PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 9 (2018) 126–135 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Sci nceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000

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

www.elsevier.com/locate/procedia 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. IGF Workshop “ Fracture and Structural Integrity ” Evaluation of the ductile fracture of Q460 steel under two different failure criteria Riccardo Fincato * , Seiichiro Tsutsumi JWRI, Osaka University, 11-1 Mihogaoka, Ibaraki 5670047, Japan Abstract The evaluation and the prediction of the failure behaviour of materials are fundamental in improving the design and the service life of components/structures. Recent studies in continuum mechanics have pointed out that the ductile damage evolution is influenc d by two parameters: the stress tr axiality and the L de angle. In the present work, a coupled elastoplastic and damage constitutive model was adopted for the evaluation of the failure behaviour of Q460 steel under monotonic loading. Two different failure criteria, the modified Mohr Coulomb (Bai and Wierzbicki, 2010) and modified Lemaitre’s criteria (Lemaitre, 1985a), were compared for the description of the crack formation in tensile tests for round notched bars and flat grooved plates. The two different types of geometry are functional to highlight the role of the Lode angle parameters in the ductile fracture. In the same way, the different radii of the notches and grooves are responsible for lower or higher levels of stress triaxiality, affecting the material ductility. The numerical analyses were compared with the experimental and numerical work carried out by Li et al. (2016) proving the reliability of the numerical model. © 2018 The Authors. Publi hed by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. K ywords: Ductile damage; elastoplasticity; monotonic loading; Lode angle; stress triaxiality; The topic of ductile damage acquired a lot of interest in the scientific community since its development due to the importance of understanding the mechanisms that lead to material failure under different loading conditions and in improving the performances and design of structures and components. Since the pioneering works of Kachanov (1958), Lemaitre (1985a), Gurson (1977), Rousselier (1987), the continuum damage mechanics (i.e. CDM) community developed a great number of constitutive models aiming to identify the factors that affect the damage evolution. Among of all these contributions, it is possible to categorize (Bai and Wierzbicki, 2010) into ‘physically based’ models of ductile fracture, that aim to identify a physical mechanism of nucleation, growth and coalescence of the voids, and the ‘empirical fracture’ models, where the failure criteria are formulated to fit experimental evidences. A part from the different point of observation of the ductile fracture phenomenon all the theories agree that the stress triaxiality and the Lode angle parameter play a fundamental role in the degradation IGF Workshop “ Fracture and Structural Integrity ” Evaluation of the ductile fracture of Q460 steel under two different failure criteria Riccardo Fincato * , Seiichiro Tsutsumi JWRI, Osaka University, 11-1 Mihogaoka, Ibaraki 5670047, Japan Abstract The evaluation and the prediction of the failure behaviour of materials are fundamental in improving the design and the service life of components/structures. Recent studies in continuum mechanics have pointed out that the ductile damage evolution is influenced by two parameters: the stress triaxiality and the Lode angle. In th present work, a coupled elastoplastic and dam ge constitutive model was dopted for the evalua ion of the failure b haviour of Q460 steel under monotoni loading. Two different failure criteria, the modified Mohr Coulomb (B i and Wierzbicki, 2010) a d modified Lemaitre’s criteria (Lemaitre, 1985a), were compared for the description of the cra k formation in tensile tests for round notched bars and flat gr oved plates. The two diffe nt types of geometry are functional to h ghlight the role of th Lode angle par met rs in the ductile fracture. In the same way, the differe t radii of the notches and groov s re responsible for l wer or higher levels of stress triaxiality, affecti g th material ductility. The numerical alyses were comp r d with the experimental and numerical work carried out by Li et al. (2016) proving the reliability of the numerical model. © 2018 The Authors. Publ shed by Elsevier B.V. Peer- eview under responsibility of the G upp Italiano Frattura (IGF) ExCo. Keywords: Ductile damage; elastoplasticity; monotonic loading; Lode angle; stress triaxiality; 1. Int oduct on The topic of ductile damage acquired a lot of interest in the scientific community since its development due to the importance of understanding the mechanisms that lead to material failure under different loading conditions and in improving the performances and design of structures and components. Since the pioneering works of Kachanov (1958), Lemaitre (1985a), Gurs n (1977), Rousselier (1987), the co tinuum damage mecha ics (i.e. CDM) community develope a great number of constitutive models aiming to identify the factors that affect the damage evolution. Among of all these contributions, it is possible to categorize (Bai and Wierzbicki, 2010) into ‘physically based’ models of ductile fracture, that aim to identify a physical mechanism of nucleation, growth and coalescence of the v ids, nd the ‘e pirical fracture’ models, where the failure criteria are formulated to fit experimental evidences. A part from the different point of observati n of the ductile fracture phenomenon all the theories agree that the stress triaxiality nd the Lode angle parameter play a fundamental r le in the degradation IGF Workshop “ Fracture and Structural Integrity ” Evaluation of the ductile fracture of Q460 steel under two different f il criteria Riccardo Fincato * , Seiichiro Tsutsumi JWRI, Osaka University, 11-1 Mihogaoka, Ibaraki 5670047, Japan Abstract The evaluation and the prediction of the failure behaviour of materials are fundamental in improving the design and the service life of components/structures. Recent studies in continuum mechanics have pointed out that the ductile damage evolution is influenced by two paramet rs: the stress triaxiality and the Lode angle. In the present work, a coupled lastoplastic and damage constitutive model was adopted for the evaluation of t e failure behaviour of Q460 steel under monotonic loading. Two different failure criteria, the modifie Mohr Coulomb (Bai and Wierzbicki, 2010) and modified Lemaitre’s criteria (Lemaitre, 1985a), were compared for the escription of the crack formation in tensile tests for round notched bars and flat grooved plates. The two different types of g ometry are functional to hig light t role of the Lode angle parameters in the ductile fracture. In the same way, the different radii of the notches and grooves are responsible for lower or higher levels of stress triaxiality, affecting the material ductility. The numerical an lyses were com ared with the experimental and numerical work carried out by Li et al. (2016) proving the reliability of the numerical model. © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo It liano Fr ttura (IGF) ExCo. K ywords: Ductile damage; elastoplasticity; monot nic lo ding; Lode angle; stress triaxiality; 1. Introduction The topic of ductile damage acquired a lot of interest in the scientific comm ity sinc its development due to the importance of understanding the mechanisms that lead to material failure under different loading conditions and in improving the performanc s and design of structures and compo ents. Since the pioneering works of Kachanov (1958), L maitre (1985a), Gurson (1977), Rousselier (1987), the conti uum damage mech nics (i.e. CDM) community developed great number of constitutive mod ls aiming to identify the factors that affect the damage evolution. Among all these cont ibutions, it is possible to categorize (Bai and Wierzbicki, 2010) into ‘physically bas d’ models of ductile fracture, that aim to identify a physical mechanism of nucleation, growth and coalescence of th voids, and the ‘ mpirical fracture’ models, where the failure criteria are formulated to fit experimental evidences. A part from the different point of observation of the ductile fracture phenomenon all the theories agree that the stress triaxiality and the Lode angle parameter play a fundamental role in the degradation IGF Workshop “ Fracture and Structural Integrity ” Evaluation of the ductile fract r of Q460 steel under two different failure criteria Riccardo Fincato * , Seiichiro Tsutsumi JWRI, Osaka University, 11-1 Mihogaoka, Ibaraki 5670047, Japan Abstract The evaluation and the pred ction of the failure behavio r of materials are fundamental in improving the design a d the servic life of components/structures. Recent studies in continuum mechanics hav pointed out that e ductil damag evolution is influenced by tw paramet rs: the stress triaxiality and the Lod angle. In the present work, a coupled elastoplastic and damag constitut ve model was adopted for the evalu tion f fail e behaviour of Q460 ste under monotonic loading. Two different failure criteria, e modifie Mo r Co lomb (Ba and Wierzbicki, 2010) and modified Lemai r ’s criteria (Lemaitre, 1985a), were compar for h escription of the crack formation in ensile tes s for round otched bars and flat grooved plat s. The two different typ of geometry are func ional to highlight he rol of the Lode ng e param ters in the duc il fracture. In the same wa , the different radii of t e notches and grooves ar responsibl for lower or higher levels of stress triaxiality affecting the material ductility. The numerical an lyses were compared with the experimental and numerical work carried out by Li et al. (2016) pr ving the reliability of th numerical model. © 2018 The Autho s. Published by Elsevier B.V. P er-review under espons bility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Ductile damage; elastoplasticity; monotonic loading; Lode angle; stress triaxiality; 1. Introdu ti n The topic of ductile damage acquired a lot of interest in the scientific c mm nity sinc its dev lopment due to the imp rtance of unders anding the mecha isms that lead to material failure der diff rent loading conditions and in improving th performances and d sign of tructures and components. Since th pioneering works of Kachanov (1958), L maitre (1985a), Gurson (1977), Rouss lier (1987), th conti uum damage mechanics (i.e. CDM) community d velop d great number of constitutive models aiming to ide tify the factors that ffect the damage volution. Among f ll these contributions, it is possible to categorize (Bai and Wierzbicki, 2010) into ‘phys cally bas d’ models ductile fractur , that a m to identify a physical mechanism of nucleation, growth and coalesc nc of the void , and the ‘ mpirical fracture’ models, where the failur criteria are for ulated to fit experim ntal evidenc s. A part from th different point of observation of th ductil fracture pheno enon all the theories agree that the stress triaxiality and the Lode angle parameter play a fundamental role in the degradation © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.021 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Corresponding author. Tel.: +81-6-6879-8667; E-mail address: fincato@jwri.osaka-u.ac.jp 45 -3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under resp nsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Corresponding author. Tel.: +81-6-6879-8667; E-mail address: fincato@jwri.osaka-u.ac.jp 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Corresponding author. Tel.: +81-6-6879-8667; E-mail address: fincato@jwri.osaka-u.ac.jp 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Correspon ing author. Tel.: +81-6-6879-8667; E-mail ad ress: fincato@jwri.osaka-u.ac.jp