PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3385–3392 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000

www.elsevier.com/locate/procedia www.elsevier.com / locate / procedia www.elsevier.com / locate / procedia www.elsevier.com / locate / procedia

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.422 ∗ Corresponding authors. E-mail address: sicong.ren@mines-paristech.fr; gilles.rousselier@mines-paristech.fr; thilo.morgeneyer@mines-paristech.fr; 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee f ECF21. Fracture in thin sheet tearing test is observed to propagate initially on a flat surface and subsequently turned into a plane with an angle at about 45 ◦ to the initial flat plane. This pheno enon has been widely observed in the literature (Pardoen et al. (2004)). The simulation of those phenomena remains a challenge due to lack of understanding of the mechanism and numerical di ffi culties. The early stage localisation might be an important influencing factor. Hickey and Ravi-Chandar (2016) studied damage in SENT specimens of 6061 aluminium alloy at two di ff erent states (T6 ∗ Corresponding authors. E-mail address: sicong.ren@mines-paristech.fr; gilles.rousselier@mines-paristech.fr; thilo.morgeneyer@mines-paristech.fr; 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Pe r-review under responsibility of the Scientific Committee of ECF21. Fracture in thin sheet tearing test is observed to propagate initially on a flat surface and subsequently turned into a plane with an angle at about 45 ◦ to the initial flat plane. This phenomenon has been widely observed in the literature (Pardoen et al. (2004)). The simulation of those phenomena remains a challenge due to lack of understanding of the mechanism and numerical di ffi culties. The early stage localisation might be an important influencing factor. Hickey and Ravi-Chandar (2016) studied damage in SENT specimens of 6061 aluminium alloy at two di ff erent states (T6 ∗ Corresponding authors. E-mail address: sicong.ren@mines-paristech.fr; gilles.rousselier@mines-paristech.fr; thilo.morgeneyer@mines-paristech.fr; 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Numerical investigation of dynamic strain ageing and slant ductile fracture in a notch d specimen and comparison with synchrotron tomography 3D-DVC S.-C. Ren a, ∗ , G. Rousselier a, ∗ , T.F. Morgeneyer a, ∗ , M. Mazie`re a , S. Forest a a MINES ParisTech, PSL Research University, MAT-Centre des matriaux, CNRS UMR 7633, BP 87 91003 Evry, France Abstract In ductile tearing experiments, a flat crack is often observed to develop normal to the loading direction that subsequently turns into a slant crack. The underlying physical mechanisms are poorly understood. The numerical strategy for reproducing such kind of slant fracture rem ins a chall nge. Recently, the strain field of a 2198 alumi ium alloy CT-like specimen has been measured by lamino(tomo-)graphy combined with digital volume correlation (DVC) (Morgeneyer et al. (2014)). Multiple localisation bands were observed at notch area at early loading stages. The final fracture occurred within an inclined band. Experiments showed evidences of Portevin-Le Chatelier (PLC) e ff ect in this alloy at room temperature. Previous simulations with von Mises, anisotropic plasticity or Gurson-Tvergaard-Needleman (GTN) models were not able to simulate these observations. As the PLC e ff ect produces instabilities and multiple inclined localisation bands, it is considered to be a candidate for the underlying mechanism related to slant fracture. A fully coupled model (Rousselier and Quilici (2015)) combining polycrystalline, PLC, porous plasticity and Coulomb fracture implemented in FE code is used for simulating these phenomena. The PLC model gives intermittent and moving oscillations of the macroscopic plastic strain rate bands. The multiple strain localisation bands obtained by FE simulation for a thin sheet CT-like specimen are similar to the ones observed in laminography with 3D DVC. Crack propagation occurs during strain rate surges. A flat to slant fracture surface observed in laminography is reproduced successfully by the current FE simulation. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Dynamic strain ageing; Finite elements; Aluminum alloy; Slant fracture; Synchrotron laminography; Damage 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Numerical investigation of dynamic strain ageing and slant ductile fracture in a notched specimen and comparison with synchrotron tomography 3D-DVC S.