Papers by Author: Sven Grünert

Abstract: Different possible reasons for defects have to be considered in machining light-weight aluminum structures. In the machining process, the cutting power affecting the workpiece leads to a thermo-mechanical load that can cause undesirable workpiece deformations and thus shape deviations. Moreover, the microstructure and the machined surface can be influenced, which is detrimental to the later application of the structures. Previously conducted experimental and simulative investigations, estimated the circular milling process to be the most suitable machining operation that provides the best compromise between mechanical and thermal loads compared to drilling operations [1,2]. In this paper the results of machining end-cross-sections of an aluminum profile are presented. The machining was obtained by a milling process, which is demanding, because of the low profile stiffness. For this process it is important to know the effects of machining in view of the shape deviations. By means of a Finite-Element-Analysis the deformations of the profile web can be calculated as well as validated by experiments. Based on these results, the appropriate process parameter values for end machining can be defined.

Abstract: Most technical components applied in industrial practice are subjected to metal cutting operations during their production process. However, this leads to undesirable thermal and mechanical loads affecting the machined workpiece, which can result in an impairment of its serviceability. Due to their small wall thickness lightweight hollow profiles are highly susceptible to the inevitable machining loads and thermal stresses during drilling processes. For the virtual optimization of the machining process and in order to ensure a suitable process strategy, a finite element simulation of cutting operations for thin-walled light metal profiles is conducted. Due to the flexibility within creating drill holes of different diameters without tool changes circular milling represents a promising alternative to the application of conventional drilling tools for variable process strategies to handle batch sizes down to one piece efficiently. Hence, this article gives an insight into the investigations regarding the modeling concepts of the mechanical and thermal loads induced into the thin-walled lightweight frame structure during the circular milling process. Furthermore, process reliability aspects as well as the correlation of the calculated and the measured results will be discussed on the basis of experimental investigations. Finally, this article compares Finite Element Analysis aspects of circular milling processes with conventional drilling processes.