基于导纳综合法的立铣加工刀尖点动态特性预测

Prediction of Tool Point Dynamics of End Milling Processing System Using a Receptance Coupling Method

针对立铣加工系统中刀尖点动态特性理论预测的问题,研究了导纳综合法预测刀尖点位移导纳的方法.立铣加工系统被分为两个子系统,分割线位于刀具上.包含主轴的子系统结构复杂,不易精确建立动力学模型,因此采用试验方法获得其位移导纳.刀具子系统结构简单,采用有限元软件获得其位移导纳.两个子系统是具有不同截面的梁元件,二者通过单点结合,梁上节点具有平移和回转两个自由度.由两个子系统的位移导纳求出刀尖点的位移导纳.对上述方法进行了试验研究,以不同长度的45号钢棒为试验对象,获得了钢棒插入刀柄后的末端位移导纳.

The receptance coupling method for predicting tool point displacement receptance was studied to analytically predict tool point dynamical characteristics of end milling processing system.The processing system of end milling was divided into two subsystems with the parting line on the tool.The subsystem containing the main shaft is structurally complicated and hard to model analytically,so the displacement receptance was experimentally obtained,while that of the simple-structured tool subsystem was obtained using the finite element software.The two subsystems were beam units with different sections and connected by a single point.The nodes on the beam have translational and rotational DOFs.The displacement receptance of tool point was calculated based on displacement receptance of the two subsystems.Experiments were performed on 45# steel cylinders with different length,and the displacement receptance of the end point was obtained when the cylinders were assembled into holder.