-C. Ren a, ∗ , G. Rousselier a, ∗ , T.F. Morgeneyer a, ∗ , M. Mazie`re a , S. Forest a a MINES ParisTech, PSL Research University, MAT-Centre des matriaux, CNRS UMR 7633, BP 87 91003 Evry, France Abstract In ductile tearing experiments, a flat crack is oft n observ d to develop nor al to the oa ing direction that subsequently turns int a sla t crack. The underlying physical mechanisms are poorly understood. Th numeric strategy for reproducing uch kind of slant fractur remains a challenge. Recently, the strain fi ld of a 2198 aluminium alloy CT-l ke specimen has b en measured by lamino(tomo-)graphy combined with digital volume correl tion (DVC) (Morg neyer et al. (2014)). Multiple localisation bands were observed at otch are at early loading stages. The final fracture occurred within an inclined band. Experim n s show d evidences of Portevin-Le Chateli r (PLC) e ff ect in thi alloy at room t mperature. Previous simulatio s with von Mises, anisotropic plasticity or Gurson-Tvergaard-Needleman (GTN) models were not able to simulate these observ tions. As the PLC e ff ect produces instabilities and multiple i clined localisation bands, t is consid r d to be a c ndidate for the underlying mechanism related to slan fracture. A fully oupled model (Rousselier and Quilici (2015)) c mb ning polycrystall , PLC, poro s plasticity and Coulomb fractur i plemented n FE code is used for simulating these phenomena. The PL model gives ntermittent and moving oscillations of the macroscopic pla tic strain rate bands. The multiple st ain localisation bands obtained by FE simulation for a thin sheet CT-like specimen are similar to the ones observed in laminography with 3D DVC. Crack propagation occurs during strain rat surges. A flat to lant fracture surface observed in laminography is reproduced successfully by the current FE simulation. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Dynamic strain ageing; Finite elements; Aluminum alloy; Slant fracture; Synchrotron laminography; Damage 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Numerical investigation of dyna ic strain ageing and slant ductile fracture in a notched speci en and co parison ith synchrotron tomography 3D-DVC S.-C. Ren a, ∗ , G. Rousselier a, ∗ , T.F. Morgeneyer a, ∗ , M. Mazie`re a , S. Forest a a MINES ParisTech, PSL Research University, MAT-Centre des matriaux, CNRS UMR 7633, BP 87 91003 Evry, France Abstract In ductile tearing experiments, a flat crack is often observed to develop normal to the loading direction that subsequently turns into a slant crack. The underlying physical mechanisms are poorly understood. The numerical strategy for reproducing such kind of slant fracture remains a challenge. Recently, the strain field of a 2198 aluminium alloy CT-like specimen has been measured by lamino(tomo-)graphy combined with digital volume correlation (DVC) (Morgeneyer et al. (2014)). Multiple localisation bands were observed at notch area at early loading stages. The final fracture occurred within an inclined band. Experiments showed evidences of Portevin-Le Chatelier (PLC) e ff ect in this alloy at room temperature. Previous simulations with von Mises, anisotropic plasticity or Gurson-Tvergaard-Needleman (GTN) models were not able to simulate these observations. As the PLC e ff ect produces instabilities and multiple inclined localis tion bands, it is co side d to be a cand dat for the underly mechanism related to slant fractur . A fully coupled model (Rousselier and Quilic (2015)) combining polycrystalline, PLC, porous plasticity an Coulomb fracture implemented in FE code is used for simulating thes phenomena. The PLC model gives intermi tent and moving oscillations of the mac oscopic plastic strain rate bands. The multiple strain localisation bands obtaine by FE simulation for a thin sheet CT-like specimen are similar to the ones observed in laminography w th 3D DVC. Crack propagation occurs during strain rate surges. A flat to slant fr cture surface observed in laminography is reproduced successfully by the current FE simulation. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Sci ntific Committee of ECF21. Keywords: Dynamic strai ag ing; Finite elements; Aluminum lloy; Slant fracture; Synchrotron l minography; Damage Copyright © 2016 The Authors. Published y Elsevier B.V. This is an ope access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). P r-review under esponsibility of the Sci ntific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 1. Introduction 1. Introduction Fracture in thin sheet tearing test is observed to propagate initially on a flat surface and subsequently turned into a plane with an angle at about 45 ◦ to the initial flat plane. This phenomenon has been widely observed in the literature (Pardoen et al. (2004)). The simulation of those phenomena remains a challenge due to lack of understanding of the mechanism and numerical di ffi culties. The early stage localisation might be an important influencing factor. Hickey and Ravi-Chandar (2016) studied damage in SENT specimens of 6061 aluminium alloy at two di ff erent states (T6 1. Introduction