Optimization of milling process

Manufacturing of thin-walled aluminum components for e.g. the aviation industry challenges skilled CNC operators as process vibrations can cause both damaged components and unnecessary wear on the cutting tools.

By combining simulations, experiments and optimization methods, it is possible to determine process parameters that maximize productivity while keeping the process vibrations at acceptable levels. By combining Tech Invent’s skills in simulation tools, data collection, experimental work and mechanical understanding, it is possible to simplify advanced production processes to a level where we can efficiently and accurately maximize productivity by means of simulations.

The productivity of the milling process for the workpiece shown to the right was increased by more than 50%. Finite Element modeling was used to predict the properties of the flexible component while modeling of the milling process was handled with analytical models. The models were validated and updated using experimental and operational modal analysis (EMA, OMA). Stability and deflection during the milling process were monitored through measurement of sound, forces, accelerations and strains which were analyzed in the frequency domain and compared with simulations and the surfaces of the finished workpiece. Simulation of milling processes involves time-varying dynamics, nonlinear forces and instability. Therefore, general optimization methods cannot be used directly. Consequently, part of the task in this case was to select and develop strategies for formulating the optimization problem and then solving it. The optimization problem was formulated through inspiration from control theory, while solving the problem was handled through application of resampling and parallel computing. The work of combining the multiple computational tools, handling large amounts of experimental data, validating models and developing new optimization strategies requires a high degree of precision, thoroughness and documentation – all of which characterize how the engineers at Tech Invent operates.