Study On Dynamic Response And Bearing Capacity Of Composite Foundation With Six Tube Piles For Offshore Wind Power

With the depletion of traditional energy and the aggravation of environmental pollution in the world,the development and utilization of new energy has attracted the attention of all countries around the world.Wind energy has become a hot research topic in the development of new energy in the world.The development and utilization of wind energy resources plays an important role in promoting the transformation and upgrading of energy structure,implementing the green new development concept and promoting the sustainable development of economy.Wind power generation is the fastest developing green energy technology.The main work and conclusions are as follows:(1)Based on Davenport spectrum,the wind speed time history curve is added by harmonic superposition,and then the time history curve of total wind load is calculated by empirical formula;the modified two parameter energy ITTC spectrum is selected,and the wave superposition method is used to obtain the wave force time history curve through Morrison equation;with the help of the formula in the code,the current velocity in the relevant sea area can be inferred by using the wind speed,and the time history curves of current force in different water depths can be obtained through further transformation.(2)Based on ABAQUS finite element software,the modal analysis results of the offshore fan six pile composite foundation structure are calculated.The conclusion is that the natural frequency and working frequency of the offshore fan are not in the same frequency range.It is concluded that the structure form will not cause resonance.(3)The results show that the response of the foundation is greater than that of the wave and current load,whether it is the stress or displacement response,but also the wind load,and the wave and current load play a major role in the dynamic response of the foundation,and it can be considered that the structure can also be considered as the wind load The resistance was strong.The dynamic analysis of wind,wave and current is studied.The dynamic response under the joint action is larger than that of the joint action.(4)Under horizontal load,the composite foundation of six piles in clay soil foundation turns around a point between the mud surface and the foundation,and the overturning and instability is damaged.The rotating center is aimed at this type of offshore wind power foundation in this paper,and it is located at the depth of 0.5L times of the buried depth of the cylinder under the mud surface.The rotation center position will change with the change of the structure size and load of the cylinder.The simulation results show that when the foundation enters the horizontal ultimate bearing state,the foundation has turned at a certain angle,the soil mass at the front side of the foundation is squeezed,resulting in vertical displacement,and the soil body at the back side of the foundation is close to the upper side and the barrel at the mud surface,which is in complete agreement with the failure mechanism and phenomenon in the actual engineering.