Study on dynamic characteristics of the coupling system of flip-flow screen panel and material group based on FEM-DEM

Aiming at the problems of material group accumulation and large stress on the screen surface in the process of large deflection elastic screening of wet fine-grained minerals. Multi-ball excitation combined with elastic screening technology is proposed,exploring the dynamic characteristics of the coupling system of flip-flow screen panel and material group under the function of excitation ball in the screening process. The kinematic simulation model of screen panel under no-load condition is established based on the finite element method,and the kinematic characteristics of the screen panel is analyzed. The coupling technology of finite element and discrete element is used to explore the influence of material group on the kinematic characteristics of the screen panel. The simulation model of the coupling system between the screen panel and the material group under the function of the excitation ball is proposed,and the dynamic characteristics of the screen panel and the material group under the function of different excitation balls are analyzed. The orthogonal test scheme of four factors and four levels is designed,and the range analysis and variance analysis are used to study the significance of the influence of the number of material particles,amplitude, frequency and the number of exciting balls on the motion state and mechanical characteristics of the elastic screen panel. The optimal combination of the screen panel factors under heavy load conditions is determined,and its accuracy is verified. Results show that the characteristics of the material group on the screen panel have a great impact on the screen panel's amplitude,and the material on the screen will accumulate when the amplitude of the screen surface decreases to a certain extent. Using multi-ball excites screen panel,the overall displacement of the screen surface increases,the stress at both ends of the screen panel decreases,the screen panel with loaded material group changes from quasi-periodic motion to aperiodic chaotic motion, and the composition of fundamental frequency amplitude is more complex,which is conducive to the activity of material movement on the screen panel. The results of orthogonal test and response optimization show that the excitation ball and material mass are the significant factors affecting the kinematic and mechanical characteristics of the elastic screen panel,and when the amplitude of the screen surface is 4 mm,the frequency is 8 Hz,and the number of excitation balls is 3,the flip-flow screen panel in the screening process not only has a large displacement,but also receives a small force.