PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1077–1084 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Influence of Corrosive NaCl solution on Life times of 7075 Aluminum alloy under Combined Fatigue loading in the VHCF Regime M. Meischel a , S.E. Stanzl-Tschegg a, *, A. Arcari b , N. Iyyer b , N. Phan c a University of Natural Resources and Life Sciences, BOKU Vienna, Peter Jordan St. 82, 1190 Wien, Austria b Technical Dat Analysis, Inc.(TDA), 3190 Fa rview Park Drive, Suite 650, Falls Church, VA 22042 USA c US Naval Air System Command, P tuxent River, MD, USA Abstract The loading histories of aircrafts and rockets are complex and the components are exposed to combined loading conditions with high numbers of high-frequency cycles superimposed to lower-frequency carrier vibrations. The amplitudes of both frequency ranges usually are variable. The small-amplitude cycles arise from several discrete sources such as structural vibrations which are especially critical at s ecial compo nts and pl c of an aircraft. The environment plays another important role and ambi nt air and se -water have to be consid red. Almost no knowledg xists of the material response in the VHCF regime, especially conc rning the environmental influence. In t is study, experiments we e performed on aluminum alloy 7075-T651 in a 3.5%- sodium-chloride solution and in labo atory air of 22 °C of 50% relativ humidity at high (10 5 – 10 8 ) and very high numbers of cycl s (5 × 10 8 – 10 10 ). The oading sequences consisted of a low-frequency square wave (0.4 to 1 Hz), being superimposed with a high frequency 20 kHz random vibration. The random vibrations were simulated by a Gauss distribution allo ing stress ranges of 10 to 70 MPa or alternatively 50 to 90 MPa. Stress/strain vs. life time curves were measured. The results were correlated with in-situ microscopy observations of the specimen surfaces and with post-experimental fracture-surface images. This technology allowed identifying fatigue crack initiation and propagation stages being needed for an interpretation of the relevant fatigue-life 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Influence of Corrosive NaCl solution on Life times of 7075 Aluminum alloy under Combined Fatigue loading in the VHCF Regime M. Meischel a , S.E. Stanzl-Tschegg a, *, A. Arcari b , N. Iyyer b , N. Phan c a University of Natural Resources and Life Sciences, BOKU Vienna, Peter Jordan St. 82, 1190 Wien, Austria b Technical Data Analysis, Inc.(TDA), 3190 Fairview Park Drive, Suite 650, Falls Church, VA 22042, USA c US Naval ir System Comma d, Patuxent River, MD, USA Abstract The loading histories of aircrafts and rockets are complex and the components are exposed to combined loading conditions with high numbers of high- requency cycles superimposed to lower-frequency carrier vibrations. The amplitudes of b th frequency ranges usually are variable. The smal -amplitude cycles arise from sev ral disc ete sou ces such as structural vibrati ns which are especially critical at special components and places of an aircraft. The environm nt plays another important role and ambient air and sea-water have to be considered. Almost no knowledge exists of the material respo se in the VHCF r gime, especially concerning the e vironm ntal influence. In this study, experiments were performed on aluminum alloy 7075-T651 in a 3.5%- s dium-chloride solution a d in laboratory air of 22 °C f 50% relative humidity at high (10 5 – 10 8 ) and very high numbers of cy les (5 × 10 8 – 10 10 ). The loading sequences consisted a low-f equ ncy square wave (0.4 to 1 Hz), being superimposed with a high frequency 2 kHz random vibration. Th random vibratio s were simulated by a Gauss d stribution allowing stres ranges of 10 to 70 MPa or alternatively 50 to 90 MPa. Stress/stra n vs. life tim curv s were me s red. Th esults were correlated with in-situ microscopy observations of he sp cimen surfaces and with post-exp riment l fr cture-surf c images. This technology all wed identifying fatigue crack initiation and propagation stages bei g needed for an interpretation of the relevant fatigue-life mechanisms under env ronmental i fluences. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Copyright © 2016 The Authors. Published by Els vier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. mechanisms under environmental influences. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Superimposed loading; 20 kHz-random fatigue; very high cycle fatigue; corrosive environments; 7075 Al alloy. Keywords: Superimposed loading; 20 kHz-random fatigue; very high cycle fatigue; corrosive environments; 7075 Al alloy.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +43 1 47654 5160; fax: +43 1 47654 5159. E-mail address: Stefanie.tschegg@boku.ac.at * Corresponding author. Tel.: +43 1 47654 5160; fax: +43 1 47654 5159. E-mail address: Stefanie.tschegg@boku.ac.at

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 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/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.138