Abstract: It is the highlight in machine tool chatter study area that the tool tip dynamic compliance must be well derived so that machining center cutting stability can be efficiently assessed by plotting the Stability Lobe Diagram (SLD).Impact testing was a simple and direct approach to acquire the dynamic compliance resulting to low working efficiency,which had to be repeated for different tools.Conventional sub-structure synthesis methodology could be borrowed to predict the tool tip dynamic compliance,however recptances concerning on rotational DOFs were extremely complicated either to calculate numerically or to acquire experimentally during the process.Thus a novel approach was described for quickly and accurately predicting machining center tool tip dynamic compliance while different tools were clamped.Methodology of Receptance Coupling Substructure Analysis (RCSA) was modified to deduce the equation of tool tip dynamic compliance.By combining Simulated Annealing (SA) and Particle Swarm Optimization (PSO),the equivalent dynamic coefficients of tool-holder joint were successfully identified,which was the critical foundation for target of prediction in the following section with another help of modified RCSA.The proposed approach was applied for predicting a given vertical machining center tool tip dynamic compliance.Experimental results and comparisons with prediction were provided to verify both validity and accuracy of proposed approach based on the high agreement.

Key words: machining center, tool point, dynamic compliance, receptance coupling substruture analysis, Simulated annealing and particle swarm optimization algorithm

摘要： 绘制极限切削深度叶瓣图可以对加工中心切削稳定性进行有效评价,其前提是必须事先获取机床刀尖点动柔度,这已成为近年来机床切削颤振领域的研究热点。采用锤击模态实验获取动柔度,手段虽然简单直接,但需面向不同刀具重复实验,效率很低;常规子结构综合法虽然可以预测刀尖点动柔度,但涉及转角相关柔度的计算繁琐且精度有限。为解决上述问题,提出一种可以快速、准确预测不同刀具装夹时加工中心刀尖点动柔度的方法。该方法的核心在于首先利用改进子结构柔度耦合分析法推导出刀尖点动柔度计算表达式,然后借助模拟退火粒子群算法辨识出刀具—刀柄结合部等效动力学参数,在此基础上再次基于改进子结构柔度耦合法求得刀尖点动柔度。以某立式加工中心为研究对象,应用所提方法预测机床刀尖点动柔度,并与实测值进行对比分析,结果显示二者符合程度较高,从而验证了所提方法的有效性和准确性。

关键词: 加工中心, 刀尖点, 动柔度, 子结构柔度耦合分析法, 模拟退火粒子群算法