@inproceedings{RauerKuehhornSpringmann, author = {Rauer, Georg and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Residual Stress Simulation of an Aero Engine Disc during Heat Treatment}, series = {Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), Vienna, Austria, September 10-14, 2012}, booktitle = {Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), Vienna, Austria, September 10-14, 2012}, publisher = {Techn. Univ.}, address = {Wien}, isbn = {978-3-9502481-9-7}, language = {en} } @inproceedings{RauerKuehhornSpringmann, author = {Rauer, Georg and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Residual Stress Modelling and Inverse Heat Transfer Coefficients Estimation of a Nickel-Based Superalloy Disc Forging}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 6, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25827}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 6, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25827}, publisher = {ASME}, isbn = {978-0-7918-4575-2}, doi = {10.1115/GT2014-25827}, abstract = {Aero engine disc forgings are subjected to heat treatment operations, i.e., solution treatment followed by quenching and artificial aging, with the aim of achieving improved mechanical material properties. During heat treatment high inhomogeneous temperature gradients and long loading times at elevated temperatures occur and lead to the development and partial relaxation of bulk residual stresses. The intention of this paper is to describe the residual stress modelling of a nickel-based ATI 718Plus® superalloy disc forging. For this purpose, an uncoupled thermomechanical finite element problem is solved consisting of a thermal model based on transient, spatially varying heat transfer coefficients (HTCs) and a stress model incorporating the nonlinear material behaviour to account for thermal induced inelastic deformations. A graphical user interface based application has been created for the automatic estimation of the a priori unknown HTCs by using a serial solution procedure for the two dimensional inverse heat conduction problem (IHCP) based on the function specification method. The estimated temperature fields have been compared at the thermocouple positions with the corresponding measurement data and confirm the suitability of the inverse algorithm to this problem. A rate-independent elasto-plastic constitutive model is used to simulate the residual stress formation while quenching the disc forging. Two creep models have been adjusted to uniaxial tensile test data and applied to simulate the stress relaxation during aging. Finally, this paper presents the numerical results of the stress analysis. Copyright © 2014 by Rolls-Royce Deutschland Ltd \& Co KG}, language = {en} } @inproceedings{SpringmannKuehhornRaueretal., author = {Springmann, Marcel and K{\"u}hhorn, Arnold and Rauer, Georg and Giersch, Thomas}, title = {Constitutive Modelling of Plastic and Creep Behavior of the Nickel Base Superalloy ALLVAC® 718PLUS® under Heat Treatment Conditions}, language = {en} }