Wang Yuhan

Structure Design of Large Blocks Lifting Tooling

Gantry crane is used frequently in the dock. How to reduce the number of lifting and improve construction efficiency are given more attention by shipyard. According to site and equipment conditions of a shipyard, a tooling which is used for the large blocks lifted is designed to improve construction efficiency. Moreover, the processes of lifting the large blocks are described. Tooling structure strength is checked by FEM. And the influence of different rails arrangement for tooling structure is analyzed. The successful tooling design plan is of great significance for improving construction efficiency, reducing building period and saving construction cost.Copyright

The Study on Hull Structure Strength Analysis and Opening Calculation of CJ46 Jack-Up Drilling Unit

The structural strength of jack-up units is the key issues in the design of ship and ocean engineering structures. Based on ABS MODU, the yield strength of CJ46 self-elevating drilling platform main hull structure is checked. Firstly, the environmental loads (wind, wave and flow) in three loading conditions which are required by specification are calculated by using GeniE (DNV). Then the 3D finite element model of main hull structure is established. The yield strength is checked and the results shown the large stress areas are leg well, jackcase which is connected with the leg and bulkhead which is main support structure under the cantilever sliding device, while the results meet the requirements of ABS MODU. Finally, the influence of the openings located in main longitudinal bulkheads are evaluated, meanwhile the main longitudinal bulkheads under skidding box need particular concern.Copyright

The Research on the Fatigue Analysis of the Jack-Up’s Leg Based on SESAM Software

In this paper, a fatigue assessment based on spectrum analysis for Jack-up’s legs is performed by adopting stochastic method for three water depths using DNV/SESAM. Firstly, force transfer function is determined by the DNV/WAJAC for each wave direction considered. Secondly, members end stresses are computed by the DNV/SESTRA. Then SCF (stress concentration factors), DAF (dynamic amplification factor) and P-delat effects are applied in the stress range calculations. Finally, the cumulative fatigue damage of unidirectional waves to the critical connections is determined by the DNV/FRAMEWORK. The critical connections at the chords and the braces are selected and reviewed for fatigue life calculation. The results show that the legs have fatigue lives exceeding the expected design life of Jack-Up Drilling Unit of twenty-five (25) years and meet ABS requirement.© 2015 ASME

The Effect on Hydrodynamic Performance of Multi-Point Moored FPSO in Swell Condition of West Africa

The paper respectively study the effect on hydrodynamic performances of FPSO under only swell and only wind-sea based on 3D potential theory and non-linear time domain coupled analysis method. The analysis results indicated that swell and wind-sea act as the same role in low frequency response. Swell is key factor in wave frequency response. Incident angle of swell evidently effects on mooring line tension. So it is necessary that we should consider swell and wind-sea at the same time in studying the hydrodynamic performances of FPSO in West Africa. The study offered an important reference on FPSO hydrodynamic performances analysis in West Africa.Copyright