Optimization Design Of Lateral Traction Bracket For Wind Turbine Blade Static Loading

In order to verify that the wind turbine blades have the ability to withstand extreme loads,static loading tests on the blades are required.At present,static loading tests at home and abroad generally adopt the method of lateral traction and vertical pull-down.For the consideration of the test space,the indoor test platform mostly adopts the lateral traction mode.In recent years,as the blade size increases,the loading load of the static test gradually becomes larger,which puts higher requirements on the structural strength of the traction bracket.During the static loading test of different types of blades,the bracket pulleys will have obvious wear due to the contact with the wire rope for a long time.At the same time,due to the lack of the characteristic mechanical properties of the key components,the structure of the traction bracket is often relied on by experience.The main components that cause the load are bent,worn or wasted due to redundancy or lack of design.In order to solve this problem,the paper firstly studies the process of wire rope winding pulley in wind power blade static loading test,and then uses orthogonal test,dynamic simulation and finite element analysis to complete the structural optimization design of traction bracket.The specific research results are as follows:(1)Aiming at the serious wear between the bracket pulley and the wire rope,the evaluation index of the bearing stress on the surface of the pulley is proposed.Aiming at the wear problem of the wire rope and the pulley surface,the contact model of the two is established.The mathematical expression of the compressive stress on the surface of the pulley is derived by the micro-element analysis method and the Hertz contact theory.Based on the stress expression,the influence wire rope pulley is determined.The main factors of the wear problem,and analyzed the mechanism of action of each factor(2)According to the actual design requirements of the traction support test,combined with the mechanical design manual,the horizontal value of each influencing factor is selected,and the orthogonal test design is carried out to withstand the compressive stress on the surface of the pulley under the limit load condition.Several orthogonal test groups were obtained.The ADAMS/Cable module was used to simulate the dynamic winding simulation of the wire rope winding pulley.According to the specific requirements of the loading test,the drive,load and motion pair were added,and the simulation model was established.The reasonable simulation time and the number of steps were set up.The dynamics simulation of the wire rope winding process was carried out,and the contact between the wire rope and the pulley was obtained.(3)According to the dynamic simulation results of the process of wire rope winding pulleys,the tension attenuation trend of the wire rope during the simulation process is obtained,and compared with the theoretical attenuation trend,the accuracy of the dynamic simulation model and the rationality of the simulation results are verified.The dynamic simulation was carried out by the orthogonal test group.The test results were analyzed by the variance analysis method.The optimal structural parameters of the pulley were obtained,and the optimal design of the pulley structure was realized.(4)Based on the optimal structural parameters of the pulley,the dynamic simulation model of the traction bracket is established.The dynamics of the whole structure is simulated and the force state of each part is obtained.The parts are processed by the finite element analysis software ANSYS Workbench.According to the analysis of the solution results,the optimization of the structural dimensions of each part with light weight as the goal,and the static analysis of the optimized structure,verifying the rationality of the optimization scheme,and completing the overall optimized design of the structure.