PSI - Issue 2_B

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 Struc ural Integrity 2 (2016) 3135–3142 Available online at www.sciencedirect.com Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000

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Structural Integrity Procedia 00 (2016) 000–000

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.391 ∗ Corresponding author. Tel.: + 32-9 345 12 82; fax: + 32-9 245 75 12. E-mail address: Reza.HojjtaiTalemi@arcelormittal.com 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. ∗ Corresponding author. Tel.: + 32-9 345 12 82; fax: + 32-9 245 75 12. E-mail address: Reza.HojjtaiTalemi@arcelormittal.com 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. The HSS grades combine outstanding mechanical properties (very high strength, fatigue resistance and toughness) with good formability and weldability. The guaranteed high yield strength of these grades makes it possible to achieve substantial weight reduction through thickness reduction, whilst maintaining overall performance and safety. These The HSS grades combine outstanding mechanical properties (very high strength, fatigue resistance and toughness) with good formability and weldability. The guaranteed high yield strength of these grades makes it possible to achieve substantial weight reduction through thickness reduction, whilst maintaining overall performance and safety. These 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy On e ff ect of pre-bending process on low cycle fatigue behaviour of high strength steel using lock-in thermography Reza H. Talemi a, ∗ , Saosometh Chhith b , Wim De Waele b a ArcelorMittal Global R & D Gent-OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium b Soete Laboratory, Ghent University, Technologiepark Zwijnaarde 903, 9052 Zwijnaarde, Belgium Abstract The application of High Strength Steel (HSS) on di ff erent structural components is becoming more attractive. They have a fine grain structure, low carbon content for improved weldability, and controlled internal purity. These steel grades are frequently used for structural applications. There are a lot of steel components of the considered applications that are subjected to bending and fatigue loading conditions, respectively. It is well known that under critical loading conditions, cyclic stress, which exceeds the material yield stress, can occur at some critical locations such as the inner side of bent components. Combining these two aspects, i.e. the bending process followed by fatigue loading, causes multiple micro-crack initiation inside the inner surface of the bending area, which is followed by propagation of the cracks up to final rupture of material. The main objective of the present study is to investigate the e ff ect of pre-bending process of HSS subjected to low cycle fatigue loading conditions, since so far only very limited amount of research has been focused in this direction. For this purpose, in the first step, a new test set-up was designed to take into account the e ff ect of pre-bending process when the fatigue load has been applied. Lock-in thermography technique was used to monitor the incremental temperature variation during fatigue cycling at the bending root. Using the temperature evolution, the crack initiatio and propagation lifetimes were separated from total lifetime. Fractography and Sc nning Electron Micro copy (SEM) analyses w re performed o study the fracture surface of specimens after bending and fatigue testing. Furth mor , numerical tec nique approac was used to model th bending and spring back pro esses along with th fatigu loading in order to understand he e ff ect of bending process on fatigue b havi ur of test d material. The developed fi it element model provides more information about the multiaxial strain and stress states at and near the bending root 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy On e ff ect of pre-bending process on low cycle fatigue behaviour of high stre gth steel using lock-in thermo raphy Reza H. Talemi a, ∗ , Saosometh Chhith b , Wim De Waele b a ArcelorMittal Global R & D Gent-OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium b Soete Laboratory, Ghent University, T chnologiepark Zwijnaarde 903, 9052 Zwijnaarde, Belgium Abstract The application of High Strength Steel (HSS) on di ff erent structural components is becoming more attractive. They have a fine grain structure, low carbon content for improved weldability, and controlled internal purity. These steel grades are frequently used for structural ap lications. There are a lot of steel components of the considered applications that are subjected to bending and fatigue loading conditions, respectively. It is well known that under critical loading conditions, cyclic stress, which exceeds the material yield stress, can occur at some critical locations such as the inner side of bent components. Combining these two aspects, i.e. the bending process followed by fatigue loading, causes multiple micro-crack initiation inside the inner surface of the bending area, which is followed by propagation of the cracks up to final rupture of material. The main objective of the present study is to investigate the e ff ect of pre-bending process of HSS subjected to low cycle fatigue loading conditions, since so far only very limited amount f research has been focused in this direction. For this purpose, in the first step, a new test set-up was designed to take into account the e ff ect of pre-bending process when the fatigue load has been applied. Lock-in thermography technique was used to monitor the incremental temperature variation during fatigue cycling at the bending root. Using the temperature evolution, the crack initiation and propagation lifetimes were separated from total lifetime. Fractography and Scanning Electron Microscopy (SEM) analyses were performed to study the fracture surface of specimens after bending and fatigue testing. Furthermore, numerical technique approach was used to model the bending and spring back processes along with the fatigue loading in order to understand the e ff ect of bending process on fatigue behaviour of tested material. The developed finite element model provides more information about the multiaxial strain and stress states at and near the bending root after bending process and applied axial fatigue load. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. K ywords: Ben ing proces ; Low cycle fatigu ; Lock-in ther ography; Numerical modelling Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativ commons.org/licenses/by-nc-nd/4.0/). P r view under es on ibility of the Scientific Committe of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. after bending process and applied axial fatigue load. c 2016 The Authors. Published by Elsevi r B.V. Peer-revi w under r sponsibility of the Scientific Committee of ECF21. Keywords: Bending process; Low cycle fatigue; Lock-in thermography; Numerical modelling Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 1. Introduction 1. Introduction