Finite Element Analysis Of Vibration Characteristics Of High Frequency Vibrating Screen

The vibrating screen is not only used in heavy industries such as coal,but also in the light industry such as pharmaceuticals and tobacco.In recent years,shaker screens in various industries have also become increasingly skilled in research,design and manufacturing.The quality of vibrating screens not only depends on the load that the structure can withstand,but also whether the screening efficiency is qualified.In the tobacco industry,due to its light screening material,the screen of the vibrating screen must meet the requirements of light and thin,but also to prevent the deformation of the screen plate with a large frequency of vibration.Therefore,the technical requirements for vibrating screens in the light industry such as tobacco are relatively high.In this paper,based on the double plastid high-frequency vibrating screen of Qinhuangdao Tobacco Machinery Factory,the characteristic parameters,structural strength and displacement response of the three-degree-of-freedom double-body vibrating screen were studied.The aim is to provide an optimal basis for the theoretical calculation of the high-frequency vibratory sieves for two-body and to optimize the parameters of the high-frequency vibratory sieves.The main content of this paper is to use the Lagrangian equation to obtain the differential equations of motion of the two-body high-frequency vibrating screen in the three-degree-of-freedom system.Using MATLAB to solve,calculate its third-order natural frequency,and analyze the influence of each parameter variable on the natural frequency in the structure.The two-body high-frequency vibrating screen is simplified as a basic model of shell element and beam element combination,and modeling and unit division are performed.Perform modal analysis on the structural model to obtain various frequency and vibrational cloud patterns.The harmonic response analysis was carried out on the model structure of high-frequency vibrating sieve girder with dual masses,and its steady-state displacement response under different frequency excitation force was obtained.Studying the vibration characteristics of the vibration motor start-up process shows that the exciting force and the angular frequency of the motor are a multiple power function according totime and gradually reach a steady state.List the single rotational differential equations of the vibration system,and then use the fourth-order Runge-Kutta method to solve the program,obtain the angular frequency function graph of the vibration motor with time as an independent variable,and obtain the function relationship of the excitation force and time.The excitation force at the time of starting the motor is applied as a function load on the model,and the transient dynamics analysis is performed on the high-frequency vibrating screen of the dual-body.Study the change of the amplitude of the upper and lower mass bodies with time,the resonance time point during the start-up process,and the stress distribution on the structure during resonance when the motor is turned on until the stable operation period.Through the above-mentioned process research,modal analysis shows that the high-frequency vibrating screen does not resonate at the normal working frequency;the harmonic response analysis shows that under the action of the given frequency of2 Hz and 6Hz,the vibration amplitude of the vibrating screen is Larger.The amplitude of the middle frame is 9.86 mm,the vibration amplitude of the upper screen body is17.06 mm.It can be seen from the stress cloud diagram of the structure that the stress is larger at the front end and the tail end of the screen surface,and attention should be paid to optimizing the structural strength of the screen surface;the transient dynamic analysis shows that In the motor start-up process,it has experienced three times of resonance.The stress concentration phenomenon is distributed at the front and the end of the screen surface and the spring assembly.This paper lays the foundation for structural dynamics analysis and optimization design of high-frequency vibrating screens for plate-girder.In the follow-up work,the amplitude of upper screen components can be optimized by increasing the number of shrapnel components;The best quality ratio to improve the screening efficiency of the vibrating screen;adjust the size of the screen surface and middle frame,and find the best design ratio under the premise of maintaining the maximum amount of material.