Abstract

With the high G value of vibration, outstanding sieving behaviors of a flip-flow screen are more likely to appear, but structural damages are aggravated under the high amplitude vibration. Considering rubber springs role on the vibration energy dissipation, viscoelasticity of rubber springs (i.e., shear springs and vibration isolation springs), is noticed to deal with the above contradiction. However, when rubber springs experience large amplitude vibration, viscoelastic responses influence more on the amount of damping than in the linear (i.e., small amplitude) vibration regime, as the frequency dependence of rubber springs is noteworthy. For this purpose, the Generalized Maxwell model is used to depict the frequency dependence of rubber springs and the practical damping is converted to a series damping parameters of the system, numerical models of the flip-flow screen under startup and shutdown modes and steady working conditions are proposed and verified firstly. Secondly, in order to explore kinetics responses of the elastic screen panel under different rubber springs damping coefficients, nonlinear finite element model of which is established. Finally, effects of rubber springs nonlinear damping on screen frames vibrations and screen panels nonlinear responses are studied. Results indicate that hysteretic damping of rubber springs can effectively solve the conflict between vibration strength and structural reliability of the flip-flow screen, since the low sensitivities of maximum stresses and the high sensitivities of accelerations to rubber springs damping are found.

Highlights

  • Relying on the intense alternating load generated by the rotation of the vibration exciter and engaged reciprocating motions of the elastic screen surface, acceleration of a flip-flow screen is nearly 50 g, which makes difficult-to-filter coal easy pass through screen pores [1]

  • Under a certain excitation force, the dynamic characteristics of the screen body is regulated by vibration energy dissipation of rubber springs

  • Tang et al.: Viscoelasticity of Rubber Springs Affects Vibration Characteristics of a Flip-Flow Screen body are probed by solving vibration differential equations of the screen system, which are established based on the vibration theory [4], [5]

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Summary

INTRODUCTION

Relying on the intense alternating load generated by the rotation of the vibration exciter and engaged reciprocating motions of the elastic screen surface, acceleration of a flip-flow screen is nearly 50 g, which makes difficult-to-filter coal easy pass through screen pores [1]. J. Tang et al.: Viscoelasticity of Rubber Springs Affects Vibration Characteristics of a Flip-Flow Screen body are probed by solving vibration differential equations of the screen system, which are established based on the vibration theory [4], [5]. Researches above mainly focus on influences of self-parameters and installation characteristics of the screen surface, the mass of the screen body and excitation forces on dynamic responses of the screen panel, which neglect effects of rubber springs (including shear springs and vibration isolation springs) dynamic characteristics. Because of the importance of rubber springs nonlinearity, with the established nonlinear finite element model of the screen panel, independent and coupling effects of the shear spring and the vibration isolation spring are discussed in this paper

MODEL CONSTRUCTIONS
NONLINEAR FEM MODEL OF THE SCREEN PANEL
RESULTS AND DISCUSSION
RUBBER SPRINGS DAMPING EFFECTS ON RESPONSES OF THE SCREEN BODY
REGRESSION ANALYSIS OF DAMPING EFFECTS
CONCLUSION
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