we suggest that AIDS patients undergo long-term HAART that should not be interrupted. | Yu Di Xin-Yu Zhao Jun-Jie Ye Bing Li Nan Ma | 2019 | International Journal of Ophthalmology(English edition)2019，12，9： | 4 |
| 11 | 基于GIS的流域水质目标管理TMYL构架研究——以赣江流域为例显示文摘以赣江流域为例,提出了基于GIS的TMYL计划技术框架,构建了以保持水生态系统健康为目标的流域水质目标管理技术体系。在ARCGIS9.3的环境中,利用GIS的叠置技术,建立基于控制单元为管理核心、污染源在线监控为配套建设的三级监控体系。结合流域水污染防治绩效评估体系的建立及评估分析,为流域水污染控制的总量控制方案和对策措施提供辅助决策依据。实践表明,在水污染防治过程中,地理信息数据的统计分析是实现流域水质目标业务化管理的重要工具,为数据管理、空间图形表达和空间决策分析提供有效的工作平台和可靠的技术支持。以控制单元为管理核心的管理方式,是实现流域水生态健康可持续发展,流域水质长期满足水生态服务功能的重要手段。 | 谭斌 陈武权 谭广宇 李红华 曹茜 刘锐 | 2011 | 环境保护科学2011，37，6： | 3 |
| 12 | The joint long-term distribution of design environmental factors for offshore structures Multivariate probabilities and simulating method显示文摘With the development of ocean engineering, it is one of the most important factors which determine the structural safety, cost and suitable forms of engineerings to select the ocean environmental design criteria. Owing to the complexity , variation and randomness of ocean environmental conditions, the commonly used methods for determining design criteria cannot consider the joint occurring probabilities of several environmental factors ,therefore, lead to overestimate design criteria of them and result in an unnecessary overspend invest in engineering. On the basis of the measured and hindcasting data and the multi-demension joint probability theory, this paper presented the study of the joint loads of wind , wave and current on the offshore structures and its responsible joint probability level with the application of random simulation techniques, and presented the joint design criteria of environmental loads for the realistic design of engineerings. | Shi Jiangang, Liu Defu and Wang Zheng Department of Ocean Engineering and Naval Architecture, Tianjin University, Tianjin 300072, China | 1993 | Acta Oceanologica Sinica1993，12，3： | 3 |
| 13 | Stability Analysis of Bohai Oil-Drilling Ship No. 6 Under Static and Cyclic Loads显示文摘- This paper presents a procedure to calculate the safety factor against sliding of a marine gravity structure subjected to a combination of static and cyclic loads. This procedure claculates the stress at the sliding surface by the finite element method (FEM) and takes the dynamic properties of clay into account. With this procedure, the stability of a Bohai oil-drilling ship is analyzed. The calculated safety factor is much smaller than 1, indicating that this oil-drilling ship would fail just as what had happened to it. | Qiu Changlin Yan Shuwang Graduate student, Dept. of Hydraulic Engrg., Tianjin University . Professor, Dept. of Hydraulic Engrg., Tianjin University | 1996 | China Ocean Engineering1996，11，4： | 3 |
| 14 | Balance control of grid currents for UPQC under unbalanced loads based on matching-ratio compensation algorithm显示文摘In three-phase four-wire systems, unbalanced loads can cause grid currents to be unbalanced, and this may cause the neutral point potential on the grid side to shift. The neutral point potential shift will worsen the control precision as well as the performance of the threephase four-wire unified power quality conditioner(UPQC),and it also leads to unbalanced three-phase output voltage,even causing damage to electric equipment. To deal with unbalanced loads, this paper proposes a matching-ratio compensation algorithm(MCA) for the fundamental active component of load currents, and by employing this MCA,balanced three-phase grid currents can be realized under 100% unbalanced loads. The steady-state fluctuation and the transient drop of the DC bus voltage can also be restrained. This paper establishes the mathematical model of the UPQC, analyzes the mechanism of the DC bus voltage fluctuations, and elaborates the interaction between unbalanced grid currents and DC bus voltage fluctuations;two control strategies of UPQC under three-phase stationary coordinate based on the MCA are given, and finally, the feasibility and effectiveness of the proposed control strategy are verified by experiment results. | Xiaojun ZHAO Chunjiang ZHANG Xiuhui CHAI Jinlong ZHANG Fanqi LIU Zhe ZHANG | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，6： | 2 |
| 15 | Deformation properties of chloride saline soil under action of a low-temperature environment and different loads显示文摘To find the deformation properties of chloride saline soil under the influence of a low temperature environment and different loads,two types of chloride saline soil were selected and their deformation process was tested in the laboratory and analyzed during the cooling process in the sensitive cryogenic temperature range.The research results show that high-chloride-salt saline soil underwent little volume change under the no-load condition during the cooling process.Under staticload and dynamic-load conditions,different degrees of settlement deformation occurred;throughout the entire cooling process,another chloride saline soil with a high proportion of sulfate salt underwent volume expansion under no-load and static-load conditions.Under the no-load condition,a certain degree of settlement deformation occurred.Deformation properties were evaluated at different time points during the cooling process for two kinds of chloride saline soil.Finally,deformation characteristics of chloride saline soil were analyzed from the perspective of salt type and crystallization variation under the action of a low-temperature environment and different loads. | Yu Zhang Jian Kun Liu Jian Hong Fang An Hua Xu | 2017 | Research in Cold and Arid Regions2017，9，3： | 2 |
