PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1059–1 64 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural I tegrity 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 Statistical peculiarities of the mechanical response of loaded solids at the pre-fracture stage I.Yu. Smolin a,b *, P.V. Makarov a,b , A.S. Kulkov a,b , M.O. Eremin a,b , V.A. Tunda b , V.A. Mikushina a,b a Tomsk State University, Lenin Ave., 36, Tomsk 634050, Russia b Institute of Strength Physics and Materials Science SB RAS, Akademicheskii Av ., 2/4, Tomsk 634055, Russia The statistical analysis of the spatiotemporal dynamic mechanical response up to fracture for the loaded marble and ceramic specimens was performed. The revealed changes in the statistical parameters, which have common features in both experiments under consideration and simulation studies carried out before, can be regarded as precursors of catastrophic fracture. Time series reflecting the mechanical response evolution for the solids loaded up to fracture were analyzed. In the experiments being discussed, the velocity-time histories were measured by a laser-based technique. Statistical analysis was carried out by different methods in the suitable software available. Autocorrelation function indicates that the process has a high degree of autocorrelation. Cross-correlation analysis by the sliding window method showed that a high level of the correlation coefficient of the catastrophic fracture stage with the previous damage accumulation process is observed only in a very short time interval approximately equal to 8-10 times of the failure yield to the critical stage. Spectral analysis based on the fast Fourier transform of the signal (FFT) and the 2D hodograph of the FFT complex vector revealed a fractal nature of the deformation and subsequent fracture. Comparing enlarged and original hodograph fragments vividly demonstrate the multiscale character of fracture. Wavelet analysis using a symmetric Daubechies wavelet well captures short signal emissions corresponding to local failures. Their growth as th fracture point is pproached shows that larg -scale catastrophe is close. ECF22 - Loading and Environmental effects on Structural Integrity Statistical peculiarities of the mechanical response of loaded solids at the pre-fracture stage I.Yu. Smolin a,b *, P.V. Makarov a,b , A.S. Kulkov a,b , M.O. Eremin a,b , V.A. Tunda b , V.A. Mikushina a,b a Tomsk State University, Lenin Ave., 36, Tomsk 634050, Russia b Institute of Strength Physics and Mater als Science SB RAS, Akade icheskii Ave., 2/4, Tomsk 634055, Russia Abstract The statistical an lysis of th spatiotemporal dynamic mechanical response up to fracture for the loaded marble and ceramic specimens was performed. The reveal d changes in the statistical parameters, which have common features in both experiments under consideration and simulation stu ies carried out before, n be regarded as precursors of catastrophic fracture. Time serie refl cting th mech ical response evolution for the solids loaded up to fr ctu were analyzed. In the experiments being discussed, th velocity-time histori s were measu ed by a la er-based technique. Statistical l sis was carri d out by differe t methods in the suitable software available. Autocorrelation function indicates that the process has a high degree of autocorrelation. Cross-correlation analysis y the sliding window method showed that a hig level of the correlation coefficient of the catastrophic fractu e stage with the previous amage accumulati n pr cess is observed only in a very short time interval approximately equal to 8-10 tim s of the failure yiel to the critical st ge. Spectral analy is based on the fast Fourier transform of the signal (FFT) and the 2D hodograp of the FFT compl x ve tor rev aled a fractal nature of the deformation and subsequent fracture. Comparing enlarged and o iginal hodograph fragments vividly demonstr te the m ltiscale character of fracture. Wavelet analysis using a symmetric Daubechi s vel t well captures short signal e issions correspo ding to local failures. Their growth s the fracture p int is proached shows that a large-scale catastrophe is close. © 2018 The Authors. Published by Els v er B.V. Peer-review under responsibility of the ECF22 organizers. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywo ds: Mecha ical Abstract Keywords: Mechanical response; statistical analysis; experiment, laser Doppler vibrometer; nonlinear dynamical system onse; statistical analys s; experiment, las r Doppler vibrometer; nonlinear dynamical system

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* 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 o ganizers. * Corresponding author. Tel.: +7-3822-286-875; fax: +7-3822-492-576. E-mail address: ismolin@ftf.tsu.ru * Corresponding author. Tel.: +7-3822-286-875; fax: +7-3822-492-576. E-mail ad ress: ism lin@ftf.tsu.ru

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.2018.12.223