PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 8 63–68 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 Applicability of local approaches to assessment of cleavage fracture in complex constraint and load history cases J Beswi k a , D Sarzosa b , R Savioli b , P James c , C Ruggieri b , AP Jivkov a * a Mechanics and Physics of Solids Research Group, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, UK b Fracture Mechanics and Structural Integrity Research Group, School of Engineering, University of Sao Paulo, Brazil c Wood, Warrington, Cheshire, UK The paper presents results and analysis from an on-going investigation to better understand and quantify the effects of constraint on cleavage fracture und r various i tial stress and plastic strain c nditions. Specifically, n w fracture t ughness data obtained with three-point bend specimens with crack-to-width ratios 0.4, 0.2 and 0.05 is shown for as-received material and material with 5% initial uniaxial plastic strain. Firstly, analysis with the J-Q approach is used to argue that while pre-strain initial conditions change the fracture toughness, the shape of the failure locus in the J-Q space might remain unaffected. The implication is significant reduction of tests required for assessments taking constraint into account. The potential to use current local approach methods to allow a fracture prediction, which is independent of initial conditions, is then investigated by application of modified Beremin models. It is demonstrated that the local approaches can predict changes in the apparent toughness across the three constraint levels for the as received material. It is further shown that accommodation of load history effects, such as the initial plastic strain, requires an advancement of the classical approach, a subject of on-going work. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: cleavage fracture; very low constraint; initial plastic strain; two-parameter assessment; local approach © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Applicability of local approaches to assessment of cleavage fracture in complex constraint and load history cases J Beswick a , D Sarzosa b , R Savioli b , P James c , C Ruggieri b , AP Jivkov a * a Mechanics and Physics of Solids Research Group, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, UK b Fracture Mechanic and Structural Integrity Research Group, School of Engineering, University of Sao Paulo, Brazil c Wood, Warringt n, Cheshire, UK Abstract The paper presents results and analysis from an on-going investigation to better understand and quantify the effects of constraint on cleavage fracture under various initial stress d plastic strain conditions. Sp cifically, ew fracture toughn ss data obtained with three-point bend specimens with cr ck- o-width ratios 0.4, 0.2 an 0.05 is shown for as-received material and m terial with 5% initial uniaxial pla tic strai . Firstly, nalysis with the J-Q approach is used to argue that whil pre-strain initial conditions change the fracture toughness, the shape of the f ilure locus in the J-Q s ace might r main unaffected. The implicatio is significant reduction of tests required for asses ments taking constraint into account. The potential to use current local ap roach methods to llow a fracture prediction, which i ind pendent of i itial co ditions, is then inves ga ed by application of modified Beremin models. It is demonstrated that the local approaches can predict changes in the apparent toughness across the three constraint levels for the as received material. It is further shown that accommodation of load history effects, uch a t initial plastic strain, requires an advancement of the classical approach, a subject of on-going work. © 2018 The Authors. Published by Elsevier B.V. Peer-review und r respons bility of the ECF22 organizers. Keywords: cleavage fractur ; very low c nstraint; initial plastic strain; two-parameter assessment; local approach © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction Current nuclear reactor pressure vessel (RPV) designs are comprised of several forgings joined through a welding process. The forgings are made from high strength steels, usually a ferritic material co taining brittle second phase articles, such as carbides. At usual plant operating t mperatures (~280°C) th prese ce of these parti les near a Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Current nuclear reactor pressure vessel (RPV) designs are comprised of several forgings joined through a welding process. The forgings are made from high strength steels, usually a ferritic material containing brittle second phase particles, such as carbides. At usual plant operating temperatures (~280°C) the presence of these particles near a Abstract 1. Introduction

* Corresponding author. Tel.: +44-161-306-3765. E-mail address: andrey.jivkov@manchester.ac.uk * Corresponding author. Tel.: +44-161-306-3765. E-mail address: andrey.jivkov@manchester.ac.uk

* 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.2018.12.011