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Andreas_Fellmeth

M.Sc. Andreas Fellmeth

Akad. Mitarbeiter
Bereich: Fertigungs- und Werkstofftechnik
Sprechstunden: nach Vereinbarung
Raum: 601.7, Geb. 10.50
Tel.: +49 721 608-46316
Fax: +49 721 608-45004
Andreas FellmethEth2∂kit edu

76131 Karlsruhe
Kaiserstraße 12


M.Sc. Andreas Fellmeth

Aufgaben und Forschungsgebiete:

  • Simulation des Verzugspotentials dünnwandiger, eigenspannungsbehafteter Bauteile beim Teilprozess Zerspanung
  • WGP-Produktionsakademie
     

Veröffentlichungen

[ 1 ] Zanger, F.; Fellmeth, A.; Gerstenmeyer, M. & Schulze, V. (2015), „Influence of Kinematic Hardening during Machining of ARMCO Iron“. Procedia CIRP, Hrsg. Schulze, V., S. 106-111.
Abstract:
The simpler implementation of isotropic hardening begs the question, if modelling kinematic hardening is necessary, especially if the hardening is nonlinear and temperature dependent. This question not only depends on the material, but also on the modelled load case, which varies with different manufacturing processes. To answer this, thermo-mechanically coupled elasto-plastic materials were used in an implicit material model in ABAQUS/Standard for a two-dimensional cutting simulation. The nonlinear hardening in the models varies from isotropic to mixed isotropic-kinematic hardening. The two-dimensional cutting simulation uses a two-dimensional continuous remeshing technique. A slow machining process was simulated leaving out strain rate and temperature dependencies and focussing purely on the kinematics of deformation. The necessity of a kinematically translated yield surface is concluded for iron, by comparing the purely isotropic to the mixed isotropic-kinematic hardening results. A comparison with experimental data illustrates the conformance quality of the different hardening modes.

[ 2 ] Imbrogno, S.; Segebade, E.; Fellmeth, A.; Gerstenmeyer, M.; Zanger, F.; Schulze, V. & Umbrello, D. (2017), „Microstructural and hardness changes in aluminum alloy Al-7075: Correlating machining and equal channel angular pressing“. AIP Converence Proceedings 1896, Hrsg. American Institute of Physics, S. 1-6.
Abstract:
Recently, the study and understanding of surface integrity of various materials after machining is becoming one of the interpretative keys to quantify a product´s quality and life cycle performance. The possibility to provide fundamental details about the mechanical response and the behavior of the affected material layers caused by thermo-mechanical loads resulting from machining operations can help the designer to produce parts with superior quality. The aim of this work is to study the experimental outcomes obtained from orthogonal cutting tests and a Severe Plastic Deformation (SPD) process known as Equal Channel Angular Pressing (ECAP) in order to find possible links regarding induced microstructural and hardness changes between machined surface layer and SPD-bulk material for Al7075. This scientific Investigation aims to establish the basis for an innovative method to study and quantify metallurgical phenomena that occur beneath the machined surface of bulk material.

[ 3 ] Fellmeth, A.; Zanger, F. & Schulze, V. (2017), „Kinematic Hardening of AISI 5120 During Machining Operations“. Procedia Cirp 58, Hrsg. Elsevier, S., S. 104-109.
Abstract:
Metal manufacturing processes like machining include complicated load cases and significant plastic deformation inside the manufactured component. The Finite-Element-Method (FEM) has been successfully applied to analyze machining processes. The plastic deformations during machining operations, especially of ductile materials, are a major part of the total deformation. If the deformation incorporates a large plastic deformation part with changing spatial directions, kinematic hardening should be considered, additionally to isotropic hardening. Previous work on the kinematic hardening of ARMCO iron revealed an almost near constant ratio of isotropic and kinematic hardening. The constant kinematic hardening ratio is revised and analyzed in tensile-compression tests with normalized AISI 5120. The FEM simulation results using the new material model of the kinematically hardening AISI 5120 are validated with experimental force measurement during orthogonal machining. The influence of kinematic hardening during machining operations is not the major influence, but still substantial.