Research On Coupled Vibration Of F2 Mill Drive System In 1580 Hot Strip Mill

The hot strip steel industry occupies a core position in the entire steel industry,and its national industrialization development level is determined by its production capacity.With the continuous advancement of the national strategy,the requirements for the quality and production efficiency of hot-rolled strip steel continue to increase.This paper aims at a certain steel enterprise 1580 hot strip mill when rolling high-strength thin-gauge strip steel,the F2 rolling mill transmission system vibrates abnormally and severely,the inlet strip steel fluctuates and other issues,through experimental research,the combination of theoretical and finite element analysis,as well as numerical simulation analysis methods,the coupling resonance mechanism of the transmission system is studied.The main research contents and results include the following aspects:(1)Through the comprehensive vibration test and signal analysis,it is found that the transmission system has multiple coupling resonance characteristics such as electromechanical coupling resonance and vertical torsional coupling resonance.And it is found that the thickness of the strip at the entrance of F2 rolling mill fluctuates and the vibration signals at each place have nonlinear harmonic phenomenon,and the transmission system shows overall resonance characteristics near multiple dominant frequencies of low-frequency torsional vibration.(2)In order to study the vibration problems and phenomena found in the actual measurement of the transmission system systematically,the equivalent model of shaftdisk quality of the drive system in F2 rolling mill is established,and the theoretical natural frequency characteristics of the drive system is solved,and three-dimensional model of the main drive system is established by SOLIDWORKS,and the finite element modal analysis is carried out by using ANSYS software,it is found that the overall resonance characteristics of the transmission system are close to the low-order mode shapes.By means of harmonic response method,the structural displacement response of the main drive system under electromechanical coupling resonance and vertical torsional coupling resonance is analyzed.It is found that when the excitation frequency of coupling resonance disturbance is close to the low-order torsional natural frequency of the transmission system,the structural resonance of the transmission shaft will be excited,and the overall resonance of the transmission system will be intensified.(3)In order to study the influence mechanism of the entrance strip thickness fluctuation on torsional vibration of transmission system in the F2 rolling mill,a dynamic rolling model under the entrance strip thickness fluctuation is established,and the dynamic load torque of the roll under the strip thickness fluctuation is theoretically analyzed,and the spring mass equivalent dynamic model and the nonlinear torsional vibration dynamic equation of the transmission system under load disturbance torque are rolling nalyzed,established.The main resonance amplitude-frequency response of the torsional vibration system under the load disturbance is obtained by the method of averages,and the main resonance response of the torsional vibration system under the change of parameters such as nonlinear stiffness and damping is numerically simulated.The results show that the torsional vibration of the transmission system can be effectively suppressed by reducing the load disturbance torque of the roll and the nonlinear damping coefficient.(4)Aiming at the multiple coupling resonance problems in the mill drive system,a nonlinear dynamic model of the torsional vibration system with multiple coupling resonance is established.The dynamic model is solved by the multi-scale method,and a wealth of non-primary resonance modes including 1/3 subharmonic resonance,3 times superharmonic resonance and sum-frequency combined resonance are obtained,and the amplitude-frequency response equations of various resonance modes are solved.Through the numerical simulation analysis,the nonlinear torsional vibration dynamic resonance response of the drive system under the action of coupling resonance is analyzed,it is found that the torsional vibration of the system can be alleviated and the stability of the system can be improved by adjusting various parameters properly,which provides theoretical support for the enterprise to adjust the process parameters and improve the rolling efficiency.