PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 P o edi Structural Integr ty 5 (2017) 63–68 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Uncertainties f the critical buckling pressure of a tube Hyung-Kyu Kim a * a Korea Atomic Energy Research Institute, 989-111 Daedeokdaero Yuseong-gu Daejeon, 34039 Korea Collapse of a tube is considered in this work. The conservatism of the elastic buckling formula is concerned in particular. It is analyzed using the formula of critical buckling pressure, which consists of the parameters such as the elastic modulus, Poisson ’ s ratio, thickness and radius of a tube. The uncertainty of each parameter is investigated and assessed. In addition, an oval shape of the tube cross section is also co sidered to incorporate the in tial irregular shape possibly bserved. As a result, the thickness uncertainty caused by the dimension tolerance is the most influential to overestimate the critical buckling pressure. Moreover, the ovality of a tube is found more critical than the thickness uncertainty in the prediction of the buckling failure. An example guideline of a tube thickness avoiding the buckling failure is presented accommodating the uncertainties and ovality. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Critical buckling pressure; Uncertainty; Ovality. 1. Introduction When a tu e is ubj ct t an external pressure, it can collapse if the pressure exceeds a critical value. This is termed as a critical buckling pressure. In this case, the external pressure also means the difference of the internal and external pressures if the latter is greater than the former. A tube should not collapse during service to comply with one of the crucial requirements of a tube, the self-standing . One example is a nuclear fuel tube. The pressure in the pressurized water reactor is around 15.5 MPa, and it is exerted to the outer surface of the tube in which a pressure of around 2-10 MPa (varying with the residence time in the reactor) exists. Because the integrity of the fuel tube should be guaranteed during reactor op ration, the tube has to w thstand the external pressure. useong 0 SI 2017. pressure; Uncertainty; Ovality. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 © 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

* Corresponding author. Tel.: +82-42-868-2111; fax: +82-42-863-0565. E-mail address: hkkim1@kaeri.re.kr

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.064 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.