PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1725–173 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

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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 Analytical limit load predictions in heterogeneous welded single edge notched tension specimens Sameera Naib a *, Wim De Wael a , Prim ž Štefane b , N nad Gubeljak b , Stijn Hertelé a a Soete Laboratory, Dept. of EEMMeCS, Ghent University, Belgium b Faculty of Mechanical Engineering, University of Maribor, Slovenia Abstract The integrity assess ent of defected welds is dependent on accurate estimations of their load carrying capacity. As welds consist of variable microstructures, a large degree of heterogeneity is to be expected. The variation of constitutive properties within the weld influences the deformati n patterns around the crack and, as a consequence, the load bearing capacity of the joint. Constitutive heterogeneity is simplified in standardized assessments in order to facilitate the analysis and reduce the complexity of its required input. However, these weld simplifications may lead to inaccurate assessments with unknown errors. This motivates the work of the authors, which aims to include the effects of weld heterogeneity into integrity assessment procedures. The presented paper focuses on the prediction of limit load, which allows to calculate the structure’s proximity to plastic collapse. Simplified theorems have been developed to identify lower and upper bound values of limit load. This work explores the predictive accuracy of various methods to estimate the limit load of heterogeneous welds, including lower and upper bound theorems. A parametric study involves 2D plane strain simulations of single-edge notched tension (SE(T)) specimens. Welds consisting of two regions of different material properties (at the root and at the cap) are introduced. The obtained estimations of limit load are then compared against the simulated limit loads. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organiz rs. Keywords: Weld heterogeneity; SE(T); Limit loads; upper and lower bound; sl p lines 1. Introduction Estimation of load carrying capacity of a structure plays a pivotal role in its integrity assessment. In order to predict the load carrying capacity, limit analysis is performed. Focusing on global collapse in this paper, limit analysis is the © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Analytical limit load predictions in heterogeneous welded single edge notched tension specimens Sameera Naib a *, Wim De Waele a , Primož Štefane b , Nenad Gubeljak b , Stijn Hertelé a a Soete Laboratory, Dept. of EEMMeCS, Ghent University, Belgium b Faculty of Mechanical Engineering, University of Ma ibor, Slovenia Abstract The integrity assessment of defected welds is dependent on accurate estimations of their load carrying capacity. As welds consist of variable microstructures, a larg degree of heterogen ity is to be expected. The variation of c nstitutive properties ithin the weld influences the deformation patterns around the crack and, as a consequence, the load bearing capacity of the joint. Constitutive heterogeneity is simplified in standardized assessments in order to facilitate the analysis and reduce the c mpl xity of its req ired input. However, these w ld simplifications may lead to inaccurate assessments with unknown errors. T is motivates the work of the authors, which aims to include the effects of weld heterogeneity into integrity assessment procedures. he presented paper f cuses on the prediction of limit load, which allows to calculate th structure’s proximity to plastic collapse. Simplified theorems have bee developed t identify lower and upper bound v lues of limit load. This work expl res the predictive accuracy of various methods to estimate the limit load of heterogen ous welds, including lower and upper bound theorems. A parametric study inv lves 2D plane strain simulations of single- dge notched tension (SE(T)) specimens. Welds c nsisting of two regions of different material properties (at the root and at the cap) are introduc . The btai ed estimations of limit load are then compared against the simulat d limit loads. © 2018 The Author . Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Weld heterogen ity; SE(T); Limit loads; upper and lower bound; slip lines 1. Introduction Estimation of load carrying capacity of a structure plays a pivotal role in its integrity assessment. In order to predict the load carrying capacity, limit analysis is performed. Focusing on global collapse in this paper, limit analysis is the © 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. E-mail address: sameera.naib@ugent.be * Corresponding author. E-mail ad ress: sameera.naib@ugent.be

* 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.2018.12.363