《船舶与海洋工程》2018/5
时间:2019/1/21 15:12:32Experimental Study on the Seismic Behavior of Grouted Connection of Offshore Wind Turbine Foundations
CHEN Tao1, ZHANG Chi-hai1, ZHAO Qi1, WANG Xian1, YUAN Guo-kai2, LIU Jin-chao2
(1.Department of Structural Engineering, Tongji University, Shanghai 200092, China;
2. China Energy Engineering Group Guangdong Electric Power Design Institute Co., Ltd., Guangzhou 510663, China)
Abstract: Offshore wind turbine in service may be subjected to seismic load, so it is necessary to analyze the hysteresis behavior of grouted connections with different axial compression ratios under low cyclic loading. An experiment was carried out on three grouted connection specimens with different axial compression ratios under cyclic load to study the failure patterns of the grouted connection specimens, in which seismic behaviors of hysteretic curves, energy dissipation, strength and stiffness degradation, as well as ductility of the specimens are analyzed. The result shows that the failure of the grouted connection accords with the level of grout fracture on the local buckling at the lower end of the outer tube. All grouted connection specimens exhibited favorable energy dissipation and ductility, even for the specimens under high axial load. The higher the axial compression increases, the lower the lateral ultimate strength of the grouted connection becomes. The ductility in displacement and the capacity of energy dissipation also decreases in such case.
Key words:offshore wind turbines; grouted connections; seismic behavior; axial compression ratio; ductility
Temperature Field Analysis for
Type C LNG Carrier’s Cargo Hold
JIANG Jun1, CHE Chi-dong1, LU Sheng2
(1. Shanghai Jiao Tong University, Shanghai 200240, China;
2. Shanghai Merchant Ship Design and Research Institute, Shanghai 201203, China)
Abstract: The cargo hold temperature field of type C Liquefied Natural Gas (LNG) carrier is often calculated with simplified one-dimension heat transfer method. It is hard to accurately determine the temperature distribution in the hull structures of cargo hold as the method is not so accurate, which often affects the selection of material for the cargo hold structures. This paper introduces the 3D finite element based temperature field calculation method for three types of heat transfer, i.e. heat conduction, heat convection and heat radiation, according to the heat transfer characteristics of type C LNG cargo hold. A 3000m3 type C LNG carrier is taken as the example to compare the calculation results under the extreme conditions respectively from the simplified method and the 3D finite element method. It is found that 3D finite element method can provide the temperature field variations of each region inside the cargo hold, which also provides the basis for accurate selection of structural material.
Key words:LNG carrier; temperature field; heat transfer; heat transfer coefficient
Development & Design of a Large-Cargo Carrier
with 130m Flat Deck
DONG En-chun
(New Century Ship Design & Research (Shanghai) Co., Ltd., Shanghai 201203, China)
Abstract: A large-cargo carrier with flat deck is developed and designed based on the characteristics of conventional cargo carriers and large ro-ro vessels as well as the special requirements of ship owner. Solutions dealing with the difficulties and key points in the design and development of the flat deck cargo carrier are presented in the paper.
Key words:deck cargo carrier; flat deck; large size cargo
Application of Finite Element Analysis on
Positioning Windlass Drum
GE Yang-yuan, MA Yun-jiao
(Nantong Liwei Machinery Co., Ltd., Nantong 226500, China)
Abstract: According to the situation that the traditional design methods are conservative and the mature theory for the strength design of thin-walled drum is not available, this study analyzes the load and deformation characteristics of large thin-walled welded drum, and creates a finite element model with the finite element analysis software ANSYS to calculate and analyze the loads on the positioning windlass drum under actual working conditions. Suggestions for the improvement of the traditional design are proposed based on the calculation. The result of finite element analysis shows that the improved design is able to reduce the thickness of drum’s wall properly without sacrificing safety and reliability. It is not only easy to manufacture and weld, but also meets the lightweight design requirement, and thus reduces the construction cost.
Key words:drum; finite element; ANSYS
Analysis on Airflow Distribution Plan of
the Meeting Room on a Polar Vessel
LIU Chun-jiang, XU Lian-si, HU Hao, Hua Cheng-xin
(Jiangnan Shipyard (Group) Co., Ltd., Shanghai 201913, China)
Abstract: This paper analyzes the airflow distributions in the meeting room of a polar multi-purpose containership under winter and summer working conditions. The fluid simulation and analysis software FloEFD is used in selecting a proper scheme. When the comparisons of the ventilation terminal schemes for the meeting room under winter working condition were carried out on the basis of thermal comfort improvement, the advantages of scheme B became visible in the qualitative analysis regarding the airflow distribution indexes such as temperature field, air age and velocity field. Then Scheme B was further analyzed with the simulations under the summer working condition, where the emphasis is laid on the air environment of the meeting room under polar environment. This study provides reference for the meeting room design of subsequent polar vessels built in China.
