PSI - Issue 6

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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. Copyright © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the MCM 2017 organizers. XXVII International Conference “Mathematical and Computer Simulations in Mechanics of Solids and Structures”. Fundamentals of Static and Dynamic Fracture (MCM 2017) Influence of boundary conditions on stiffness properties of a rectangular nanoplate Anatolii Bochkarev a a Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199804 Russia Abstract This paper presents the state equations of the large deflection of a plate in the framework of the classical nonlinear von K´arma´n theory with surface stresses taken into account. Unlike the original Gurtin–Murdoch model, the present model does not include any non-strain terms in the surface stress–strain relation. It is shown that the classical structure of the potential energy of a deformed nanoplate is preserved with the redefined elastic moduli, which contain the characteristics of a body and a surface, are introduced. This allows applying to nanoplates the known solutions and methods for macroplates. So the difference between the compressive buckling of a macroplate and of a nanoplate is put in evidence, as well as which factors influence this. c ⃝ 2017 The Authors. Published by Els ier B.V. Peer-review under responsibility of the MCM 2017 organizers. Keywords: surface stresses, nanoplate, effective properties, von K´arma´n 1. Von K´arm´an plate model with surface stresses At the beginning of the last century, Gibbs showed that surface tension is present at the boundary between dissimilar materials. A general model of surface stresses as well as surface elasticity has been developed by Gurtin and Murdoch in Gurtin and Murdoch (1975, 1978) and can be reduced to the case of a negligibly thin layer adhering to the underlying material without slipping, and the elastic moduli for both are different. Somewhat later, an atomistic mod l in Mill r and Shenoy (2000), She oy (2005) has supported the idea that this continuum surface model (the GM model) can predict fundamentally the same elastic response. Recently, in problems of nanomechanics, the two-dimensional theories of plates and shells with surface stresses taken into account have been widely used. The surface stresses with the complete GM equation for large deflections of nanoplates have been investigated by the von K´arm´an plate theory in Lim and He (2004) XXVII International Conference “Mathematical and Computer Simulations in Mechanics of Solids and Structures”. Fundamentals of Static and Dynamic Fracture (MCM 2017) Influence of boundary conditions on stiffness properties of a rectangular nanoplate Anatolii Bochkarev a a Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199804 Russia Abstract This paper presents the state equations of the large deflection of a plate in the framework of the classical nonlinear von K´arma´n theory with surface stresses taken into account. Unlike the original Gurtin–Murdoch model, the present model does not include any non-strain terms in the surface stress–strain relation. It is shown that the classical structure of the potential energy of a deformed nanoplate is preserved with the redefined elastic moduli, which contain the characteristics of a body and a surface, are introduced. This allows applying to nanoplates the known solutions and methods for macroplates. So the difference between the compressive buckling of a macroplate and of a nanoplate is put in evidence, as well as which factors influence this. c ⃝ 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the MCM 2017 organizers. Keywo ds: surf ce stresses, nanoplate, effective propertie , von K´arma´n 1. Von K´arm´an plate model with surface stresses At the beginning of the last century, Gibbs showed that surface tension is present at the boundary between dissimilar materials. A general model of surface stresses as well as surface elasticity has been developed by Gurtin and Murdoch in Gurtin and Murdoch (1975, 1978) and can be reduced to the case of a negligibly thin layer adhering to the underlying material without slipping, and the elastic moduli for both are different. Somewhat later, an atomistic model in Miller and Shenoy (2000), Shenoy (2005) has supported the idea that this continuum surface model (the GM model) can predict fundamentally the same elastic response. Recently, in problems of nanomechanics, the two-dimensional theories of plates and shells with surface stresses taken into account have been widely used. The surface stresses with the complete GM equation for large deflections of nanoplates have been investigated by the von K´arm´an plate theory in Lim and He (2004) © 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.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt ∗ Corresponding author. Tel.: +7 812 428 7179. E-mail address: a.bochkarev@spbu.ru ∗ Corresponding author. Tel.: +7 812 428 7179. E-mail address: a.bochkarev@spbu.ru

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2210-7843 c ⃝ 20 7 he Authors. Published by Elsevier B.V. Peer-review under responsibility of the MCM 2017 organizers. 2210-7843 c ⃝ 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the MCM 2017 organizers. 2452-3216 Copyright  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the MCM 2017 organizers. 10.1016/j.prostr.2017.11.027