外圆磨削非线性动力学模型与实验验证

Nonlinear dynamics model of cylindrical grinding and experimental verification

  • 摘要: 磨削颤振是磨削过程中砂轮与工件之间产生的强烈振动,它的存在降低了被加工工件的表面质量,加速了砂轮磨损,因此研究磨削系统的稳定性是解决颤振现象发生的关键。首先依据外圆磨削动力学宏观结构建立非线性动力学微观模型,并推导出非线性动力学方程,利用Faddeev算法,对非线性动力学方程进行线性化处理计算出系统特征值,并进行稳定性预测,得出影响磨削稳定性的因素;然后以进给速度和砂轮长度为例使用Matlab绘制出各因素不同取值时的稳定区域图,并研究各参数在状态变化转折点所对应的时域响应图和特征值位置图,发现进给速度从10 mm/min提高到12 mm/min时磨削过程从不稳定转变为稳定状态,砂轮长度从12 mm增大到14 mm时磨削过程从稳定转变为不稳定状态;对稳定图、时域响应图和特征值位置图三者进行对比,发现得到的结论一致,证明模型的正确性。

     

    Abstract: Grinding chatter was a strong vibration between grinding wheel and workpiece, which reduced the surface quality of workpiece and accelerated grinding wheel wear. The key to solve the problem was improving the stability of grinding system. Firstly, the nonlinear dynamic model was established according to the dynamic macroscopic structure of cylindrical grinding, and the nonlinear dynamic equation was deduced, Faddeev algorithm was used to linearize the nonlinear dynamic equation to calculate the system characteristic values, and stability prediction was carried out to obtain the factors which affecting the system stability. Then, taking feed speed and grinding wheel length as an example, Matlab was used to draw the parametric stability chart with different values of each factor, and the time domain response chart and eigenvalue location chart corresponding to each parameter at the turning point of state change were studied, it was founded that the grinding process changed from unstable to stable when the feed speed increased from 10 mm/min to 12 mm/min, and the grinding process changed from stable to unstable when the length of the grinding wheel increased from 12 mm to 14 mm; parametric stability chart, time domain response chart and eigenvalue location chart were compared, and the conclusions obtained were consistent, which proves the correctness of the model finally.

     

/

返回文章
返回