Structural Strength Analysis And Optimization Design Of Large Living Area For A Deep-water Semi-submersible Drilling Platform

The deepwater semi-submersible drilling platform is important equipment for deep sea oil and gas exploration and development.The guarantee of structural safety is the basic premise for its normal operation under the harsh sea conditions and complex loads.The research on the optimization design of the large living area should be carried out on semi-submersible which can provide important protection for the platform security.In this paper,the large living area of a deepwater semi-submersible platform is taken as the research object.The stochastic design wave method is used to determine the wave load parameters,and the semi-submersible platform structure response analysis of the large living area is carried out to screen the typical load of the dominant large living area.And summarize the rules of the large living area's participation in the total strength of the platform.Aiming at the high stress area of the large living area,a variety of corner structure improvement schemes are designed to compare and demonstrate,and the design scheme is optimized by Neighborhood Cultivation Genetic Algorithm method.The above work can provide reference for the structural design optimization of the semi-submersible platform in the future.The main research work is as follows:(1)The stochastic design wave method is used to determine the wave load parameters,and the typical load conditions of the structural strength of the large living area are studied.(2)The stress distribution of the large living area structure under different lateral and vertical layout positions was carried out,and the influence of the parameters such as the location and length of the living area on the total intensity of the participating platforms was evaluated.(3)For the stress concentration problem in the connection area between the living area and the platform deck,the angle type structure research was carried out,and the four corner structures such as the arc-shaped corner gusset,the elastic connection,the open stress relief hole on the bulkhead and the additional connecting bracket were respectively carried out.A comparative analysis was conducted to evaluate the effect of each program on the improvement of structural stress concentration in the living area.(4)Based on the Neighborhood Cultivation Genetic Algorithm method,the shape of the connecting bracket structure of the corner area of the platform is optimized.From the perspective of light weight and utilization of the bracket,a reasonable bracket design is obtained.The research work in this paper can provide a reference for the structural strength analysis,layout location selection and structural optimization design for the semi-submersible platform's large living area.