Project Details
Projekt
Compensation strategies for thermal effects in dry milling and drilling
Applicants
Professor Dr. Christof Büskens; Dr.-Ing. Jens Sölter
Subject Area
Metal-Cutting and Abrasive Manufacturing Engineering
Term
from 2010 to 2017
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 179077388
The objective of this cooperative project is the development of a new hybrid model and its implementation in an optimization algorithm in order to predictively minimize size and shape deviations in dry machining processes. The hybrid model consists of two sub models: In sub model 1 the effects of plastic deformations in the workpiece surface layer on bending and torsion of workpieces are described. Sub model 2 predicts deviations of the material removal due to thermo elastic strains during the machining process. Implementing the hybrid model in the optimization algorithm links the solving procedure of the partial differential equations directly to the optimization. The project partners expect a considerable speed up of the computation time compared to a separated optimization and solving procedure of the partial differential equations. However, it also leads to a high dimensional nonlinear optimization problem for which a sequential quadratic programming (SQP) algorithm implemented in the software WORHP will be applied. In the first two years of the priority programme the hybrid model was developed and parameterized for milling processes. Based on a validation the development of the hybrid model is currently extended taking into account more complex manufacturing tasks. In addition the computational efficiency of the model is increased by increasing the level of abstraction. The analyses focus on milling and drilling processes. In order to prepare the development of an optimization algorithm in the last two years of the priority programme the heat equation was implemented in WORHP and successfully validated. The implementation will be used for the parameter identification of the drilling process. Moreover sub model 2 of the hybrid model is currently implemented in WORHP. The objective of the last two years of this research project within the priority programme is to finalize the implementation of the hybrid model in WORHP and use it for the development of an optimization algorithm. The algorithm will be exemplarily applied for manufacturing tasks with increasing complexity. Two optimization scenarios will be addressed: the minimization of the machining time and the minimization of geometrical workpiece deviations. The predicted optimized manufacturing strategies will be validated by additional experiments. Finally the applicability of the hybrid model for other workpiece materials will be analyzed.
DFG Programme
Priority Programmes
