Effect of workpiece vibration on dynamic cutting force in thin-walled plates trimming

In trimming of long overhanging thin-walled plates, we observed that the cutting force along the tool axis can be bidirectional rather than unidirectional like milling of short and stiff overhanging plates. This experimental phenomenon cannot be explained by standard oblique cutting force models. Accordingly, this study systematically investigated the interaction mechanism between the tool and the workpiece during trimming. It turned out that vibration velocity and displacement of the workpiece have non-ignorable effects on the direction of cutting velocity, engagement position between tool and workpiece, resulting in state-dependent inclination angle, instantaneous rotation angle and time delay. Consequently, a dynamic cutting force model that incorporates workpiece vibration-based modulation effects was developed, which effectively captured the change in the direction of cutting force along the tool axis. Furthermore, both simulation and experimental results demonstrated that workpiece vibration can reduce the amplitude of cutting force compared to rigid trimming. Additionally, surface comparisons of the workpieces after trimming were conducted, showing no obvious difference between short and long overhanging workpieces. This indicated that long overhanging thin-walled workpieces can be a feasible choice for trimming under certain conditions. These new findings offer new insights for trimming of thin-walled structures in industry.