中文摘要：

在复杂曲面多轴加工中,刀具可以在一定范围内以不同姿态加工复杂曲面,刀具姿态的改变直接影响整体加工系统的综合刚度特性,从而影响到加工性能。建立与刀具位姿相关的综合刚度场模型,可用于分析整体加工系统的综合刚性分布规律。提出多轴加工系统刚度场半解析计算方法,其中针对机床运动轴及其传动部位、刀具、工件等关键部件的力学特性分别采用了雅可比矩阵法、点传递矩阵法、有限元法等方法建立相应的刚度矩阵,并根据多体小变形理论建立了多轴加工工艺系统闭链刚度场模型。根据该模型解耦得到三维空间的力椭球,从力椭球提取整体加工系统的刚度性能指标,绘制刚度性能等值线图,分析工作空间中多轴加工系统的刚度特性分布规律,可用于指导刀具运动规划。

英文摘要：

During multi-axis machining process,complex surface can be machined flexibly while cutter＇s posture is changeable in available workspace,which directly affects general stiffness characteristics of multi-axis machining system and also machining performance.By establishing general stiffness model related to cutter posture,the distribution of stiffness performance of whole machining system is analyzed.Based on multi-body small deflection theory,a semi-analytic method about closed-loop stiffness modeling for multi-axis machining system is proposed,in which Jacobi matrix method,point transformation matrix method and finite element method are applied.The force ellipsoid corresponding to the decoupling stiffness model is established in 3D space.Stiffness index is derived from force ellipsoid,which is used to plot isolines of general stiffness performance of multi-axis machining system.The result of analysis about the distribution of stiffness performance can help direct tool motion planning.