Evaluation of a novel approach for considering damping effects in a process force model of a geometric physically-based milling simulation

Abstract

Process damping in milling is a significant influencing factor in avoiding detrimental dynamic effects such as regenerative chatter vibrations, which can impair the workpiece quality and increase tool wear. In this context, the use of tools with flank face chamfers causes significant process damping effects over a wide range of spindle speeds. This way, processes with increased material removal rates due to high radial and axial tool immersions can be conducted without the occurrence of disturbing chatter vibrations. A precise prediction of the process stability is necessary to define efficient process strategies in advance. However, this is particularly challenging in the presence of process damping due to its nonlinear process behavior. This paper presents an evaluation of a new approach towards modeling dynamic forces in a geometric physically-based milling simulation for taking process damping effects caused by chamfered cutting tools into account. This model considers the vibration velocity present at the cutting edge in order to calculate a damping force caused by the dynamic tool-workpiece contact. The parameterization of the velocity-dependent force model was carried out a priori by conducting finite element simulations using an orthogonal cutting model as an analogy setup to determine the resulting force components. The proposed modeling approach was analyzed by comparing the simulation results to corresponding milling processes for validation. In contrast to established empirical force models, which calculate the process forces entirely as a function of the undeformed chip shape, the consideration of the dynamic tool-workpiece interaction led to a significant damping of the modeled process vibrations.