PSI - Issue 13

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 13 (2018) 483–488 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural I tegrity 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 Numerical simulation of crack propagation in high-strength low-alloyed welded steel Elisaveta Doncheva , Bojan Medjo b , Marko Rakin b , Simon Sedmak c , Bojana Trajanoska a a Ss. Cyril and Methodius University of Skopje, Faculty of Mechanical Engineering, 1000 Skopje, Macedonia b University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, 11120 Belgrade, Serbia c Innovation Centre of Faculty of Mechanical Engineering, 11000 Belgrade, Serbia The industrial application of high-strength low-alloyed steel (HSLA) in welded structures has increased the demand for understanding fracture behavior and structural integrity assessment of this type of steel and produced welded joints. The aim of this paper is to simulate the experimental evaluation of the fracture mechanics specimens by using the micromechanical model. The investigation is performed on two standard single edge notch bend (SENB) specimens with imposed crack in the central region. Numerical analysis was carried out by using Simulia Abaqus software package on 2D models used to simulate the damage development on the local level. The comparison between numerical and experimental results is presented through measured values of J-integral, load-line displacement and crack grow h resistanc (J- Δ а ) curves. This paper shows that numeric l simulat ons are p omising in respect to their accuracy. The application of his mo l enables to decr ase the amount of exp nsive experiments for determination of the load lev l that causes crack propagation. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: high strength steels; welded joints; strength mismatching; finite element method; crack propagation; fracture mechanics The application of HSLA steel in modern design of welded structures exposed to high pressure (such as pressure vessels, stora e tanks, penstock, pip s) requires the evidence of operational safety under real loading conditions. Industrial assessment of welded joints is necessary to provide safety, having in mind heterogeneity and the constraint effect on fracture behavior that rise from micro-structural differences in the heat affected zone and the weld metal that usually have low toughness. Structural integrity issues of welding HSLA steels are associated with different problems among which the occurrence of crack-like defects in welded joints is the most common, Jindal et al. (2012). These © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Numerical simulation of crack propagation in high-strength low-alloyed welded st el Elisaveta Doncheva a , Bojan Medjo b , Marko Rakin b , Simon Sedmak c , Bojana Trajanoska a a Ss. Cyril and Methodius University of Skopje, Faculty of Mechanical Engineering, 1000 Skopje, Macedonia b University of Belgrade, Faculty of Technology and Metallurgy, K rne ijeva 4, 11 2 Belgrade, Serbia c Innovation Centre of Faculty f Mechanical Engineering, 11000 Belgrade, S rbi Abstract The industrial application of high-strength low-alloyed steel (HSLA) in welded structures has increased the demand for understanding fracture behavior and structural integrit assessment of this type of steel and produced welded joints. The aim f this paper is to sim late t e experimental ev luation of the fracture mechanics specimens by using the micromechanical model. The inv stigation is perform d on two standard si gle edge notch bend (SENB) specimens with imposed crack in the central regio . Numerical analysis was carried out by using Simulia Abaqus software package on 2D models used to simulate the damage development on the local level. The comparison between numeric l and exp rimental result is presented through measured values of J-i tegral, load-lin displa e ent and crack growth resistance (J- Δ а ) cu ves. This pap r shows that numerical simulations are promisi g in respect to th ir accur cy. Th application f this model enables to decrease the amount f expensive experime ts for determi ation of the load level that causes crack propagation. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: high strength steels; welded joints; strength mismatching; finite element method; crack propagation; fracture mechanics 1. Introduction The application of HSLA steel in modern design of welded structures exposed to high pressure (such as pressure vessels, storage tanks, penstock, pipes) requires the evidence of operational safety under real loading conditions. Industrial assessment of welded joints is necessary to provide safety, having in mind heterogeneity and the constraint effect on fracture behavior that rise from micro-structural differences in the heat affected zone and the weld metal that usually have low toughness. Structural integrity issues of welding HSLA steels are associated with different problems among which the occurrence of crack-like defects in welded joints is the most common, Jindal et al. (2012). These © 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. Abstract 1. Introduction

* 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 o ganizers.

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.2018.12.080