Key words:multi-purpose polar containership; meeting room; airflow distribution; simulation analysis
Numerical Simulation of the Torque on Three-Cylinder Fracturing Pump During Shale Gas Mining
LI Hong-hua,QU Yu-qiang,LIANG Yun,HU Sheng-deng
(SJS LTD, Sinopec Petroleum Engineering Machinery Co., Ltd., Jingzhou 424034, China)
Abstract: Fracturing pump is the key equipment for the shale gas mining with fracturing method, but at present, the pump mainly relies on import. In order to realize the independent development of the key equipment, this study analyzes the torque variation pattern of the pump by adopting the virtual prototyping technology in accordance with the characteristics of the pump such as the complex structures and the tedious design calculations. Numerical simulations of the torque on the three-cylinder pump are performed to obtain the torque variation curves and values, where the simulation model is created, the professional numerical simulation software is introduced and the conditions for connection, restriction, driving and excitation are added. The comparison with the analytical results validates the accuracy of the simulation result. It shows that the virtual prototyping simulation technology is not only suitable for the torque analysis of the fracturing pump but also suitable for the calculation analysis of other similar structures. It provides an important reference for the independent development, design and optimization of complicated pumps.
Key words:shale gas mining; fracturing pump; virtual prototyping numerical simulation technology
Application of Refrigeration and Liquefaction Technology
on LNG Carrier
XU Shuai,SHI Fang-le
(Hudong Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China)
Abstract: The Liquefied Natural Gas (LNG) inside cargo tank will be boiled off due to sloshing and the ingress of external heat during transportation, and thus lead to the reduction of cargo amount. In order to meet the IGC requirements on cargo pressure control, it is necessary to use some special equipment to eliminate the boiled-off-gas (BOG), but this will inevitably cause the loss of cargo. The most common method at the moment is to use refrigeration and liquefaction technologies to liquefy BOG and sent it back to the cargo tank, in this way to keep the cargo unlost. This paper mainly introduces the performance of the nitrogen expansion refrigeration and liquefaction technology, the hybrid refrigeration and liquefaction technology, and the direct refrigeration and liquefaction technology, makes some brief comparison and analysis on these technologies, and elaborates some of the practical applications.
Key words:refrigeration and liquefaction; nitrogen expansion refrigeration; hybrid refrigeration; direct refrigeration
Retrofit Design of Shore Power System for a Bulk Carrier
SHI Bin-jie,LIU Zhong-yin,LAN Feng,LIU Yun
(Shanghai Marine Diesel Engine Research Institute, Shanghai 201108, China)
Abstract: Taking the shore power system of a bulk carrier as the example, this paper analyzes the retrofit of adding two cable management systems and their shore power access cabinet. The high voltage connection method is adopted when the factors such as the target ship, the shore equipment, the power capacity and the functional requirements are considered. Of which the shore power capacity is 650kV·A and the shore cable is 50m in length. According to the analysis, the retrofit will keep an unsatisfactory result until the oil price goes up in the future. The NOx, SOx and PM10 emission of the target ship can be respectively reduced by 0.202t, 0.123t and 0.0084t in one day, which plays an important role in improving the environment of the port and even the city, and thus produces good social benefits. Besides, shore power supply can eliminate the noise pollution and vibration caused by operating of the ship’s auxiliary engines.
Key words:bulk carrier; shore power system; retrofit
Application of Closed Loop Power Supply Technology
on Offshore Facilities
CHEN Xi-yuan, LI Bing, WANG Zhong, WANG Yan-long, HE Zhi
(Dalian Shipbuilding Industry Design and Research Institute, Dalian 116000, China)
Abstract: This paper mainly introduces recently developed power system automation technology - the closed loop power supply technology. The advantages and requirements of closed loop power supply technology onboard ship/offshore platform are analyzed in accordance with the basic working principles and the requirements of DNV-GL rules. Then the guiding theory for design, debugging and testing of closed loop power supply is proposed on this basis, and thus to reach the goal of test verification and approved certification.
Key words:switchboard; closed loop; open loop; electric generator; generator protection system; hidden failure; failure analysis
Power System Design of the 20000TEU Container Ship
ZHOU Yi-long,FU Xiao-hong, XIA Jun, LIU Yuan, CHEN Tao,CHEN Jun-jie
(Marine Design & Research Institute of China, Shanghai 200011, China)
Abstract: This paper introduces the principles of voltage choosing from both the technical and economic aspects according to the characteristics of the medium voltage power system and the configuration of the power station capacity of a 20000TEU Very Large Container Ship (VLCS). It explains in detail the structure of the medium voltage power system on the 20000TEU VLCS, the control function of power manage system, the method of neutral-point grounding protection and the function of relay protection system. A scheme of regional distribution power supply and crossed power supply for the low voltage power system is proposed in accordance with the “twin islands” structure of the VLCS. It also analyzes the future developing trend of medium voltage power system for VLCS, which will be a reference for the future design of electric power system of VLCS.
