eTheses Repository

# Finite element modelling (including material grain refinement prediction) when turning advanced aerospace alloys

Munoz, Raul E. (2015)
Ph.D. thesis, University of Birmingham.

 Munoz15PhD[1].pdfPDF (14Mb)Accepted VersionRestricted to Repository staff only until 31 July 2018.

## Abstract

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.

Type of Work: Ph.D. thesis. Soo, Sein Leung and Aspinwall, David K. Colleges (2008 onwards) > College of Engineering & Physical Sciences School of Mechanical Engineering TJ Mechanical engineering and machinery University of Birmingham 5844
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.

Repository Staff Only: item control page