Study On Fatigue Performance Of Floating Process And Supply Base Typical Structure

"Floating Process and Supply Base"as a new type of marine structure that is still in the conceptual design stage.It is the Offshore operations support equipment special equipment which is the marine engineering equipment and high-tech ships proposed in"Made in China2025".The equipment has a shallow draft,wide shape,and is moored in the distant sea for long periods of time under the influence of wave loads in a complex environment.One of the common and important forms of damage in the structural problems of ships and marine engineering is fatigue.As a new type of marine structure,FPSB is a valuable target for the study of its fatigue problem.Based on the above background,this paper uses the FPSB as a basis to conduct hydrodynamic analysis,overall strength calculation and fatigue research.The main research contents include the following four aspects:（1）By comparing the fracture mechanics,the nominal stress simplification calculation,the hot spot stress simplification calculation and the spectrum analysis method,spectrum analysis methods have been determined which used in this paper;the spectrum analysis method has been summarized as a new type of marine structure.Summarizes the advantages of spectral analysis methods which to study fatigue properties of new marine structures.The spectrum analysis methods of ABS,BV and CCS were compared in this paper.（2）Based on the 3D potential theory,the hydrodynamic analysis of FPSB was carried out in this paper.The FPSB’s motion and its profile load transfer function were obtained in this paper.A long-term forecast of the FPSB was carried out,and the long-term forecast value at 10^-8 probability level at zero speed and the distribution of wave load along the length of the FPSB were obtained.Comparing the simplified load calculation method and the long-term forecasting method in the guideline of fatigue strength of CCS hull structure,the load was obtained.（3）According to the long-term forecast results of load control parameters,the most dangerous wave that FPSB may encounter is selected based on the design wave method.Using the PCL language programming to apply this wave load to the ship’s finite element model,the stress and displacement distribution of the hull was obtained under the action of the design wave.Hot spots of the FPSB Fatigue Performance Study below are screened.（4）Based on the frequency domain spectrum analysis method,the fatigue strength of the FPSB was calculated based on the long-term data of the global wave load spectrum.Study and analyze the fatigue damage at different calibration locations.The influence of hotspot setting direction and wave propagation function on fatigue damage was studied.The distribution of fatigue damage on short-term sea conditions was studied.The distribution of fatigue damage on the sense wave height,zero-crossing cycle and wave direction was obtained.