考虑受辊系振动影响时轧制力的动态特性,建立了板带轧机辊系非线性振动模型。采用平均法求解得到振动系统的幅频响应,分析不同轧制速度和外激励幅值对幅频特性的影响规律。运用奇异性理论分析振动系统静态分岔行为,得到系统分岔的转迁集以及出现不同振动形态的临界条件。以轧制速度为分岔参数,研究轧机辊系振动系统动态分岔特性。结果表明:轧机辊系振动行为对轧制速度变化十分敏感,振动幅值随着外激励幅值和轧制速度增大而增大,系统不稳定频率范围随着轧制速度提高而减小,随外激励幅值增大而增大;系统随轧制速度变化出现阵发性混沌运动,结合最大Lyapunov指数曲线得到稳定轧制时的速度范围。研究结果为抑制轧机振动和保障轧机稳定运行提供了理论参考。
Considering the dynamic characteristics of the rolling force influenced by roller vibration,a nonlinear vibration model of strip mill roll system was established.Average method was adopted to get the amplitude frequency response of the vibration system,the amplitude frequency characteristics of the system were analyzed with the changing rolling speeds and external excitation amplitudes.The singularity theory was used to analyze the static bifurcation behavior,and to get the transition set and the critical conditions of different forms of vibration behavior of this system.The dynamic bifurcation behavior was researched with the changing rolling speeds.The results show that vibration behavior of rolling mill is very sensitive to the changing rolling speeds,the vibration amplitude increases with the increasing of excitation amplitudes and rolling speeds,the frequency range of instability decreases with the increasing of rolling speeds,increases with the increasing of external excitation.The intermittence chaos is appeared with the changing of rolling speeds,and the speed range of steadying rolling is obtained with the maximum Lyapunov exponent curve.The results provide a theoretical reference for the vibration suppression and guarantying stable operation for rolling.