Development of Analytical Endmill Deflection and Dynamics Models

Accurate knowledge of machine dynamics is required for predicting stability and precision in a machining process. Frequency response function (FRF) measurements need to be performed to identify the dynamics of the systems experimentally. This can be very time consuming considering the number of tool-tool holder combinations in a production facility. In this paper, methods for modelling dynamics of milling tool is presented. Static and dynamic analysis of tools with different geometry and material are carried out by Finite Element Analysis (FEA). Some practical equations are developed to predict the static and dynamic properties of tools. Receptance coupling and substructuring analyses are used to combine the dynamics of individual component dynamics. In this analysis, experimental or analytic FRFs for the individual components are used to predict the final assembly’s dynamic response. The critical point in this analysis is to identify the interface stiffness and damping between the tool and tool holder. The effects of changes in tool parameters and clamping conditions are evaluated. The predictions are verified by measurements.