Dynamic Analysis Of Friction Vibration Of Wind Turbine Disc Brake System

With the development of wind power technology,wind turbines have become a trend product on the market as the main use of wind energy.The disc brake is a key component of the wind turbine,which is an important guarantee for the safety and reliability of the wind turbine.Due to the complex force and torque of the wind turbine during the braking process,the brake will have different degrees of deformation,and the friction plates and the brake discs are not uniformly worn,and the two cannot be in good contact with each other,which may cause the occurrence of brake vibration and affect the braking performance of the wind turbines brake.Therefore,it is very important to study the frictional vibration of wind turbine.The main research work and results of this paper are as follows:Firstly,according to the actual operation of the wind turbine braking system and considering the contact coupling between the brake disc and the inner and outer friction plates,a six-degree-of-freedom dynamics simulation model for the brake disc-friction plate of the brake system was established and the vibration characteristics of the brake disc and the friction disc were analyzed.The results showed that the vibration amplitude of the friction plate in the initial stage of vibration was relatively large.With the time increasing,the system vibration tended to be stable.As the braking force increases,the amplitude of the brake disc and the friction plate increases,and the vibration increases.Compared with copper-based powder metallurgy materials and cast iron materials,C/C fiber composites have better performance.Therefore,under the action of the same braking force,the friction plates of C/C fiber composite materials had the least influence on the vibration of the system,with the lowest amplitude and the shortest time for the system to be stable.Secondly,the finite model of friction pair were established.The overall deformation of the friction pair during the braking process was analyzed.And the deformation curves of the brake disc and the friction piece on the specified path were obtained.The results showed that the maximum deformation of the brake friction pair occurred at the edge where the friction disc contacts the brake disc,and the minimum deformation occurred at the joint between the spindle and the brake disc.The deformation of the brake disc increased with the radius of the brake disc and the maximum deformation occurred at the edge of the disc.The deformation of the friction plate was increased along with the increase of the width.Finally,the modal analysis of the overall brake friction pair was performed based on the results of structural statics analysis,and the natural frequency and mode shape were obtained under both the deformation and non-consideration.The results showed that due to the symmetry of the brake structure,the vibration of the brake disc in both cases was symmetrically distributed along the circumference and the deformation of the friction disc was symmetrical.Compared with the two conditions,we can see that due to the existence of pre-stress,the stiffness of the brake changed,and the structure deformation also changed.This paper can provide theoretical and technical basis for the further study of friction vibration of wind turbine disc brakes,and lays a foundation for optimizing brake structure research and development of new types of brakes.