PSI - Issue 2_B

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 2 (2016) 342–349 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 More singular? Self-similar dynamics of dam ge localization and instability in dynamic fracture Oleg B. Naimark a ICMM UB RAS, Academika Koroleva st.,1, Perm 614013, Russia Abstract Dynamic fracture instability is studied for three characteristic statements: dynamic crack propagation, dynamic fragmentation and failure wave initiation to combine theoretical interpretation and “in-situ” high resolution experimental data for dynamically loaded quasi-brittle materials (PMMA, glasses, ceramics and fused quartz). Specific type of criticality (the structural-scaling transitions) was established in solid with defects in terms of two structural variables: defect density tensor (defect induced strain) and structural scaling parameter. Two critical values for structural scaling parameter were found that sepa ate characteristic nonlinearity of free energy release n damage kinetic equation that allowed one to establish specific self-similar solution (bl w-up dissipative structures) responsible for final stage of damage localization and crack initiation. The set of spatial scales of damage localization (that has the image of mirror zones) and corresponding “incubation” time follow from the self-similar solution as the “eigen-values” of non-linear problem. Different scenario of instability of dynamic fracture in mentioned experiments were analyzed as nonlinear dynamic problem in the presence of two self-similar solutions (two attractors): intermediate asymptotical solution for stress field in crack process zone (as the basement for stress intensity factor) and the set of blow-up self-similar solutions for damage localization kinetics pl ying the role of collective mode of dama e localizatio . Theor tic lly predicted flicker noise temporal-spatial statistics was found in dynamic experiments for fused quartz and ceramic rod fragmentation combined with fracto-luminescence recording and analy is of fragment statistics. Resonance excitation of blow-up modes allowed explanation of self similar pattern of multiple spall kin tics (“dynamic branch” under spall) due to “resonance” excitation of blow-up damage localization kinetics. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy More singular? Self-similar dynamics of damage localization and instability in dynamic fracture Oleg B. Naimark a ICMM UB RAS, Academika Koroleva st.,1, Perm 614013, Russia Abstract Dynamic fracture instability is studied for three characteristic statements: dynamic crack propagation, dynamic fragmentation and failure wave in tiation o combine theoretic l interpretation and “in-situ” high resolution experimental d ta for dynamically lo ded quasi-brittl mate ials (PMMA, glasses, ceramics and fused quartz). Specific type of criticalit (the structural-scaling transitions) w s established in olid with defects in terms of two stru tur l variables: defect d n ity ensor (defec i duced str in) and tructural scaling parameter. Two critical val es for structural scaling parameter we e found that separate characteristi nonline rity of free energy release in d mage kin ti equation that llowed on to stablish sp cific elf-similar solution (blow-up issipative structures) responsib e for fin l tage of damage localiz tion and cra k initiation. The set f spatial sc les of damage localization (that has the image of irror zones) and corresponding “incubation” time ollow from the self-si ilar s lut on as the “eigen-values” f non-linear problem. Different sce ario of instability of dynamic fracture in men ed exp riments were analyzed as nonlinear dynam c problem in the presence of two self-similar solutions (two attractors): nt rmediat asymptotical solution for stress field in crack proce s zone (as the ba ement f r stres intensity factor) and the se of blow-up self-similar solutions for dam ge localizati kinetics playing he ole of collective modes of damage localization. Theoretically predicted flicker noise temporal-spa al statistics was found in dynamic xp riments f r fused quartz and eramic rod fragmentation co bined with fr cto-luminescence recording and analysis of ragment statistics. Resonance excitation of blow-up modes allowed explanatio of self similar pattern of multiple spall kine ics (“dynamic branch” under spall) due to “reson nce” excitation f blow-up damage localization kinetic . © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Sci ntific Com ittee of ECF21. Keywords: Damage localization, blow-up self-similar solution, dynamic crack propagation, failure wave, fragmentation statistics 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. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Damage localization, blow-up self-similar solution, dynamic crack propagation, failure wave, fragmentation statistics

Corresponding author. Tel.: +7-342-2378-312. E-mail address: naimark@icmm.ru Corresponding author. Tel.: +7-342-2378-312. E-mail address: naimark@icmm.ru

* 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.

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.2016.06.044