The overall aim of the project/research was to develop finite element modelling/process simulation capability to predict workpiece surface integrity following machining of advanced aerospace alloys. The modelling work employed the general-purpose commercial finite element (FE) software ABAQUS, due to its robust solver for handling complex, dynamic non-linear problems as well as the facility to define custom algorithms/subroutines. Both 2D and 3D fully coupled thermo-mechanical FE models were formulated to simulate the orthogonal turning of Ti-6Al-4V titanium alloy and Inconel 718 nickel based superalloy. The performance of various material models and associated damage criteria were assessed, with high strain rate (up to ~ 6000 s\(^-\)\(^1\)) / temperature (up to ~ 850°C) flow stress data for Inconel 718 obtained from compression tests using SHPB and Gleeble systems. In addition to evaluating the influence of operating conditions on response measures such as cutting forces, temperatures and chip morphology, the FE models were extended to enable prediction of grain size distribution due to dynamic recrystallisation (DRX) of workpiece microstructure following machining. This was accomplished by developing a VUMAT user customised subroutine that included material constitutive modelling, damage initiation/propagation as well as a novel material model to predict workpiece grain refinement due to DRX.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:646208 |
| Date | January 2015 |
| Creators | Munoz, Raul E. |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/5844/ |
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