Load Calculation And Fatigue Analysis Of Large-scale Horizontal Axis Wind Turbine Blades

With the development of high-power wind turbine, load calculations and fatigue lifeanalysis of the problem is more prominent. This chapter describes the wind turbine systemand the basic theory, including the theory and the blade element momentum theory, this paperbased on the structural characteristics of leaf blades established coordinate system.Accordingto the basic theory of wind turbine calculated gravity loads, aerodynamic loads andcentrifugal loads. Wind turbine life expectancy of20years. As the wind machine operates inworse environment, leaf withstand the combined effect of a variety of complex loads, it isprone to damage. Blade load calculation and fatigue life analysis is the development of windturbine blades and the failure to maintain the main reference content that can effectivelyimprove the reliability of wind turbine operation.This article uses the wind turbine computer modeling and simulation method, themethod of calculation of the load of the wind turbine,2MW wind turbine, for example,according to the IEC613400-1standard, developed a2MW horizontal axis wind turbine to runa variety of workingcondition. Bladed for Windows software, in the turbulent wind fieldsimulation leaves in a variety of static and dynamic load conditions, and found that the bladeroot load is the maximum load of the blade. I will do2MW wind turbine blade dynamicscalculations, including the simulation of normal operation, start, stop and emergency brake.Based software famose, rain flow counting method stress time histories frequency statistics.Blade load below the limit load cyclc stresss and higher than the limit load of randomstresss,but lower than the limit load of the cyclic stresss is the main reason for constituteingthe blade fatigue damage.Finally, based on the Weibull distribution function to determine the wind speeddistribution data, combined with the wind speed distribution percentage is the percentage ofstress cycles to determine the corresponding assumptions for each work cycle corresponds tothe percentage of stress, as well as selected S-N curve to determine the stress corresponding to each material recycling life, based on the use of wind turbine load spectrum and linearcumulative damage rule blade fatigue life calculation algorithm to calculate the wind turbineblade fatigue life and design life similar to that Miner linear damage rule based on a windturbine blade fatigue life calculation method is more practical calculation method.