An accurate description of the machine tool dynamics is essential in machining process simulation, chatter avoidance, and model-based monitoring. However, the standard practice of experimental modal analysis of an idle machine tool does not always provide an accurate representation of its dynamics under operating conditions. This paper proposes a modified transmissibility function-based operational modal analysis (TOMA) that assumes consistent mode shape for the spindle assembly to monitor the changes in natural frequency and damping ratio of the spindle. The transmissibility function-based solution considers only the relative vibrations between two sensors mounted on the spindle housing while the machine is excited by the cutting forces during machining. Experimental application of the Mode Shape Compensated TOMA was successfully demonstrated in multiple milling tests.

在加工过程仿真，避免抖动和基于模型的监视中，准确描述机床动力学至关重要。但是，对闲置机床进行实验模态分析的标准做法并不总是能准确表示其在运行条件下的动态。本文提出了一种改进的基于传递函数的运行模态分析（TOMA），该模态假设主轴组件采用一致的模式形状，以监视主轴的固有频率和阻尼比的变化。基于透射率函数的解决方案仅考虑了安装在主轴箱上的两个传感器之间的相对振动，而机床在加工过程中受到切削力的激励。