Strength And Reliability Research Of East China Sea Continental Shelf Jacket Platform

For the jacket platform of the East China Sea,the waves and currents are the dominant load of offshore platform design,and severe waves and currents directly threaten the security of the platform.Research shows that the jacket platform is subjected to the load of the ocean simultaneously,the resonance phenomena can happen,so it is necessary to study the dynamic characteristics and reliability of the platform.In this paper,the natural vibration characteristics of the East China Sea continental shelf jacket platform,strength of platform,reliability and optimization under the ocean load force are systematically analyzed and researched by means of theoretical guidance,numerical simulation,engineering analysis,optimization software development and so on.The main research contents of this thesis are as follows:(1)Based on the East China Sea environment monitoring information,the marine environmental load parameters of jacket platform in the area were determined.For the target jacket platform,finite element model of the East China Sea continental shelf jacket platform was established with CAE technology.(2)On the basis of numerical simulation,the maximum stress variation of the jacket platform with the change of the incident angle of wave and current was researched respectively by means of the equivalent pile and considering pile-soil interaction,then the maximum equivalent stress of the platform was obtained,and the strength of the platform satisfied the strength requirements by the strength check.;At the same time,the modal analysis and dynamic response analysis were carried out for the jacket platform,the main vibration mode of the jacket platform and the dynamic response rules of stress and displacement of key position were obtained.(3)Based on the reliability theory,reliability analysis model of jacket platform was established.With the Monte Carlo method and Latin Hypercube Sampling technology,a random samping of wave and current parameters and design parameters was made,on the basis of the finite element analysis,the failure probability of the platform and the key parameters affecting the reliability of the platform were obtained,and then the reliability analysis of jacket platform was completed.(4)On the basis of reliability analysis,the dynamic optimization analysis of jacket platform was carried out,optimized component size,wall thickness distribution and so on,determined the main design parameters of the jacket,and then got the jacket structure of economic security;Based on Visual Studio platform,the optimization design software of jacket platform structure had been developed with the help of Visual Basic language.