Study On Dynamics And Noise Prediction Method Of High Speed Traction Elevator

Supported by the Scientific and Technical Plan of Zhejiang Province(No.2006C11251), "Development of the Key Technology of High Speed and Good Comfort Traction Elevators and Its Industrialization",the dynamic model and analysis methods of high speed traction elevators and its noise prediction and factor analysis,are studied systematically in this dissertation by combining theoretical analysis,numerical simulation with experimental verification.In Chapter 1,the background and significance of the research were introduced,the development trend and current research situations of the dynamics and acoustics of traction elevators were expatiated,and the research contents of this dissertation were proposed.In Chapter 2,a time-varying element model of the hoist cable-car system was proposed by modeling the system as a moving elastic string with a mass-spring-damper unit attached at the bottom which represents the elevator car.According to the Lagrange method,the horizontal nonlinear dynamic equation with time-varying parameters for high speed traction elevator was derived.Utilizing the fifth order polynomial fitted movement profile as the input,the vibration response of a high speed traction elevator case was calculated based on the precise integration method.Results demonstrate the validity of the time-varying element model and the solution.In Chapter 3,based on the approximate treatment of the contact relationship between the guide roller and rail,the expressions of the contact stiffness in normal direction and tangential direction were derived according to the Hertz's elastical contact theory and Kalker's linear creep theory respectively.The irregularity excitation due to the roller's roundness tolerance and the rail's unevenness was fitted.Then the dynamic equations of the guide rollers were constructed.In Chapter 4,the immediate integration - interface displacement synthetic method which is applied to analyze the complex system was represented.Based on the time-varying element model of the hoist cable and the contact model of the guide roller,the high speed traction elevator system was divided into several substructures and their governing equations expressed in the immediate integration format were derived.Then the dynamic equation of the whole system was assembled and solved according to the interface compatibility conditions.And the calculation result was compared with the experimental result.In Chapter 5,the modeling methodology of the elevator car and the guide rail was discussed.The dynamical interaction model of the high speed traction elevator car - rail system was established including the contact mechanism of the guide roller and vail,In this model,the guide rollers were modeled separately,and the gnide rail was modeled as a continuous elastical Euler beam with discrete supports.The interaction model was verified by comparing the simulation results with the experimental results.In Chapter 6,the Statistical Energy Analysis(SEA) method was investigated systematically.Then the modal density,interior loss factor,coupling loss factor and power input of each subsystem of the high speed traction elevator car were acquired by theoretical calculation and measurement.And the SEA model for predicting the noise in the high speed traction elevator car was built.The validity test has manifested the reliability of the SEA model.In Chapter 7,utilizing the SEA model of high speed traction elevator car,the noise in the elevator car due to the power input from the guide roller vibration and the noise from the machine room was compared.And the acoustic response in the elevator car was predicted with different running speed and guide rail irregularity.Then the acoustic contribution of each subsystem was contrasted.Based on the sensitivity analysis,the SEA parameters of the subsystems which affect the sound pressure of the elevator car the most sensitively were determined.At last,the effects of the mainly sensitive subsystems on the interior acoustic environment of the elevator car were simulated.Also detailed conclusions and suggestions were presented.In Chapter 8,the chief work and innovations of this dissertation were summarized,and the further research subjects were proposed.