Tool-workpiece interaction characteristics in micro-grinding BK7 glass considering nonlinear vibration

In micro-grinding, the improvement of machining accuracy has received increasing attention recently. However, the real-time dynamic change for taking into the grinding thickness during the machining process, combined with the complex vibration characteristics of the spindle, complicates the theoretical treatment. As a result, the role of interaction characteristics, particularly in the coupling relationship between the tool and workpiece, remains unclear. The coupled superposition algorithm for dynamic grinding force and vibration response is established to better understand the interaction between the tool and the workpiece. Considering the unbalanced excitation and nonlinear grinding force, a dynamic nonlinear model of the tool-workpiece in the grinding process is developed to predict the vibration response and dynamic characteristics during machining. According to the geometric relationship of adjacent abrasive grits during the machining process, the dynamic grinding thickness including the multi-degree of freedom instantaneous displacement is derived, and the dynamic grinding combined force on the primary and secondary surfaces of the tool is calculated. The accuracy of the dynamic model of microgrinding considering tool-workpiece interaction is verified based on the constructed microgrinding test bed. The effect of different dimensional parameters and operating parameters on the stability of spindle machining is analysed by the established model. The potential value of this research is to guide the selection of grinding parameters and the improvement of machining accuracy.