Key words:medium voltage power system; neutral-point grounding protection; low voltage power distribution system; crossed power supply
Optimized Design for Base Installation Diagram of
Ship Ground Electrical Equipment
YAN Fan,ZHANG Yan-qin,TIAN Jing-qi
(Hudong Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China)
Abstract: To solve the problems encountered in the installation of ship ground electrical equipment, this study uses 3D modelling software SPD to implement model design optimization. When new base installation diagram drawing method is applied to the real ship, scrap and rework in the ground electrical equipment installation is effectively reduced or avoided, and the accuracy of the base diagrams, installation diagrams and opening diagrams are improved. This study provides reference for drawing of the based installation diagrams regarding new products and series products.
Key words:electrical equipment base; 3D model of electrical equipment; interference checking; base installation diagram drawing
Application of Orthogonal Design in LNG Cargo
Tank Invar Welding
ZHANG Jin-lin1, ZHU Han-feng2
(1. College of Marine, Ocean and Architecture Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China)
Abstract: The orthogonal design method of applied mathematical statistics is adopted to perform the analysis and calculation of different combinations of influencing factors on the invar end strake welding operation of Liquefied Natural Gas (LNG) vessel enclosure system such as the operators, assigned work load and equipment, in order to select the combination with highest efficiency and lowest defect rate, which will be the basis of on-site welding work arrangement.
Key words:LNG vessel; orthogonal design; invar end strake; welding defect rate
Cutting Process for the Ultra-Thick Rack of Jack-Up Leg
FENG Xiao-dong1,WANG Wei-yu2,MA Xiang-qian1,
LI Hu-qing2,JIA Bao-chun1,ZHANG Yong-jie2
(1. Zhengzhou TSC Offshore Equipment Co., Ltd., Zhengzhou 450000, China;
2. Dalian Shipbuilding Industry offshore Co., Ltd., Dalian 116000, China)
Abstract: This paper introduces the cutting process of the 210mm ultra-thick leg rack of the jack-up drilling platform (Type III) and the factors affect the process. The solutions to overcome the difficulties in ultra-thick rack manufacture are proposed, and a set of specifications for flame cutting of the ultra-thick rack are worked out with experiments, which is then applied to the manufacture of the required 210mm ultra-thick rack, and in this way to keep the project running smoothly.
Key words:ultra-thick rack; process of flame cutting; jack-up platform
Optimization of Container Ship’s Lashing and
Related Structure Precision Control
FENG Min-chao1,SHAO Dan1,CHEN Feng2
(Shanghai Waigaoqiao Shipbuilding Co., Ltd., Shanghai 200137, China)
Abstract: This paper introduces the aim and process of containership lashing experiment, analyzes the precision constraints of lashing experiment on the lashing bridge, the hatch coaming and its accessories, the hatch cover and other components. The outfitting precision control plan of the lashings and related structures is put forward, and numerical simulation of the lashing experiment is performed, which reduces the lashing experiment period, improves the management efficiency, and ensures the successful accomplishment of the lashing experiment.
Key words:container ship; lashing experiment; construction control
Analysis of Ropax Collision Based on GISISDatabase
LI Ruo-xi1 , TANG Wen-yong1, ZHANG Dao-kun2
(1. State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Technology Research & Development Center, China Classification Society, Beijing 100007, China)
Abstract: Marine accidents from 2003 to 2017 are analyzed based on the Global Integrated Shipping Information System (GISIS) of the International Maritime Organization (IMO), and an improved analysis method is proposed to solve the problems of lack of reasonable premise and lack of accident cause analysis for the report of formal safety assessment (EMSA project) submitted by the European Union to IMO concerning the Ropax damage stability. The causes for Ropax collision are analyzed according to the accident data report in the GISIS database, which is treated as the basic incident to establish a Ropax collision cause analysis model with the fault tree method. This study calculated the minimum cut set, carried out the sensitivity analysis, and measured the importance of various dangerous scenarios that may cause collision, then obtained the sequence of dangerous scenes and proposed the measures to control risk, which provides references for reducing the potential collision risk of Ropax ships.
Key words:Formal Safety Assessment; fault tree; marine collision accident; GISIS database
Research of Circular Spline Interpolation Based
on 3D Experience Platform
WANG Yao,ZHU Yu, LI Hai-bo,SUN Hao-yue,ZHU Ming-hua
(Jiangnan Research Institute, Jiangnan Shipyard Co., Ltd., Shanghai 201913, China)
Abstract: To solve the problem of precision deterioration in the jacking blanking of the 3D experience platform due to curve format conversions, this study proposes a curve spline interpolation method with multiple iterations according to the curve definition of the 3D experience platform. The programming of the automatic curve interpolation has been achieved based on the secondary development interface of the 3D experience platform. The interpolation result is recreated in the 3D experience platform for comparison, and the effectiveness of the method is validated through numerical experiments.
Key words:3D experience platform; circular spline; interpolation