PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3002–30 9 ScienceDire t Structural Integrity Procedia 00 (2016) 000–000 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com

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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 Effect of M a Stress on Small Fatigue Crack Growth Rate on Low Carbon Steel with Several Simulated HAZ Heat Treatment Hide-aki Nishikawa a *, Yoshiyuki Furuya a a National Institute for Materials Science, 1-2-1 Sengen, Tsukuba-shi, Ibaraki, 305-0047 Japan In this study, to clarify the effect of microstructure of Heat Affected Zone (HAZ) and residual stress of weld on small fatigue crack growth behavior, uniaxial fatigue testing with surface small fatigue crack growth observation were carried out for low carbon steel with three simulated HAZ heat treatment under several mean stress conditions. As a results, ε n a type small crack growth law was also effective to HAZ microstructure under zero mean stress. Under tensile mean stress condition, fatigue fracture life and small fatigue crack growth life were decreased. In addition, it is clarified that small fatigue crack growth rate acceleration under tensile mean stress was able to be evaluated by using Smith-Watson-Topper equivalent strain ε eq which is obtained from mean stress dependency of fatigue fracture life for smooth specimen and ε eq n a type modified small crack growth law was proposed. Furthermore, it is clarified that ε eq was proportional to ε eff which was evaluated by crack opening point measured with Digital Image Correlation technique. It is considered that equivalent strain ε eq implicitly includes small crack growth life and effect of crack closure. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Fatigue; Heat affected zone; Small crack growth rate; Mean stress; Digital image correlation 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effect of Mean Stress on Small Fatigue Crack Growth Rate on Low Carbon Steel with Several Simulated HAZ Heat Treatment Hide-aki Nishikawa a *, Yoshiyuki Furuya a a National Institute for Materials Science, 1-2-1 Sengen, Tsukuba-shi, Ibaraki, 305-0047 Japan Abstract In this study, to clarify the effect of microstructure of Heat Affected Zone (HAZ) and residual stress of weld on small fatigue crack growth behavi r, uniaxial fatigue testing with s face small fatigue crack growth observation were carried out for low carbon steel with re simulated HAZ heat treatment under several mean stress conditi ns. As a results, ε n a type small crack growth law was also eff ctive to HAZ microstructure u der z o m an str ss. Under tensile mean stres condition, fatigue fracture life and sm ll fatigue crack growth life were decreased. In addition, it is clarifie that mall fatigue cra k growth r e acceleration under tensile mean st ess was able to be evaluated by using Smith-Watson-Topper equivalent strain ε eq whic is obtain d fr m mean stress dependency of fatigue fracture lif for smooth specimen and ε eq n a type modified small crack growth law was propos d. Furthermore, it is clarified that ε eq was proportional to ε eff which was ev l at d by crack openi g point easured ith Digital Image Correlati n technique. It is considered that equivalent strain ε eq implicitly includes small crack growth lif and effect of cr ck cl sure. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Fatigue; Heat affected zone; Small crack growth rate; Mean stress; Digital image correlation Copyright © 2016 The Auth rs. Published by Elsevier B.V. This is an open access articl u der 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. Since fatig e fracture of mechanical components are mainly occurred in welding, a lot of fatigue data for welding were a cumulated befo now. However, since these fatigue data were widely scattered, t o much conservative fatigue d sign is frequently required. One of the reason why such problem occurred is th a lots f effe tive fatigue parameter Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Since fatigue fracture of mechanical components are mainly occurred in welding, a lot of fatigue data for welding were accumulated before now. However, since these fatigue data were widely scattered, too much conservative fatigue design is frequently required. One of the reason why such problem occurred is that a lots of effective fatigue parameter Abstract 1. Introduction 1. Introduction

* Corresponding author: E-mail address: NISHIKAWA.Hideaki@nims.go.jp * Corresponding author: E-mail address: NISHIKAWA.Hideaki@nims.go.jp

* 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 ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under 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 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.2016.06.376