Probabilistic Analysis Of Load Effect And Foundation Reliability For Wind Turbine Steel Tower Structure

With the rapid development of wind energy in recent years,more and more wind turbines have been built,and the supporting structure tower of wind turbines and foundation of wind turbines are the important guarantee for the normal operation of wind turbines.However,accidents involving the destruction of wind turbines have occurred frequently in recent years.One kind of damage is that the wind turbine tower was broken;the other is that the foundation of wind turbine was uprooted.According to the destruction phenomena,a series of studies were carried out on in this paper.on the one hand,ABAQUS software is used to simulate static analysis,modal analysis and dynamic analysis on a large tower of wind turbine.On the other hand,Monte Carlo method is used to the reliability analysis of the wind turbine foundation slab and the foundation ring,and its main work is as follows:(1)Taking a large wind turbine as an example in this paper,firstly,the force of the wind turbine tower is simplified,and start the static analysis of the wind turbine tower under the simplified load,then the distribution of stress and displacement of the wind turbine tower during two kind of wind speed conditions are obtained.comparing the difference between the second-order effect displacement and the internal force under two working conditions,which proves that the second-order effect of the tower is not obvious under different wind speed conditions.Through the theoretical calculation of the tower of wind turbine’s of the displacement and stress,its results and the analysis results are within the scope of permissible error of ABAQUS,verify the rationality of the modeling method(2)Through the modal analysis,obtained the blower tower’s natural frequency before six order natural frequency and vibration mode diagram,known tower’s adjacent two order natural frequency and vibration model figure can be regarded as one mode.Afterwards by time history analysis,obtained the dynamic response speed time history under the condition of two kinds of wind,shows the maximal displacement,bending moment and shear force at the bottom of the tower drum have a larger range of fluctuation,but normal wind conditions are in the scope of the safety of the tower drum,and the extreme wind speed conditions is likely to destroy,and record the wind load and Aerodynamic thrust duration in average coefficient and coefficient of variation of structural response.(3)On the other hand,This paper focus on the reliability of the wind turbine foundation,takes the dynamic response of wind load to the structure,overburden volume,concrete volume and strength as random variables,and converts the random variables of non-normal distribution into normal ones by method of equivalent normalization.Through sampling by Monte Carlo method,the unopened area of fan foundation slab and the reliability index of fan foundation ring anchor are obtained,which provides some references for the design of fan foundation in actual engineering.