基于模态试验的机床结合部动刚度参数识别

Dynamic Stiffness Parameter Identification of Machine Tool Joint Based on Modal Test

机床结合部动力学辨识与建模方法一直是制约机床动力学研究和数字化设计的重要因素,为寻找一种比较理想的结合部动态参数识别法,以刀柄-刀具结合部为研究对象,采用完备频响函数的方法辨识机床结合部动力学参数。为验证方法的可行性,在准确建立研究对象有限元模型的基础上,将辨识的刚度参数通过弹簧阻尼单元代入模型中进行仿真分析,仿真与试验对比结果显示,刀柄组合件的前2阶固有频率误差分别为0.04%和0.013%,较小的误差率和一致的振型验证了方法的有效性。

The method of dynamic identification and modeling of machine tool joint has always been an important factor that restricts the study of machine tool dynamics and the digital design.In order to find an ideal dynamic parameter identification method for the joint part,taked the joint of a hilt as the research object,the dynamic parameters of the joint part of the machine tool were identified by the method of complete frequency response function.In order to verify the feasibility of the method,on the basis of established the finite element model of the research object accurately,the identified stiffness parameters were substituted into the model by spring damping unit for simulation analysis.The results of simulation and experiment show that the error of first 2 order natural frequency is 0.04% and 0.013% respectively.The small error rate and the uniform vibration mode verify the effectiveness of the method.