PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 14 (2019) 429–434 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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2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.052 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 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 and Exhibition 2018 Influence of crack closure and local near-tip stress on crack growth life estimation A.N. Savkin a , R. Sunder a, b , D.S. Denisevich a , K.A. Badikov a , A.A. Sedov a * a Volgograd State Technical University, Lenin Avenue 28, Volgograd 400005, Russian Federation b Bangalore Integrated System Solutions (P) Ltd., No. 497 E, 14th Cross, 4th Phase, Peenya Industrial Area, Bangalore 560058, India. Abstract Currently, among other models for crack growth prediction, crack closure models that consider the decrease in stress intensity factor (SIF) range associated with cyclic loading asymmetry are more popular. One of drawbacks of these models is impossibility of considering the loading history sequence. The theory related threshold SIF range and Δ K th and local near-tip stresses, induced by overloads, and postulated that the overload effect in the near-threshold region of growth rates is caused by residual local stresses. The proposed odel applies the local stress and strain approach to estimate stress σ * in the stress concentration region for fatigue analysis. This region is characterized by local near-tip stress σ*, whose amplitude is determined by cyclic inelastic reaction at crack tip. Further development of the model is due to varying nature of the threshold SIF range Δ K th . As a basis, the Forman-Mettu formula was adopted, whi h escribes t e fatigue crack rowth curve in all three egions of fatigue crack growth rat . The range ΔK was determined by the peak load Δ P of the load history. The crack closure was consider d by th Schijve quation, considering the asymmetry of the half-cycle U = f(R) , and eff ctive SIF was estimated by Δ K eff = Δ K*U . Given known SIF range ΔK, the value of the local stress σ * at distanc from the crack tip r* was determined for each half cycle by Neuber and Ramberg-Osgood equations, and threshold SIF was estimated from the analytical formula of К th =f( σ ) . Thus, known loading history made it possible to determine Δ K eff , K max , and K th on each cycle for fatigue life estimation. Mathematical modeling of fatigue crack growth life, especially in near-threshold region of its growth, according to the Sunder’s scheme, showed that investigated aluminum alloy 2024-T3 exhibited crack growth sensitivity to various types of force action, including various types of random loading. 2nd International Conference on Structural Integrity and Exhibition 2018 Influence of crack closure and local near-tip stress on crack growth life estimation A.N. Savkin a , R. Sunder a, b , D.S. Denisevich a , K.A. Badikov a , A.A. Sedov a * a Volgograd State Technical University, Lenin Avenue 28, Volgograd 400005, Russian Federation b Bangalore Integrated System Solutions (P) Ltd., No. 497 E, 14th Cross, 4th Phase, Peenya Industrial Area, Bangalore 560058, India. Abstract Currently, among other models for crack growth prediction, crack closure models that consider the decrease in stress intensity factor (SIF) range associated with cyclic loading asymmetry are more popular. One of drawbacks of these models is impossibility of considering the loading history sequence. The theory related threshold SIF range and Δ K th and local near-tip stresses, induced by overloads, and postulated that the overload effect in the near-threshold region of growth rates is caused by residual local stresses. The proposed model applies the local stress and strain approach to estimate stress σ * in the stress concentration region for fatigue analysis. This region is characterized by local near-tip stress σ*, whose amplitude is determined by yclic inela tic reaction at crack tip. Further development f the model is due to varying nature of the threshold SIF range Δ K th . As a basis, the Forman-Mettu formula was adopted, w ich describes the fatigue crack growth curve in all thr e regions of fatigue crack growth rate. The range ΔK was determined by the peak load Δ P of the load history. The crack closure was considered by the Schijve equation, considering the asymmetry of the half-cycle U = f(R) , and effective SIF was estimated by Δ K eff = Δ K*U . Given known SIF range ΔK, the value of the local stress σ * at distance from the crack tip r* was determined for each half cycle by Neuber and Ramberg-Osgood equations, and threshold SIF was estimated from the analytical formula of К th =f( σ ) . Thus, known loading history made it possible to determine Δ K eff , K max , and K th on each cycle for fatigue life estimation. Mathematical modeling of fatigue crack growth life, especially in near-threshold region of its growth, according to the Sunder’s scheme, showed that investigated aluminum alloy 2024-T3 exhibited crack growth sensitivity to various types of force action, including various types of random loading. © 2018 The Authors. Published by Elsevier B.V. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-r view u der responsibility of the SICE 2018 organizers. © 2018 The Authors. Published by Elsevier B.V. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +7-905-062-68-80. E-mail address: sedov@vstu.ru * Corresponding author. Tel.: +7-905-062-68-80. E-mail address: sedov@vstu.ru