| As countries around the world continue to increase the development of the ocean efforts,the importance of ocean platform in the field of ocean engineering is increasing.Due to the complex configurations of offshore platforms and the diversity of loads,the strength assessment of offshore platforms is an important guarantee for their structural safety.In this paper,the complex configuration offshore platform with complete structure is taken as the research object,and its structural load response,yield strength and structural ultimate bearing capacity under the combined load of wind and wave are analyzed and studied.The calculation results are summarized finally.The main research contents and conclusions include:(1)The environmental load research of the complex configuration platform was carried out.Combined with the characteristics of the structure itself,the wind load and wave load responses under extreme conditions were analyzed respectively according to the requirements of the specifications and the 3D linear hydrodynamic method,and the specific parameters of dangerous conditions were determined.The yield strength of the complex configuration platform under three limit conditions was checked,the dangerous structure of the platform was determined according to the calculation results,and the stress distribution mode under extreme conditions was analyzed.(2)Technical research was carried out for the ultimate bearing capacity calculation of complex configuration platform,and the influence of different calculations on the calculation accuracy was comparatively studied.The ultimate bearing capacity of the monolithic platform structure in nondestructive state under three ultimate conditions(transverse bending moment,longitudinal bending moment and torque)was studied by using quasi-static method,and the corresponding ultimate bearing capacity values of different failure modes were obtained.The progressive failure behavior and stress distribution of the structure under different conditions were analyzed.(3)The ultimate bearing capacity calculation method of complex configuration platform under the action of complex load was proposed,and the influence of different combinations of bending-torsion load on the bearing capacity was analyzed.The ultimate bearing capacity,progressive failure behavior and failure mode of complex configuration platform under the combined action of transverse bending moment,longitudinal bending moment and torque were studied.Based on the value of the ultimate bearing capacity,the formula describing the safety zone of the ultimate bearing capacity of the structure under the action of compound load was improved,and the practical application was discussed.The load response of complex configuration platform is analyzed with uncertainty analysis in this paper.The weak spots and main failure modes of the complex configuration platform are studied,and the ultimate bearing capacity of the platform under single load and compound load is analyzed.A set of evaluation and analysis process of the ultimate bearing capacity of the research platform under the action of composite load is formed.The research result has certain significance for the structure design and reliability check of the platform. |
