PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 8 28–33 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect 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. ECF22 - Loading and Environmental effects on Structural Integrity Hard body impact on glass panes and the fracture energy equilibrium Stefan Reich, M. Raghu Sagar Vanapalli Anhalt University of Applied Sciences, building envelope research group, Bauhausstraße 5, 06846 Dessau, Germany The Griffith theory describes the behavior of brittle materials. For the description of a crack creation, an energy equilibrium is used. At annealed glasses, this equilibrium is reduced to a simple formula containing the mechanical energy in the glass and the surface energy needed for crack creation. The paper deals with the question, whether ball drop test allows the demonstration of the crack creation principles. Furthermore, the specific surface energy is the coefficient that describes the energy needed to create cracks. Therefore it will be discussed here whether ball drop tests produce similar specific surface energy values like static tests, e.g. double cantilever of three-point-bending tests. The testing results show a constant surface energy coefficient at different drop height. Nevertheless, the measured coefficient showed a significant difference to statically determined surface energy coefficients. This was explained by the only partly use of the potential energy of the ball drop for the crack creation. The damping of the glass pane, that is supported in a gasket play a significant role in energy absorption. At a ball drop test the energy amount is defined and the energy input cannot be stopped during the experiment. Despite its easy build-up and conduction, the ball drop test seems not to be an appropriate investigation for the fracture mechanism of brittle glass. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Glass, Equilibrium; Surface Energy; brittle fracture; ball drop The design of glass structures seems to be quite easy because of the linear-elastic behavior of the material glass and its isotropy. Therefore, the generally used design approaches deal with the linear-elastic material and provide simple formulas for the ultimate limit state design. If the material starts to fail, the elastic material does not help us to understand the failure process. Rather we need an appropriate theory to understand the failure process in the brittle material such as glass. It is one of the most brittle material known with almost no plastic deformation at the crack tip. Generally, the Griffith theory is used as basis for the description of the fracture mechanics of brittle materials. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Hard body impact on glass panes and the fracture energy quilibrium Stefan Reich, M. Raghu Sagar Vanapalli Anhalt University of Applied Sciences, building envelope research group, Bauhausstraße 5, 06846 Dessau, Germany Abstract The Griffith theory describes the behavior of brittle materials. For the description of a crack creation, an energy equilibrium is used. At annealed glas es, this equilibrium is reduc d to a simple formula ontaining the mechanical energy in the glass and the surface energy needed for crack creation. The paper deals with the question, whether ball drop test allows the demon tr tion of the crack creation principles. Furth rm re, t e specific surfac energy is the co fficient that describes the energy needed to create cracks. Therefore it will b discuss d here wheth r ball d op tests produce similar specific surface nergy values like static tests, e.g. double cantilever of three-point-bending t sts. The testing results show a constant surface energy coefficient at different drop height. Nevertheless, the measured coefficient showed a significant difference to statically determined surface energy coefficients. T is was explained by the only partly us of the potential energy of the b ll drop for the crack creation. The damping of the glass pane, that is supported in a gasket play a significant role in energy absorption. At a ball drop test the energy amount is defined and th energy input cannot be topped during the experiment. Despite its easy build-up and conductio , the ball drop test se ms ot to be an appropriate investigation for the fracture mecha ism of brittle glass. © 2018 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. Keywords: Glass, Equilibrium; Surface Energy; brittle fracture; ball drop 1. Introduction The design of gla s structures se ms to be quite easy because of the linear-elastic behavior of the material glass and its isotropy. Therefore, the generally used design approaches deal with the linear-elastic material and provide simple formulas for the ultimate limit state design. If the material starts to fail, the elastic material does ot help us to understand the failure process. Rather we need an appropriate theory to understand the failure process in the brittle material such as glass. It is one of the most brittle material known with almost no plastic deformation at t e crack tip. Generally, the Griffith theory is used as basis for the description of the fracture mechanics of brittle materials. © 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. Abstract 1. Introduction

* 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 r sponsibility of the ECF22 o ganizers.

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.2018.12.005