FE-CutS - Finite Elemente Modell für makroskopische Zerspanprozesse : Modellierung, Anaylse und Simulation
|Other Titles:||FE-CutS - Finite element model for macroscopic machining operations : Modeling, analysis and simulation||Authors:||Niebuhr, Carsten||Supervisor:||Schmidt, Alfred||1. Expert:||Schmidt, Alfred||2. Expert:||Piotrowska-Kurczewski, Iwona||Abstract:||
The resulting complex thermal and mechanical load pectrum in dry machining processes leads to temperature induced shape deviations of metallic orkpieces which changes its behavior for future use. Research projects try to compensate for manufacturing inaccuracies, resulting from the process, during the planning phase by using simulation-supported methods. The finite element method (FEM) is an appropriate tool to calculate thermomechanical behavior of workpieces by applying thermal and mechanical loads. This thesis describes the modeling and simulation of the thermal and mechanical behavior of workpieces considering material removal during the processes by FEM. In this case the FEM is linked to a dexel model to visualize the geometry change also in the FEM. During the mathematical modeling the heat equation is coupled to the quasi-stationary linear-elastic deformation equation on a time-dependent domain with changing boundaries. Heat fluxes and process forces are given from a process model and exist only during the tool-workpiece-interaction. These informations are project to the time-dependent bounds of the workpiece. Here a new visualization of material removal on unfitted meshes is presented. The mesh is divided into two time-dependent disjoint parts. One for the time-dependent workpiece and one for the removed material. The geometry of the workpiece is approximated on time changing bounds by adjusted adaptive methods. The analysis shows good results for the approximation with a controllable volume error. On thus time-dependent domain the thermal and mechanical workpiece behavior during machining processes could be simulated in a realistic case. During the processes the identification and compensation of shape deviations will be possible. The model can be extended for other processes with geometrically defined edges.
|Keywords:||FEM, milling, drilling, time-dependent domain, changing boundary, thermomechanical workpiece behavoir||Issue Date:||18-Sep-2017||Type:||Dissertation||URN:||urn:nbn:de:gbv:46-00106089-12||Institution:||Universität Bremen||Faculty:||FB3 Mathematik/Informatik|
|Appears in Collections:||Dissertationen|
checked on Jan 25, 2021
checked on Jan 25, 2021
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