PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 14 2–14 7 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000

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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 ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Critical plane and multiaxial criteria for in-phase and antiphase cyclic loading B.A. Stratula a,b , A.D. Nikitin a,* , I.S. Nikitin a a Institute for Computer Aided Design of the Russian Academy of Sciences, Moscow, Russia b Moscow Aviation Institute (National Research University), Moscow, Russia Abstract Analytical solutions are obtained for determining of the critical plane orientation for a multiaxial stress state. This critical plane is the plane of initial development of fatigue damage under cyclic loading. The cases of in-phase and antiphase cyclic loading are considered for the classical fatigue range (low-cycle and high-cycle fatigue). Generalizations of the Findley fatigue criterion are proposed taking into account the orientation of critical plane for modes of very-high-cycle fatigue under in-phase and antiphase cyclic multiaxial loading. These generalizations are based on the similarity of the left and right branches of the bimodal fatigue curve. A procedure for determining the parameters of the generalized criterion is described according to the data of two uniaxial fatigue tests for tension-compression at various coefficients of the asymmetry of the cycle. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fatigue fracture; criterion for a multiaxial stress state; critical plane; low cycle fatigue; very-high-cycle fatigue; durabilityt 1. Determination of the critical plane for a multiaxial stress state in LCF and HCF regimes. There are different models and criteria for fatigue failure and fracture for the multiaxial stress state (see, for example, Bourago et al. (2011)) to assess the fatigue durability of various structural elements in real operating conditions. Mo rn a proaches to the o structi n of multiaxial fatigue fracture criteria often use the notion of the critical plane (Papadopoulos (2001), Carpinteri et al. (2011)). One of the first criteria for determining the critical plane for classical low-cycle regimes (LCF, the number of cycles before fracture 10 3 < N <10 5 ) and the high-cycle regimes (HCF, the number of cycles before the fracture 10 5 < N <10 7 ) fatigue was proposed by Findley (1959). ECF22 - Loading and Environmental effects on Structural Integrity Critical plane and multiaxial criteria for in-phase and antiphase cyclic loading B.A. Stratula a,b , A.D. Nikitin a,* , I.S. Nikitin a a Institute for Computer Aided Design of the Russian Academy of Sciences, Moscow, Russia b M scow Aviation Institute (National Re e rch University), Moscow, Russia Abstract Analytical solutions are obtained for determining of the critical plane orientation for a multiaxial stress state. This critical plane is the plane of initial development of fatigue damage under cyclic loading. The cases of in-phase and antiphase cyclic loading are consider d for the classical fatigue r n e (low-cycle and high- ycle fatigue). Generalizations of the Findley fatigue criterion propos d taking into account the orie tation of critic l plane for modes of very-high-cycle fatigue under in-phase and antiph s cyclic multiaxial loading. These gen ralizations are based on the similarity of the left and right branch s of t e bimod l fatigu urve. A procedure for determining the parameters of th ge eralized criteri n is described according to the data of two uniaxial fatigue tests for tensi n-compression at various coefficients of the asymm try of the cycle. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fatigue fracture; criterion for a multiaxial stress state; critical plane; low cycle fatigue; very-high-cycle fatigue; durabilityt 1. Determination of the critical plane for a multiaxial stress state in LCF and HCF regimes. Th re are different models and cri eria for fatigu ailure and fracture for the multiaxial stress state (see, for example, Bourago et al. (2011)) to assess the fatigue durability of various structural elements in real operating conditions. Modern approaches to the construction of multiaxial fatigue fracture criteria often use the notion of the critical plane (Papadopoulos (2001), Carpinteri et al. (2011)). One of the first criteria for determining the critical plane for classical low-cycle regimes (LCF, the number of cycles before fracture 10 3 < N <10 5 ) and the high-cycle regimes (HCF, the number of cycles before the fracture 10 5 < N <10 7 ) fatigue was proposed by Findley (1959). © 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.

* Alexander Nikitin. Tel.: +79654365980. E-mail address: nikitin_alex@bk.ru * Alexander Nikitin. Tel.: +79654365980. E-mail address: nikitin_alex@bk.ru

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216© 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216© 2018 The Authors. Published by Elsevier B.V. Peer review under responsibility of the ECF22 organizers.

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 ECF22 organizers. 10.1016/j.prostr.2018.12.292