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) 1367–1372 Available online at www.sciencedirect.com Structural Integrity Procedia 0 (20 8) 0– 0 Available online at www.sciencedirect.com Structural Integrity 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 e ff ects on Structural Integrity Influence of inertia and material properties on discrete simulation of dynamic fracture of concrete Josef Kveˇtonˇ a, ∗ , Jan Elia´sˇ a a Faculty of Civil Engineering, Veveri 95, Brno 602 00, Czech Republic Abstract It is well known that the material resistance to fracture increases with increasing strain rate. For relatively slow strain rates, the response is strongly dependent on the material fracture properties such as material strength or fracture energy, whereas with further increase of loading rate, the loading force is getting influenced predominantly by the material inertia. The response of the material changes with strain rate in the sense of loading force as well as character of the crack pattern. The contribution is focused on simulations of fracture experiments at various strain rates. Dynamical concrete fracture is simulated using meso scale discrete model, i.e. a system of interconnected discrete particles. Material properties in the model are randomly distributed within the volume domain. Similar to quasi-static loading rates, the material randomness influences the dynamic fracture as well. Deterministic and probabilistic simulations are compared and the influence of material parameters and their strain rate dependence are discussed. c 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Strain rate e ff ect; Concrete fracture; Dynamics; Inertia influence; Di rete model; Spatial material randomness Increase in loading capacity of concrete with loading rate is usually attributed to inertia: accelerating certain mass to higher velocity demands more energy to be put into the system. In case of quasi-static loading, there is enough time for the micro-cracks to coalesce and localize into one highly damaged zone – macro-crack. With increasing loading rate, the time is not su ffi cient and several cracks are formed, One can also say that the energy accumulated in the material body cannot be dissipated in single crack and many are therefore created. The crack formation in concrete occurs at the scale, where we distinguish individual aggregates. If the resolution of the model realistically captures inner structure of the material, it is able to represent the e ff ect of inertia on fracturing behavior. For the sake of computational cost reduction, only coarse aggregates are typically directly incorporated in the model. Therefore, ECF22 - Loading and Environmental e ff ects on Structural Integrity Influence of inertia and material properties on discrete simulation of dynamic fracture of concrete Josef Kveˇtonˇ a, ∗ , Jan Elia´sˇ a a Faculty of Civil Engineering, Veveri 95, Brno 602 00, Czech Republic Abstract It is well known that the material resistance to fracture increases with increasing strain rate. For relatively slow strain rates, the response is strongly dependent on the material fracture properties such as material strength or fracture energy, whereas with further increase of loading rate, the loading force is getting influenced predominantly by the material inertia. The response of the material changes with strain rate in the sense of loading f rce s well as character of the crack pattern. The contribution is focused on simulations of fracture experiments at vario s strain rates. Dynamical concrete fracture is simulated using meso scale discrete model, i.e. a system of interconnected discrete particles. Material properties in the model are randomly distributed within the volume domain. Similar to quasi-static loading rates, the material randomness influences the dynamic fracture as well. Deterministic and probabilistic simulations are compared and the influence of material parameters and their strain rate dependence are discussed. c 2018 The Authors. Published by Elsevier B.V. P r-review unde responsibility of the ECF22 organizers. Keywords: Strain rate e ff ect; Concrete fracture; Dynamics; Inertia influence; Discrete model; Spatial material randomness 1. Introduction Increase in loading capacity of concrete with loading rate is usually attributed to inertia: accelerating certain mass to higher velocity demands more energy to be put into the system. In case of quasi-static loading, there is enough time for the micro-cracks to coalesce and localize into one highly damaged zone – macro-crack. With increasing loading rate, the time is not su ffi cient and several cracks are formed, One can also say that the energy accumulated in the material body cannot be dissipated in single crack and many are therefore created. The crack formation in concrete occurs at the scale, where we distinguish individual aggregates. If the resolution of the model realistically captures inner structure of the material, it is able to represent the e ff ect of inertia on fracturing behavior. For the sake of computational cost reduction, only coarse aggregates are typically directly incorporated in the model. Therefore, © 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 ∗ Corresponding author. Tel.: + 420-541-147-131 E-mail address: kveton.j@fce.vutbr.cz ∗ Corresponding author. Tel.: + 420-541-147-131 E-mail address: kveton.j@fce.vutbr.cz

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the ECF22 orga izers. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.286