PSI - Issue 2_A

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 Struc ural Integrity 2 (2016) 2682–2689 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com

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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 A cohesive-z e model for steel beams strengthen d with pre-stressed laminates Stefano Bennati a , Davide Colonna a , Paolo S. Valvo a, * a University of Pisa, Department of Civil and Industrial Engineering, 56122 Pisa, Italy We analyse the problem of a simply supported steel beam subjected to uniformly distributed load, strengthened with a pre stressed fibre-reinforced polymer (FRP) laminate. According to the assumed application technology, the laminate is first put into tension, then bonded to the beam lower surface, and finally fixed at both its ends by suitable connections. The beam and laminate are modelled according to classical beam theory. The adhesive is modelled as a cohesive interface with a piecewise linear constitutive law defined over three intervals (elastic response, softening response, debonding). The model is described by a set of differential equations with suitable boundary conditions. An analytical solution to the problem is determined, including explicit expressions fo the internal f rces and interfacial stresses. For illustration, an IPE 600 teel beam strengthen d with a Sika® Carbodur® FRP laminate is considered. First, th elastic limit state load of th unstrengthened beam is determined. Then, the loads corresponding to t e elastic limit states in the steel beam, adhesive, and laminate for the strengthened beam are calculated. As a result, the increased elastic limit state load of the strengthened beam is obtained. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Steel beam; FRP strengthening; adhesive; beam theory; cohesive-zone model; analytical solution. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A cohesive-zone model for steel beams strengthened with pre-stressed laminates Stefano Bennati a , Davide Colonna a , Paolo S. Valvo a, * a University of Pisa, Department of Civil and Industrial Engineering, 56122 Pisa, Italy Abstract We analyse the problem of a simply supported steel beam subjected to uniformly distributed load, strengthened with a pre str ssed fibre-reinf rc d p lymer (FRP) laminate. According to the assumed application echnology, the laminate is firs put into tension, then bonded to the beam lower surface, and finally fixed at both its ends by suitable connections. The beam and lamina e are modelled accor ing to cl ssical beam th ory. The adhesive is modelle as a cohesive i t rface with a piecewise l ear constitutiv law defined over three intervals (elastic response, oftening response, debonding). Th model is descr bed by a set of differen al equations with suitabl boundary conditions. An analytical solution to the problem is determine , inclu ing explicit expressions for he internal forces and interfacial stre ses. For illustrati n, a IPE 600 ste l beam st engthened with a Sika® Carbodur® FRP laminate is considered. Fi st, the ela tic limit st t load of the unstrength ned beam is det rmined. The , he lo ds co respondin to the elastic limit state in the steel beam, adh sive, and lami a e for th strengthened b a are calculate . As a result, the increased lastic limit state load of the strengthene bea is obtained. © 2016 The Autho s. Published by El evi r B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Steel beam; FRP strengthening; adhesive; beam theory; cohesive-zone model; analytical solution. Fibre-reinforc d polymers (FRP) are increasingly used in civil engineering for the strengthening of existing constructions. In such applications, th existing structural elements (mad of tradi ional ma erials such as, for instance, masonry, wood, concrete, s e l, etc.) ar str ngthened by adhesively bon ng FRP laminates onto thei Copyright © 2016 The Auth rs. Published by Elsevier B.V. This is an open access article u der 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. Fibre-reinforced polymers (FRP) are increasingly used in civil engineering for the strengthening of existing constructions. In uch applications, the existing structural elements (made of traditional materials such as, for instance, masonry, wood, concrete, steel, etc.) are strengthened by adhesively bonding FRP laminates onto their Abstract 1. Introduction 1. Introduction

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +39-050-2218223; fax: +39-050-2218201. E-mail address: p.valvo@ing.unipi.it * Corresponding author. Tel.: +39-050-2218223; fax: +39-050-2218201. E-mail ad ress: p.valvo@ing.unipi.it

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.2016.06.335