Vibration And Noise Analysis Of High-speed Traction Elevators

Elevator noise is low-frequency noise,which is very harmful to the human body.Reducing elevator noise has become an important issue to be solved urgently.The elevator noise is mainly composed of vibration noise and aerodynamic noise.The vibration of the elevator is divided into lateral vibration and longitudinal vibration.In this paper,the lateral vibration,longitudinal vibration and aerodynamic characteristics of the elevator are studied respectively,and the research results are used as sound source excitation for noise analysis.The main research content is divided into the following seven parts:(1)Establishing the transverse vibration dynamics model of the elevator,deducing the differential equation of the lateral vibration of the elevator,and establishing the mathematical model of the misalignment excitation,bending excitation,step excitation and overall superposition excitation of the guide rail respectively.And constructing the simulation system by using the Simulink module in Matlab.The model is simulated and its calculation results are used as the parameter basis for elevator noise simulation.(2)Establishing the longitudinal vibration dynamics model of the elevator,and establishing the ten-degree-of-freedom differential equation of the longitudinal vibration system of the elevator through the Lagrangian equation.Due to the time-varying characteristics of the steel rope,a time-varying model of the stiffness of the steel rope is established,and the simulation system model is built by AMESim software.The simulation analysis is carried out,and the calculation result is used as the parameter basis for the elevator noise simulation.(3)Through the fluid analysis software Fluent,the aerodynamic characteristics of the elevator are simulated and analyzed.The analysis results show that the aerodynamic drag of the car in the Z direction is much larger than the aerodynamic drag in the X and Y directions,which is the main source of the aerodynamic drag of the elevator.The absolute value of the aerodynamic drag in the z-direction of the second half of the car is slightly larger than the first half,which is caused by the different turbulence.The rolling moment and pitching moment of the car are much larger than the yaw moment,which is the main reason for the lateral vibration of the car.(4)Using the lateral and longitudinal vibration simulation results of the elevator as the noise source excitation,ANSYS is used to simulate the noise.The simulation results show that the lateral vibration of the elevator is the main cause of vibration and noise.The noise reduction method of the sound insulation wall is studied.The results show that the method reduces the elevator noise by 15.38%.Based on the Fluent software and FW-H equation,the aerodynamic noise of the elevator is simulated and analyzed.The simulation results show that the elevator aerodynamic noise is much smaller than the elevator vibration noise.(5)The method of opening the air outlet on the wall of the hoistway is used to reduce the aerodynamic noise of the elevator.The single factor experiment shows that the number of air outlets is two,which is the best to improve the aerodynamic characteristics of the elevator.If only one tuyere is opened,the car will be subjected to greater aerodynamic drag and torque.When the shape of the tuyere is circular,the improvement of the aerodynamic characteristics of the elevator is optimal.The optimal solution of a set of tuyere parameters is obtained by genetic algorithm optimization.Based on the parameters of the group of air outlets,the aerodynamic noise simulation analysis of the elevator is carried out,and the open air outlet test is carried out at the same time.The results show that the method has a great improvement on the aerodynamic characteristics of the elevator,but the noise reduction effect is not obvious.(6)The method of laying the sound absorbing layer around the wall of the hoistway is used to reduce the elevator noise.The thickness of the sound absorbing layer is studied by single factor simulation test.The thickness of the best sound absorbing layer is determined by polynomial fitting,and the noise simulation and experimental verification are carried out.It shows that the noise reduction effect of this method is not obvious.(7)The method of installing the vibration damping pad under the base of the traction machine is used to reduce the vibration and noise of the elevator.The longitudinal vibration of the car under different stiffness of the damping pad is simulated by AMESim,and the polynomial fitting is performed to establish the traction machine.The one-dimensional model of longitudinal vibration velocity,acceleration and stiffness of the damping pad is optimized by genetic algorithm to obtain the optimal damping pad stiffness value.Based on the stiffness value,the vibration and noise of the elevator after installing the damping pad are simulated and analyzed.The experimental results show that the method has a great reduction on the vibration and noise of the elevator.