PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com Available o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 9 (2018) 257–264 Available online at www.sciencedirect.com ScienceDirect Structural Int grity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. IGF Workshop “Fracture and Structural Integrity” Numerical simulation of the de-bonding phenomenon of FRCM strengthening systems Ernesto Grande a * Maura Imbimbo b , Sonia Marfia b , Elio Sacco c a Department of Sustainability Engineering, University, Guglielmo Marconi, via Plinio 44, 00193 Roma, Italy. b Department of Civil and Mechanical Engineering, University of Cassino and southern Lazio, via G. di Biasio 43, 03043, Cassino, Italy c Department of Structures in Engineering and Architecture, University of Naples Federico II, Via Claudio 21, 80125, Naples, Italy Abstract Aim of the paper is to present a one dimensional simple model for the study of the bond behavior of Fabric Reinforced Cementitious Matrix (FRCM) strengthening systems externally applied to structural substrates. The equilibrium of an infinitesimal portion of the reinforcement and the mortar layers composing the strengthening systems allows to derive the governing equations. An analytical solution is determined solving the system of differential equations. In particular, a nonlinear shear-stress slip law characterized by a brittle post-peak behavior with a residual shear strength in the post peak phase is introduced for either the lower reinforcement mortar interface (approach 1) or both the lower and the upper interface (approach 2). In the latter approach, a calibration of the shear strength of the upper interface s proposed in order to implicitly account for the ffect of th d mage of the mortar on the bond behavior. Compari ons with experimental data, available in liter ture, are presented in order to assess the reliability of th propose approach. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: FRCM; de-bonding; analytical model; interface 1. Introduction The reinforcement of existing structures has always been a relevant problem both in the technical and scientific civil engineering comm n ty. Lat ly, the study and design of new reinforcement materials is a challenging issue. In IGF Workshop “Fracture and Structural Integrity” Numerical simulation of the de-bonding phenomenon of FRCM strengthening systems Ernesto Grande a * Maura Imbimbo b , Sonia Marfia b , Elio Sacco c a Department of Sustainability Eng eeri g, University, Guglielmo Marco i, via Pl nio 44, 00193 Roma, Italy. b Department of Civil and Mechanical Engineering, University of Cassino and southern Lazi , via G. di Biasio 43, 3043, Cassino, Italy c Department of Structures in Engineering and Architecture, University of Naples Federico II, Via Claudio 21, 80125, Naples, Italy Abstract Aim of the paper is to present a one dimensional simple model for the study of the bond behavior of Fabric Reinforced Ceme titious Matrix (FRCM) strengthening s stems externally applied to structural substrates. The quilibrium of an infinitesimal portion of the reinforcement and the mortar lay rs co p sing the strengthening systems allows to derive the governing equations. An analytical solution is determin d solving t e system of differential equations. In particul r, a nonlinear shear-stress slip la characterized by a brittle post-peak behavior with a residual shear strength in the post peak hase is introduced for either the lower reinforcement mortar interface (approach 1) or both the lower and the upp r inte face (approach 2). In the latter approach, a calibration of t sh ar strengt of the upper interface is proposed in order t implicitly account for the effect f the damage of th mortar on t bond b havior. Comparisons with experimental data, ava lable in literature, are presented in order to assess the reliabi ity of the proposed a proach. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: FRCM; de-bonding; analytical model; interface 1. Introduction The reinforcement of existing structures has always been a relevant problem both in the technical and scientific civil engineering community. Lately, the study and design of new reinforcement materials is a challenging issue. In © 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. E-mail address: ernesto.grande@unicas.it * Correspon ing author. E-mail address: ernesto.grande@unicas.it

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 Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.037 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.