PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 529–534 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 Analysis of fatigue damage of aluminium alloy under multiaxial random vibration Junji Sakamoto a, *, Tadahiro Shibutani a a Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan Many studies have investigated the fatigue damage of materials under vibration. However, the mechanism of vibration-induced fatigue damage remains unclear, and no method has been established for evaluating the vibration fatigue strength. Therefore, it is important to establish an evaluation method for the vibration fatigue strength of materials to ensure appropriate strength in their design. In this study, we performed experiments to investigate the fracture mechanism of a material under multi-axial random vibration. We selected aluminium alloy A5056 as the test material and employed button-head-type specimens with a notch. The multi-axial random vibration experiments were performed at different acceleration inputs (10, 20, 30, 40, 50, 60, and 70 G rms ) within a frequency band of 10 – 5000 Hz. During the vibration tests, we conducted observations of vibration behaviour. After the vibration tests, we observed the fracture surfaces of the specimens using a scanning electron microscope. The results show that the fatigue fracture was due to the bending resonance mode for the given shape and dimensions of the specime s used in this study. In addition, cracks initiated at different areas on the fracture surface and later propagated; subsequently, the cracks coalesced. Finally, we discussed whether the fatigue life of materials subjected to vibration can be predicted using finite element analysis. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Random vibration, Multi-axis, Fatigue damage, Aluminium alloy © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Analysis of fatigue damage of aluminium alloy under multiaxial random vibration Junji Sakamoto a, *, Tadahiro Shibutani a a Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan Abstract Many studies have investigated the fatigue damage of materials under vibration. However, the mechanism of vibration-induced fatigue damage remains unclear, and no m thod has been established for evaluating the vibration fatigue strength. Therefore, it is important to establish an evaluation method for the vibration fatigue strength of ma erials to ensure appropriate strength in their design. In this study, we performed experime ts to investigate the fracture mech nism of a materi l unde multi-axial random vibration. We selected aluminiu alloy A5056 as the test m rial and employ d button-he d-typ specim ns wi h a notch. The multi-axial random vibration experiments were performed at differe t acce eration inputs (10, 20, 30, 40, 50, 60, nd 70 G rms ) with n a frequency band of 10 – 5000 Hz. During the vibration tests, we conducted observations of vibration behaviour. After the vibration t sts, we o served the fracture surfaces of the specimen using a scanning elect on micr scope. The r sults show that fatigue fracture as due to the bending resonance mode for the given shape a d dim nsions of the pecimens used in t is study. In addition, cracks initiated at different areas the fracture surface and later propagated; subsequently, the cracks coalesced. Finally, we discussed whether the fat gue life of materials subjected to vibration can be predicted using finite el ment analysi . © 2018 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the ECF22 organizers. Keywords: Random vibration, Multi-axis, Fatigue damage, Aluminium alloy Many machin s are subjected to random multi-axial vibration, including transportation equipment such as aircraft and automobiles. For their saf and effective oper tion, it is necessary to precisely evaluate the vibration strength of struct ral materials. Many studies have be n conducted on the fatigue failure of m terials subjected to vibration; however, their mechanisms and evaluation meth ds remain unclear. In this study, the fatigue failure behaviour of an aluminium alloy subjected to random multi-axial vibration was analysed by observation of vibration behaviour and fracture surface observation. In addition, we discussed the possibility of predicting the time to failure using finite element analysis. © 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. Many machines are subjected to random multi-axial vibration, including transportation equipment such as aircraft and automobiles. For their safe and effective operation, it is necessary to precisely evaluate the vibration strength of structural materials. Many studies have been conducted on the fatigue failure of materials subjected to vibration; however, their mechanisms and evaluation methods remain unclear. In this study, the fatigue failure behaviour of an aluminium alloy subjected to random multi-axial vibration was analysed by observation of vibration behaviour and fracture surface observation. In addition, we discussed the possibility of predicting the time to failure using finite element analysis. Abstract 1. Introduction 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.2018.12.087