PSI - Issue 12

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 12 (2018) 183–195 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 000–000

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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. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. 10.1016/j.prostr.2018.11.096 ∗ Corresponding author. Tel.: 0691292336 E-mail address: guido.zucca@aeronautica.difesa.it 2210-7843 c 2018 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 / 3.0 / ) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. Estimation of the dura ility of structural compo ents, seen from a procedural perspective, disregards the use and destination aspects, which are parts of machines, building constructions, biomechanical apparatuses, and substantially takes two forms: design and testing. Design, intended as an a priori evaluation of fatigue behavior, is placed in the advanced stages of the development of an object, while maintaining large margins of uncertainty: first of all the exercise. If in static or dynamic sizing it is possible to conservatively resort to the worst case, in durability it would be necessary to know in advance and punctually the history of the component to make a realistic evaluation. The life of the object is then estimated on the basis of hypothesis of use and often it is expressed in one or more corrective ∗ Corresponding author. Tel.: 0691292336. E-mail address: guido.zucca@aeronautica.difesa.it 2210-7843 c 2018 The Authors. Published by Elsevier B.V. This is an op n access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 3.0 / ) Peer-review u der re ponsibility of t Scientific ommitt e of AIAS 2018 International Conference on Stress Analysis. 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. © 2018 The Aut ors. Published by Elsevi r B.V. This is an open access article under the CC BY-NC-ND lice se (http://creativ commons.org/licenses/by-nc-nd/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. AIAS 2018 International Conference on Stress Analysis Fatigue Life Extimation of a Military Aircraft Structure subjected to Random Loads G. Zucca a, ∗ , F. Cianetti b , M. Palmieri b , C. Braccesi b , F. De Paolis a a Italian Air Force, Flight Test Center, Technology Materials for Aeronautics and Space Department, Military Airport M. De Bernandi, via Pratica di Mare, 000040 Pomezia (RM), Italy. b University of Perugia, Department of Engineering, via G. Duranti 93, 06125 Perugia, Italy. Abstract The suspension system of external stores of a military aircraft has reached the fatigue life limit estimated during the design phase, however, some elements suggest that the duration of the structure has been largely underestimated. This work aims to re-evaluate the fatigue life of the system and the potential extension of its use following an experimental numerical approach where, starting from a series of experimental flights in which the structure was instrumented, the forces acting on the system were calculated. Therefore, a methodology was developed to limit the damage calculation time using a hybrid approach that exploits the advantages deriving from the low computational burden typical of the methods in the frequency domain coupled with the Rainflow Counting precision. The study, although penalized by a series of conservative hypotheses, allowed to estimate a residual life equal to past life. It also provided impor ant feedback on the field of applicati of advanced t hniques fo est mating the fatigue lif of aeronaut cal structures subj cted to random loading stories. c 2018 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 / 3.0 / ) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. Keywords: Damage; Fatigue; Frequ ncy domain approac ; Multiaxial stress state; Random lo ds; Finit Elment Analysis. AIAS 2018 International Conference on Stress Analysis Fatigue Life Exti ation of a ilitary Aircraft Structure subjected to Rando Loads G. Zucca a, ∗ , F. Cianetti b , M. Palmieri b , C. Braccesi b , F. De Paolis a a Italian Air Force, Flight Test Center, Technology Materials for Aeronautics and Space Department, Military Airport M. De Bernandi, via Pratica di Mare, 000040 Pomezia (RM), Italy. b University of Perugia, Department of Engineering, via G. Duranti 93, 06125 Perugia, Italy. Abstract The suspension system external stores of a military aircraft has reached the fat gue life l mit estimated during the design phase, however, some elements suggest that the duration of the structure has been largely underestimated. This work aims to re-evaluate the fatigue life of the system and the potential extension of its use following an experimental numerical approach where, starting from a series of experimental flights in which the structure was instrumented, the forces acting on the system were calculated. Therefore, a methodology was developed to limit the damage calculation time using a hybrid approach that exploits the advantages deriving from the low computational burden typical of the methods in the frequency domain coupled with the Rainflow Counting precision. The study, although penalized by a series of conservative hypotheses, allowed to estimate a residual life equal to past life. It also provided important feedback on the field of application of advanced techniques for estimating the fatigue life of aeronautical structures subjected to random loading stories. c 018 The Authors. Published by Elsevier B.V. T i open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 3.0 / ) Pe i under responsibility of the Sc entific Committee of AIAS 2018 International Conference o Stress Analysis. Keywords: Damage; Fatigue; Frequency domain approach; Multiaxial stress state; Random loads; Finite Elment Analysis. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction 1. Introduction Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Estimation of the durability of structural components, seen from a procedural perspective, disregards the use and destination aspects, which are parts of machines, building constructions, biomechanical apparatuses, and substantially takes two forms: design and testing. Design, intended as an a priori evaluation of fatigue behavior, is placed in the advanced stages of the development of an object, while maintaining large margins of uncertainty: first of all the exercise. If in static or dynamic sizing it is possible to conservatively resort to the worst case, in durability it would be necessary to know in advance and punctually the history of the component to make a realistic evaluation. The life of the object is then estimated on the basis of hypothesis of use and often it is expressed in one or more corrective * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt