论文部分内容阅读
针对影响加工效率和加工表面质量的数控机床结构动态特性问题,提出一种新的实验模态分析方法.该方法以数控机床自身运动产生的振动为激励源,通过控制运动部件以特定方式空运行,激励起结构的有效振动响应,并结合基于响应信号的模态参数识别方法获得结构的动态特性参数.针对参数识别中的伪模态问题,综合运用识别结果预处理方法和模态稳定性原理,有效去除了识别结果中的伪模态,最终得到影响机床加工的3阶低频模态频率和阻尼比.所得结果与传统实验模态分析结果有较好的一致性.该方法可用于大型重型难激励数控机床的结构动态特性研究.
A new experimental modal analysis method is proposed for the dynamic characteristics of CNC machine tools which affect the machining efficiency and the machined surface quality.This method takes the vibration generated by the movement of CNC machine tool as the excitation source and controls the moving parts to empty in a specific way , The effective vibration response of the structure is stimulated and the dynamic characteristic parameters of the structure are obtained by combining with the modal parameter identification method based on the response signal.Aiming at the pseudo-modal problems in parameter identification, the preconditioning method and modal stability principle , The false mode in the recognition result is effectively removed and finally the third-order low-frequency modal frequency and damping ratio that affect the machining process are obtained.The results are in good agreement with the traditional experimental modal analysis.The method can be applied to large heavy-duty Research on Dynamic Characteristics of Hard Excited CNC Machine Tool.