机床切削颤振的非线性理论研究

由于机床结构结合面的动态特性常常表现为迟滞非线性特性,这种特性既包含了非线性刚度,又包含了非线性阻尼,因此,本文利用迟滞非线性建立了一个新的非线性颤振理论模型,利用等效线性化方法克服了解析分析上的困难,确定了该模型稳定性阈的近似解,获得了符合实际的三维稳定性图。通过对该稳定性图的分析,可以合理地分析及解释以往颤振理论所无法解释的种种颤振现象,例如颤振振幅稳定性现象、稳定性阈的分离现象、有限振幅不稳定性现象、微幅颤振现象以及双频颤振现象。

The Nonlinear Theoretic Research about Cutting Chatter of Machine tool

Because the dynamic property of joints in a machine tool appears to possess the hysteretic nonlinearitywhich contains not only nonlinear stiffness,but also nonlinear damping,a new nonlinear chatter theoreticmodel is established by considering this property in this paper.An equivalent linearization method is usedto obtain approximate resolve,so that a three dimension stability chart about cutting chatter is obtained.Many chatter phenomena,such as the amplitude stability,the separation of stability threshold,the finiteamplitude instability,the slight amplitude chatter and the chatter with double frequencies,can be analyzedand explained satisfactorily by this chart.