PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1047–1 52 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 Influence of shear-affected-zone due to punching on tensile characteristics of steel plate Kejin Zhang a *, Shigeru Hamada a , Motomichi Koyama a , Tatsuo Yokoi b , Hirosh Noguch a a Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan b Nippon Steel & Sumitomo Metal Corporation, 1 Oaza-Nishinosu, Oita, 870-0992, Japan In punched steel plate, “punched specimen” f om here onwards, the regi n ear the edg of the punched hole is called the shear affected-zone (SAZ), where tensile characteristics are compromised due to the punching process. However, the specific characteristics and influence on the tensile characteristics of the SAZ are unknown. Therefore, it is difficult to predict the effects of punching on the specimen. Here, we evaluated two kinds of specimens: punched and “honed.” The hole of the honed specimen is formed by drilling and polishing, thus there is no SAZ on the honed specimens. In these specimens, we focused on the initiation and propagation of cracks under tensile loading and set the following objectives: (1) Determine whether any special events occur in the fracture mechanism of the punched vs honed specimens under tensile loading. (2) Find the reasons for any special events that occur. In our investigation, a punched specimen showed brittle fracture even within the static range of the strain rate. By failure surface observation of the punched specimens, we found that under tensile loading, cracks caused by the shear stress aligned with the tensile direction initiate in the SAZ. These cracks are the origin of the final fracture of the punched specimen. We assumed that whether the break is a ductile failure or brittle fracture depends on whether the crack tip becomes blunt. The differences in the fracture behaviors are investigated via detailed fracture surface observation. © 2018 The Au hors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 orga izers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental Effects on Structural Integrity Influence of shear-affected-zone due to punching on tensile char teristics of steel plate Kejin Zhang a *, Shigeru Hamada a , Motomichi Koyama a , Tatsuo Yokoi b , Hiroshi Noguchi a a Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan b Nippon Steel & Sumitomo Metal C rporation, 1 Oaza-Nishinosu, Oita, 870-0992, Japan Abstract In punched steel plate, “punched specimen” from here onwards, the region near the edge of the punched hole is called the shear affected-zone (SAZ), where tensile characteristics are compromised due to the punching process. However, the specific characteristics nd influenc on the tensile characteristics of the SAZ are unknown. Therefore, it is difficult to predict the effects of punching on the specimen. H re, we evaluated two kinds of specimens: punched a d “ oned.” The hole of the honed specimen is formed by drilling and polishing, thus there is no SAZ on the honed specimens. In these specimens, we focused on t e initiation and propagation of cracks u er tensile loading and set the following objectives: (1) Determine whether any special events occur in the fracture mechanism of the punched vs ho ed specimens under tensile loading. (2) Find the reasons for any special events that occur. In o r inv stigation, a punched specimen showed brittle fracture even withi the static range of the strain rate. By failure surface observation of the punched specimens, we found that under tensile loading, cracks caused by the shear stress aligned with the tensile direction initiate in the SAZ. These cracks are the origin of th final fracture of the punched specim n. W assumed that whether the break is a ductile failure or brittl fr cture depends on whet r t cr ck tip becomes blunt. The differenc s in the fracture b haviors are investig t d via detaile fracture surface observatio . © 2018 The Authors. Published by Elsevi B.V. Peer-review under responsibil ty of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Punched steel plate; Shear-affected-zone; Shear band; Tensile characteristic; Brittle-ductile transition Keywords: Punched steel plate; Shear-affected-zone; Shear band; Tensile characteristic; Brittle-ductile transition

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. * 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. * Corresponding author. Tel.: +81-92-802-7677; fax: +81-92-802-0001. E-mail address: zkj2b2b@gmail.com 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. * Corresponding author. Tel.: +81-92-802-7677; fax: +81-92-802-0001. E-mail ad ress: zkj2b2b@gmail.com

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.196