| Deep sea semi submersible production platform is an important support for offshore oil and gas mining.Because the platform is working at sea for a long time,it is subjected to wind,wave and flow and other alternating loads.Its structural strength is an important foundation and prerequisite for the good operation of the platform.Therefore,the fatigue strength analysis and risk point screening of the platform structure are carried out at the design stage.The effective detection of hot spots is very important for ensuring the safe operation of semi submersible platforms.In this paper,the structural strength and fatigue of semi submersible platform are studied as follows:(1)According to the production processing requirements of the target deep-sea semi submersible production platform and the related sea work specifications,the process of crude oil,natural gas treatment system,natural gas compression system and other auxiliary production systems was designed and the process rationality was verified by Aspen Hysys,and the weight of the process equipment was calculated according to the pressure vessel specification and so on.The overall weight of the module system in the upper part of the platform.(2)On the basis of establishing the hydrodynamic model and the structure model respectively,the AQWA hydrodynamic analysis software is used to calculate the motion response transfer function of the whole structure of the semi submersible platform on six degrees of freedom.The basic parameters of the design wave of the semi submersible platform are obtained by calculation and comparison of the wave load shear and bending moment,and the AQWA-WAVE will be used.The wave load is transferred to the structural model,and the stress cloud map of the platform structure is calculated.(3)The advantages and disadvantages of the fatigue analysis methods of different platform structures are analyzed.Using the S-N curve method,the Miner fatigue cumulative damage principle and the simplified fatigue analysis method based on the Weibull function distribution,and combining the C# programming language and writing software on the.NET platform,the APDL command flow encapsulation is realized,and the design of the platform is realized.Structural fatigue analysis and risk area screening are carried out at the stage.(4)Combining the fatigue crack propagation theory and the related results of fatigue analysis,the fatigue crack is analyzed and calculated with a certain representative finite element,and the fatigue crack failure parameters of the characteristic points are obtained,and the method of detecting the platform structure according to the crack failure is designed by combining the fuzzy comprehensive evaluation method.The possibility of the application of the fatigue analysis engineering is illustrated. |
PDF Full Text Request