PSI - Issue 5

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 5 (2017) 225–232 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal FE Mesh Generation – Automated Crack Grow Modeling with a View to Stress Intensity Factor Computing Jan Raška a ,* a Aeronautical Research and Test Institute (VZLÚ),Strength of Structures Dept., Beranových 130, Praha – Letňany, 199 05, Czech Republic The damage tolerance design approach, expects the existence of the initial flaw in any structure. To manage the extension of this flaw during service, the fracture mechanics principles are applied. For this purpose, two domains of analysis must be accomplished: First, the crack growth due to variable, periodical load (fatigue load), second, the residual strength of the damaged structure statically loaded. For both analysis, the computing of the fracture mechanics characteristics in each state of the crack opening is indispensable. In practice, the application of the FE method is necessary. By the help of currently used FEM software NASTRAN, the stress intensity factor – K I and K II – can be compute by application of the special element, called CRAC2D. Unfortunately, CRAC2D element is not implemented into the currently used FE pre-processors. Moreover, one application of the CRAC2D element result only in a single value of the K I and K II for the modeled crack length. For these reasons, the fully automated crack growing modeling was developed. Based on the virgin FE model (base FE model without crack), the developed software application generate the appropriate FE model for each desired crack opening. User have only to indicate the crack initiation node and the crack growing path, so-called crack growing scenario (see fig.1). After the data check, the crack is modeled, the CRAC2D element is applied at the crack tip, the FE model is saved, the related job is executed and the resultant K I and K II values are associated with modeled crack length. This step is repeated for each desired crack opening. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committe of ICSI 2017. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal FE Mesh Generation – Automated Crack Grow Modeling with a View to Stress Intensity Factor Computing Jan Raška a ,* a Aeronautical Research and Test Institute (VZLÚ),Strength of Structures Dept., Beranových 130, Praha – Letňany, 199 05, Czech Republic Abstract The damage tol ance design app oach, expe ts the existenc of the initial flaw in any structure. To manage the extension of this flaw during ervice, the f acture mechanics principles are applied. For this purpose, two domains of analysis must e accompli hed: First, the crack gr wth due to variable, er odical load (fa igue load), second, the e dual strength of the damaged structure tatically load d. For both analysis, the computing of the fracture mechanics characteristics in each state of the crack ope ing is ndisp nsab e. I practi e, the application of the FE ethod is necessary. By help of currently used FEM software NASTRAN, the stress intensity factor – K I and K II – can be compute by application of the special el me t, called CRAC2D. Unfortunat y, CRAC2D eleme t i ot implemen ed into the currently used FE p e-processors. Moreover, one application of the CRAC2D element result only in a singl value of the K I nd K II for the modeled crack l ngth. F r these reasons, the fully automated cra k growi g modeling was developed. Based on t e virgin FE model (base FE model without cra k), the developed software application generate the appropriate FE model f r each d sired crack opening. User have only to indic te the crack initiation node and the crack growing path, so-called crack gr wing scenario (se fig.1). After the data check, th crack is mo eled, the CRAC2D element is applied at the crack tip, the FE model is saved, the relat job is executed and the resultant K I and K II values are associated with modeled crack length. This step is repeated for each desired crack opening. © 2017 The Authors. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Crack Growth, Crack Path, FE Model, FEM, Fracture Mechanics, Stress Intensity Factor Keywords: Crack Growth, Crack Path, FE Model, FEM, Fracture Mechanics, Stress Intensity Factor

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. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.121 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. * Correspon ing author. Tel.: +420-225-115-459; fax: +420-225-115-335. E-mail address: raska@vzlu.cz * Corresponding author. Tel.: +420-225-115-459; fax: +420-225-115-335. E-mail address: raska@vzlu.cz