PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 2 (2016) 612–621 Available online at www.sciencedirect.com Sci nceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A thr e-dimensio al model of non-slipping stress corrosion cracking under low loads Longkui Zhu a, b *, Zhengcao Li a , Lijie Qiao b a State Key Laboratory of New Ceramics & Fine Processing, Key Laboratory for Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China b Corrosion and Protection Center, Key Laboratory for environmental fracture of Ministry of Education, School of Materials Science and Engineering, University of Scie ce and Technology Beijing, Beijing 100084, People’s Republic of China Abstract Stress corrosion cracking (SCC) of 316L single-crystal austenitic stainless steel subjected to low loads ( σ nom = 20-40 MPa) in a 45 % boiling MgCl 2 solution was studied using synchrotron X-ray computed tomography, finite element analysis and so on. Results show that there was no surface slip band around the nucleation sites and the tips of short cracks. Three-dimensional reconstruction of discontinuous zig-zag surface SCC crack indicates that the crack was continuous inside the specimen. The obtaining through two-surface trace analysis manifests, rather than {1 1 1} slip planes, the cracks extended long {1 0 0} planes with the lowest surface energy. It is considered that microcle vage and local dissolut on synergistically led to the SCC advance, and microshear was also one of the primarily mi oscopic SCC mechanisms under the high load. The three-dimensional SCC model was created a the low s ress level, where a main SCC crack grew alo g the MPD du to anodic dissolut on, and a microdefect was formed on the crack front. When the micr efect enlarged to a critical size, secondary microcracks nucleated at the stress-concentrated microdefect shoulders. Th , the microcracks propagated to two sid s of the MPD through anodic dissolution, microcleavage or mciroshear, resulting in the formation of the river-like fractography and the discontinuous surface 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A three-dimensional model of non-slipping stress corrosion cracking under low loads Longkui Zhu a, b *, Zhengcao Li a , Lijie Qiao b a State Key Laboratory of New Ceramics & Fine Processing, Key Laboratory for Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China b Corrosion and Protection Center, Key Laboratory for environmental fracture of Ministry of Education, Scho l of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100084, People’s Republic of China Abstract Stress corrosion cracking (SCC) of 316L single-crystal austenitic stainless steel subjected to low loads ( σ nom = 20-40 MPa) in a 45 % boiling MgCl 2 solution was studied using synchrotron X-ray computed tomography, finite element a alysis and so on. Results show that there was n surface slip band around the ucle tion sites and the tips of short cracks. Three-dimen ional reconstruction of discontinuous zig-zag urface SCC crack indicates that the crack was continu us inside the specim . The obtaining through two-surface trace analysis manifests, ther than {1 1 1} slip pl nes, the racks extended along {1 0 0} planes wi h the lowest surface energy. It is considered that microcl avage and local dissolution synergi tically l to the SCC advanc , and icrosh ar was also one of the primarily icroscopi SCC mechanisms under the high load. The three-dim nsional SCC model wa created at the low tress level, where a main SCC crack grew along the MPD due to anodic d ssolut , and a icrodef ct was formed on the crack front. When he icrodefect nl r e to a critical size, seconda y microcracks nucleated at the s r ss-concentrated microdef should r . Then, the microcracks propagated to two ides of the MPD through nodic dissolution, mi rocleavage o mci oshear, resulting i the f rmation of the river-like fractography and t e discontinuous surface SCC cracks w th r without surf ce lipping. © 2016 The Auth s. Published by E sev er B.V. Peer-review under espons bility of the Scientific Committee of ECF21. 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. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. SCC cracks with or without surface slipping. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Single-crystal stainless steel; Stress corrosion cracking; Three-dimensional model; Slip band; Discontinuous cracks Keywords: Single-crystal stainless steel; Stress corrosion cracking; Three-dimensional model; Slip band; Discontinuous cracks

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +86-10-62772513; fax: +86-10-62772513. E-mail address: l.k.zhu@163.com * Corresponding author. Tel.: +86-10-62772513; fax: +86-10-62772513. E-mail address: l.k.zhu@163.com

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.2016.06.079