用半理论法预测主轴系统刀尖点频响函数

Semi-theoretical Method for Prediction of Spindle System Tool Point Frequency Response Function

采用半理论法,即理论与试验相结合的方法预测主轴系统刀尖点频响函数。首先,介绍半理论法的预测原理;然后,应用半理论法预测主轴系统刀尖点频响函数的流程,包括利用梁理论计算自由-自由状态刀具两端的阻抗矩阵、搭建主轴-刀柄频响函数测试系统、测试装卡短光滑圆柱的主轴-刀柄系统的频响函数、根据半理论法计算刀尖点频响函数和试验验证;最后,以某立式加工中心主轴系统为研究对象,应用该方法对刀尖点频响函数进行预测,并与试验进行对比以证明该方法的有效性。

Spindle system tool point frequency response function(FRF) is an important indicator of NC machine tools which measures and evaluates the cutting stability.So obtaining the tool point FRF has great significance in effectively drawing up processing technology and evaluating the overall performance.The semitheoretical method,a combination of theoretical and experimental methods are adopted to predict the spindle system tool point FRF.Firstly,the prediction principle of semi-theoretical method is introduced.Then the process of applying this method in predicting FRF is researched,including calculating the receptance matrix at the free end of the tool by Timoshenko beam,setting up the test system of spindle-holder FRF,testing the FRF of spindle-holder system with the short cylinder,calculating tool point FRF by the semi-theoretical method and experiment validation.Finally,as a research object,the spindle system of a vertical machining center is used to predict the tool point FRF by the proposed method,then the effectivity can be verified by comparing with the experimental results.