PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1238–1243 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t gri y Procedia 00 (2018) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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 A numerical simulation model of microscopic cleavage crack propagation based on 3D XFEM Kazuki Shibanuma a* , Yuta Suzuki a , Kazuya Kiriyama a , Takuhiro Hemmi a and Hiroyuki Shirahata a a Department of Systems Innovation, the University of Tojyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japana b Research into Artifacts, Center for Engi eeri g, 5-1-5, Kashiwano-ha, Chiba, Japan Abstract We proposed a model of cleavage cr ck propagatio in s eel based on the extended finite lement meth d (XFEM). In the proposed model, the geometry of the polycrystal is modeled independently from the finite element mesh, as well as the crack shape. As the fracture criterion of the cleavage crack propagation, the cleavage plane was formed on the {1 0 0} plane of the grain where the maximum normal stress was applied. As validation of the proposed model, the numerical simulation results of fracture surface morphology were compared with the SEM observation results obtained from the specimen of crack arrest test. The result shows that the proposed model can successfully simulate complicated microscopic cleavage crack propagation behaviors, such as micro branching and wraparound of cracks. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: XFEM; cleavage crack propagation; 1. Introduction Prevention of brittle crack propagation as well as crack initiation is essential as a “double integrity” for large steel structures. Although it is the most critical to prevent fracture initiation by controlling potential defects, it is actually difficult to remove such defects completely. It is thus significant for a realistic integrity approach how to arrest the brittle crack without serious damages of structures (IACS (2015)). The application of materials with high arrestability to the structures is directly effective to ensure the integrity. Therefore, there have been a lot of efforts on researches and developments of the structural steels with higher arrestability. It has been recognized that there is a strong correlation between microstructures and arrest toughness as an empirical knowledge supported by experiments. It was reported that the well-controlled effective grain size and texture have a potential to enhance the arrestability of steel (Shirahata et al. (2018), Handa et al. (2012)). It was also © 2018 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the ECF22 or anizers. ECF22 - Loading and Environmental effects on Structural Integrity A numerical simulation model of microscopic cleavage crack propagation based on 3D XFEM Kazuki Shibanuma a* , Yuta Suzuki a , Kazuya Kiriyama a , Takuhiro Hemmi a and Hiroyuki Shirahata a a Department of Systems Innovation, the University of Tojyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japana b Research into Artifacts, Cent r for Engineering, 5-1 5, Kashiwano-ha, Chiba, Japan Abstract We proposed a model of cleavage crack propagation in steel based on the extended finite element method (XFEM). In the proposed model, the geometry of the polycrystal is modeled indep ndently from the fi it element mesh, as well as the crack shape. As the fracture criterion of the cleavage crack propagation, the cleavage plane was formed o the {1 0 0} plane of the grain where t maximum normal stress was pplied. As valid ti of the proposed model, the numerical simulation results of fracture surface orphology were compared with the SEM observation results obtained from the specimen of crack arrest test. The result shows that the proposed model can successfully simulate complicated microscopic cleavage crack propagation behaviors, such as micro branching and wraparound of cracks. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: XFEM; cleavage crack propagation; 1. Introduction Prevention of brittle crack propagation as well as crack initiation is essential as a “double integrity” for large steel structures. Although it is the most critical to prevent fracture initiation by controlling potential defects, it is actually difficult to remove such defects completely. It is thus significant for a realistic integrity approach how to arrest the brittle crack without serious damages of structures (IACS (2015)). The application of materials with high arrestability to the structures is directly effective to ensure the integrity. Therefore, there have been a lot of efforts on researches and developments of the structural steels with higher arrestability. It has been recognized that there is a strong correlation between microstructures and arrest toughness as an empirical knowledge supported by experiments. It was reported that the well-controlled effective grain size and texture have a p tential to enhance the arrestability of steel (Shirahata et al. (2018), Handa et al. (2012)). It was also © 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.: +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 organizers.

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.2018.12.254