PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 14 (2019) 467–474 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. © 2019 The Authors. Published by Elsevier B.V. This is n ope access article under the CC BY-NC-ND licens (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of th SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Failure Analysis of Cooling Duct of Top Engine Cowl Panel of Fighter Aircr ft Premkumar Manda*, Satyapal Singh, A K Singh Defence Metallurgical Research Laboratory, Kanchanbagh P.O., Hyderabad – 500 058, India. Abstract Present work describes the failure analysis of cooling duct of a fighter aircraft. The analyzed chemical composition of cooling duct indicates that it is manufactured from Al-based alloy (AA 3003 or its equivalent). Microstructure of cooling duct displays the presence of two phases namely, matrix and insoluble particles. The hardness values at different locations within damaged area of cooling duct reflect nearly same and consistent. The fracture surface of the cooling duct exhibits transgranular features and cracks with little branching. The analyzed hydrogen content in cooling duct is significantly higher (  12 ppm) than the specified one (  1 ppm). However, the alloy used to fabricate cooling duct is not susceptible to typical hydrogen embrittlement. This shows hydrogen pick up during operation. The presence of cracks with branching does reflect features of hydrogen embrittlement. In addition, striations indicative of fatigue features are also observed. It thus appears that the cooling duct has failed due to pick up of large amount of hydrogen as well as vibrational fatigue. © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. Keywords: Cooling duct; Aluminium alloy; Hydrogen embrittlement. 1. Introduction The damaged cooling duct of fighter aircraft was received to find out the root cause of the failure. The main purpose of cooling duct is to cool the two generators and alternator by ram air. It is known that when air is taken aboard in an aircraft during flight, its pressure increases. The temperature of the ram air is significantly low in and around vicinity of the generator and alternator. The ram air may be cool, dry or humid depending upon operating climate of the aircraft. 2nd International Conference on Structural Integrity and Exhibition 2018 Failure Analysis of Cooling Duct of Top Engine Cowl Panel of Fighter Aircraft Premkumar Manda*, Satyapal Singh, A K Singh Defence Metallurgical Research Laboratory, Kanchanbagh P.O., Hyderabad – 500 058, India. Abstract Present work describes the fail re analysis of cooling duct of a fighter aircraft. The analyzed chemical composition of cooling duct indicates that it is manufactured from Al-based alloy (AA 3003 or its equivalent). Microstructure f co ling duct isplays the presence of two phases amely, atrix and insoluble particles. The hardness values at different locations within damaged area of cooling duct refle t early same and consistent. The fracture surface of the cooling duct ex ibits transgranular features and cracks with little branching. The analyzed hydrogen content in cooling duct is signifi antly higher (  12 ppm) tha the specifi d one (  1 ppm). However, the alloy used t fabricat cooling du t is not sus eptible to typi al hydrogen embrittlement. This shows hydrogen pick up during op ration. Th presence of cracks with branc ing do s reflect features of hydrogen embrittlement. In addition, striations indicative of fatigue features re also observed. It thus appears that the cooling duct has failed due to pick up of large amount of hydrogen as well as vibrational fatigue. © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. Keywords: Cooling duct; Aluminium alloy; Hydrogen embrittlement. 1. Introduction The damaged cooling duct f fighter aircraft wa received to find out the root cause of t e failure. The mai purpose of cooling duct is to cool the two generators and alternator by ram air. It is known that when air is taken boar in a aircraft duri g flight, its pr ssure incr ases. The temp rature of the ram air is significantly low in a d around vicinity of the generator and alternator. The ram air may be cool, dry or humid depending upon operating climate of the aircraft. © 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.

*Corresponding author. Tel.: +91-9949663492; fax: +91-40-24340681. E-mail address: prem_manda@yahoo.co.in, premkumarmanda@gmail.com *Corresponding author. Tel.: +91-9949663492; fax: +91-40-24340681. E-mail address: prem_manda@yahoo.co.in, premkumarmanda@gmail.com

2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is a open access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.056