非线性磨削中颤振抑制的研究

Research of chatter suppression in nonlinear grinding

在磨削加工过程中,颤振的发生通常使得工件表面出现振纹,严重降低工件的表面质量,而且加剧机床的磨损,缩短砂轮的使用寿命,因此,抑制磨削加工中的颤振具有重要意义。通过将Duffing振子考虑为砂轮的结构非线性项,建立了2自由度非线性磨削动力学模型。首先,采用数值仿真的方法,做出了磨削系统的稳态图和分岔图,研究了磨削工艺参数对磨削稳定性的影响;之后,为了抑制磨削颤振,采用主动控制策略来降低系统的振幅,仿真结果表明,主动控制策略很好地抑制了颤振,从而极大地提高了磨削工件的表面质量。

In the grinding operation,the chatter mark is often found in the surface of workpiece due to the occurrence of chatter vibration,which is harmful to the surface quality of workpiece and increases the wear of machine tool and shortens the life of the grinding wheel.So that it is of great significance to suppress the chatter vibration in the grinding process.In this paper,a two degrees-of-freedom nonlinear dynamic model is established based on the nonlinear structural stiffness of the grindstone.First of all,using the method of numerical simulation,the stable chart and bifurcation diagram are plotted to investigate the effect of grinding parameters on the stability in grinding.Thereafter,the active control is used to decrease the amplitude of vibration for the chatter suppression in grinding process.The results show that the active control has a good performance in the chatter suppression,improving remarkably the surface finish of workpiece.