| 16 | Mean wind load induced incompatibility in nonlinear aeroelastic simulations of bridge spans显示文摘Mean wind response induced incompatibility and nonlinearity in bridge aerodynamics is discussed,where the mean wind and aeroelastic loads are applied simultaneously in time domain.A kind of incompatibility is found during the simultaneous simulation of the mean wind and aeroelastic loads,which leads to incorrect mean wind structural responses.It is found that the mathematic expectations (or Iimiting characteristics) of the aeroelastic models are fundamental to this kind of incompatibility.In this paper,two aeroelastic models are presented and discussed,one of indicial-function-denoted (IF-denoted) and another of rational-function-denoted (RF-denoted).It is shown that,in cases of low wind speeds,the IF-denoted model reflects correctly the mean wind load properties,and results in correct mean structural responses;in contrast,the RF-denoted model leads to incorrect mean responses due to its nonphysical mean properties.At very high wind speeds,however,even the IF-denoted model can lead to significant deviation from the correct response due to steady aerodynamic nonlinearity.To solve the incompatibility at high wind speeds,a methodology of subtraction of pseudo-steady effects from the aeroelastic model is put forward in this work.Finally,with the method presented,aeroelastic nonlinearity resulted from the mean wind response is investigated at both moderate and high wind speeds. | Zhitian ZHANG | 2019 | Frontiers of Structural and Civil Engineering2019，13，3： | 2 |
| 17 | Combined approach for analysing evolutionary power spectra of a track-soil system under moving random loads显示文摘The pseudo-excitation method combined with the integral transform method (PEM-ITM) is presented to investigate the ground vibration of a coupled track-soil system induced by moving random loads. Commonly in the track model, the rail, sleepers, rail pads, and ballast are modelled as an infinite Euler beam, discretely distributed masses, discretely distributed vertical springs, and a viscoelastic layer, respectively. The soil is regarded as a homogenous isotropic half-space coupled with the track using the boundary condition at the surface of the ground. By introducing a pseudo-excitation, the random vibration analysis of the coupled system is converted into a harmonic analysis. The analytical form of evolutionary power spectral density responses of the simplified coupled track-soil system under a random moving load is derived in the frequency/wavenumber domain by PEM-ITM. In the numerical examples, the effects of different parameters, such as the moving speed, the soil properties, and the coherence of moving loads, on the ground response are investigated. | Y.Zhao L.T.Si H.Ouyang | 2019 | Acta Mechanica Sinica2019，35，3： | 2 |
| 18 | Study on topographic compensation model of the Okinawa Trough I. Calculation of theoretical isostatic response function显示文摘Based on regional compensation and experimental isostasy, the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below. A variety of curves of theoretical isostatic response function were calculated with different effective elastic thickness of the plate and by using different proportions between loads on top and loads from below. And preliminary discussion is made on shapes of the curves. | Liu Baohua Wu Jinlong Xin Baisen and Peng Chao 1. First Institute of Oceanography, State Oceanic Administration, Qingdao 266003, China 2. Ocean University of Qingdao, Qingdao 266003, China (Received October 12, 1997 accepted July 17, 1998) | 1999 | Acta Oceanologica Sinica1999，18，2： | 2 |
| 19 | Study on topographic compensation model of the Okinawa Trough Ⅱ. Geological interpretation of isostatic response function of the Okinawa Trough显示文摘Based on regional compensation model and experimental isostasy, the isostatic response function of the Okinawa Trough is calculated by using gravity and topographic data. The results are shown as follows: the effective elastic thickness of the plate and compensation depth in the southern Okinawa Trough is obviously greater than those in the middle Okinawa Trough. In reference with other geological and geophysical data, the differences between the two portions are explained to be caused mainly by their differences in temperature of the lithosphere and the compensation mechanism. | Xin Baisen Liu Baohua and Xia Zhifeng 1. Ocean University of Qingdao, Qingdao 266003, China 2. First Institute of Oceanography, State Oceanic Administration, Qingdao 266003, China (Received October 12, 1997 accepted July 17, 1998) | 1999 | Acta Oceanologica Sinica1999，18，2： | 2 |
| 20 | Experimental investigation on single person's jumping load model显示文摘This paper presents a modified half-sine-squared load model of the jumping impulses for a single person. The model is based on a database of 22,921 experimentally measured single jumping load cycles from 100 test subjects. Threedimensional motion capture technology in conjunction with force plates was employed in the experiment to record jumping loads. The variation range and probability distribution of the controlling parameters for the load model such as the impact factor, jumping frequency and contact ratio, are discussed using the experimental data. Correlation relationships between the three parameters are investigated. The contact ratio and jumping frequency are identified as independent model parameters, and an empirical frequency-dependent function is derived for the impact factor. The feasibility of the proposed load model is established by comparing the simulated load curves with measured ones, and by comparing the acceleration responses of a single-degree-of-freedom system to the simulated and measured jumping loads. The results show that a realistic individual jumping load can be generated by the proposed method. This can then be used to assess the dynamic response of assembly structures. | Chen Jun Wang Haoqi Wang Ling | 2015 | Earthquake Engineering and Engineering Vibration2015，14，4： | 1 |
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