Experimental-Analytical Substructure Model Sensitivity Analysis for Cutting Machine Chatter Prediction

摘要

Process reliability and dynamic stability is a growing customer demand in the metal machining industry. A limiting factor in process stability is regenerative vibrations which may damage the machined component, the cutting tool and even the machine tool. Spindle speed optimization to ensure process stability and enable larger cutting depths is based on the machine tool and cutting tool assembly's frequency response at the tool-tip. The traditional procedure to retrieve the tool-tip frequency response is to conduct dynamic testing of each machine tool mounted cutting tool. This methodology is normally very time-consuming. In an attempt to reduce testing time, receptance coupling substructure analysis (RCSA) has been proposed by a number of researchers. The objective with this approach is to measure the machine tool structure once and then couple a finite element based substructure representation of the cutting tool of interest. The accuracy of the predicted tool-tip frequency response is then dependent on the quality of measured data. This paper details the state-space based sub-structure coupling technique that is used and presents a sensitivity analysis. This analysis distinguishes key considerations for the machine tool component test and it quantifies the parameter influence on the process stability predictions of the coupled system.