轧机, 振动, 时频分析, 混沌

The nonlinear dynamic model of rolling mill vertical vibration was established by introduction to Duffing oscillator and the parametrically excited stiffness. A cubic function hysteresis model of strip was choosen by contrasting the simulation and the measured results. From the simulation results, it shows that the roll amplitude appears bifurcated under certain conditions, and the vibration presents chaos. Through the time-frequency analysis of measured data, it shows that the value of vibration frequency and its spectrum have significant changes over time. And there are harmonic resonance or combination resonance. It also shows that the vertical vibration system has non-stationary and chaotic characteristics by correlation dimension and largest Lyapunov exponent calculation.