PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1171–1176 Available online at www.sciencedirect.com Structural I tegrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia .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 u der r sponsibility of th ECF22 rganizers. ECF22 - Loading and Environmental effects on Structural Integrity An implicit criterion of fracture growth direction for 3D simulation of hydraulic fracture propagation Lapin V.N. a,b, ∗ , Cherny S.G. a,b a Institute of Computational Technologies SB RAS, Lavrentiev av., 6, Novosibirsk, 630090, Russia b Novosibirsk State University, Pirogova st., 2, Novosibirsk, 630090, Russia Abstract Validation of the previously proposed implicit criterion of fracture propagation was carried out. The implicit criterion at each step of the propagation considers the rock stress state both before and after the propagation. It is based on the assumption that the fracture tends to propagate in the ir ction where II and III modes of stress intensity factor (SIF) are zero. Since in most cases both conditions cannot be satisfied simultaneously, the values of the SIF modes II and III are combined in one function and are integrated along the whole front. A few possible propagation directions are considered at each step of the propagation and the one is chosen to provide the minimum of the integral. The criterion parameters was chosen using the comparison with experiment results and semi analytical formulas obtained from three point bend test with twisted fracture. c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: hydraulic fracturing, fracture growth direction, mixed mode 1. Introduction Trajectory of hydraulic fracture is formed at first seconds of the fracture propagation, but it affects the entire fracturing process (near-wellbore pressure loss, pinching, proppant plug, etc.). To simulate the fracture propagation and to predict the trajectory 3D step-by-step model of hydraulic fracture propagation has been proposed in Shokin at al. (2015). The model simultaneously accounts rock deformation in the vicinity of a fracture and a wellbore, fluid flow inside the fracture and the fracture propagation. The 3D elastic equilibrium equations that are solved by the boundary element method. Fluid flow is described by the 2D Reynolds equation that is solved by finite element method. And plane maximum tensile stress (2DMTS) criterion of the fracture propagation is used in this model to predict the fracture propagation direction. Since the fracture propagates under mixed mode loading, it is necessary to apply three-dimensional mixed mode I, II and III criteria while simulating the propagation process. At each point of the fracture front it is ECF22 - Loading and Environmental effects on Structural Integrity An i plicit criterion of fracture growth direction for 3D si ulation of hydraulic fracture propagation Lapin V.N. a,b, ∗ , Cherny S.G. a,b a Institute of Computational Technologies SB RAS, Lavrentiev av., 6, Novosibirsk, 630090, Russia b Novosibirsk State University, Pirogova st., 2, Novosibirsk, 630090, Russia Abstract Validation of the previously proposed implicit criterion of fracture propagation was carried out. The implicit criterion at each step of the propagation con iders the rock stress state both before and after the propagation. It is based on the assumption that the fracture tends to propagate in the direction where II and III modes of stress intensity factor (SIF) are zero. Since in most cases both conditions cannot be satisfied simultaneously, the values of the SIF modes II and III are combined in one function and are integrated along the whole front. A few possible propagation directions are considered at each step of the propagation and the one is chosen to provide the minimum of the integral. The criterion parameters was chosen using the comparison with experiment results and semi analytical formulas obtained from three point bend test with twisted fracture. c 2018 The Authors. Published by Elsevier B.V. r-review und r re ponsibility of the ECF22 organizers. Keywords: hydraulic fracturing, fracture growth direction, mixed mode 1. Introduction Trajectory of hydraulic fracture is formed at first seconds of the fracture propagation, but it affects the entire fracturing process (near-wellbore pressure loss, pinching, proppant plug, etc.). To simulate the fracture propagation and to predict the trajectory 3D step-by-step model of hydraulic fracture propagation has been proposed in Shokin at al. (2015). The model simultaneously accounts rock deformation in the vicinity of a fracture and a wellbore, fluid flow inside the fracture and the fracture propagation. The 3D elastic equilibrium equations that are solved by the boundary element method. Fluid flow is described by the 2D Reynolds equation that is solved by finite element method. And plane maximum tensile stress (2DMTS) criterion of the fracture propagation is used in this model to predict the fracture propagation direction. Since the fracture propagates under mixed mode loading, it is necessary to apply three-dimensional mixed mode I, II and III criteria while simulating the propagation process. At each point of the fracture front it is © 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.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. ∗ Correspon ing author. Tel.: +7-383-330-7373 ; fax: +7-383-330-6342. E-mail address: lapin@ict.sbras.ru 2210-7843 c 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ∗ Corresponding author. Tel.: +7-383-330-7373 ; fax: +7-383-330-6342. E-mail address: lapin@ict.sbras.ru 2210-7843 c 2018 The uthors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. * 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. 10.1016/j.prostr.2018.12.243