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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 Brittle failure i adhesive lap joints - a general Finite Fracture Mechanics approach N. Stein ∗ , P. Weißgraeber, W. Becker TU Darmstadt, FG Strukturmechanik, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany Abstract In the present work a generally applicable failure model for the assessment of crack onset in adhesive lap joints which is based on finite fracture mechanics is presented. The approach combines a general sandwich-type model with a coupled stress and energy criterion that requires only two fundamental failure parameters: the strength and the toughness of the adhesive. The failure model allows for the analysis of various joint configurations featuring a single overlap as e.g. single lap joints, L-joints, T-joints or DCB specimens. In a comprehensive study, the e ff ects of material parameters on the failure load and the limitations of the present approach regarding the joint configuration are discussed by means of a dimensionless brittleness number. Additionally, the findings are compared to results of a numerical approach using cohesive zone models and to experimental data reported in literature. A good agreem nt for a wide range of jo nt configurations is achieved. c 2016 The Aut ors. Publish d by Elsevier B.V. Peer-review under responsibil ty of the Scientific Committee of ECF21. Keywords: Adhesive joints, Joint strength prediction, Brittle failure, Finite fracture mechanics With the growing demand for lighter but more resistant structures adhesive bonding has prevailed and approved itself as a joining method in many engineering applications due to several advantages compared to traditional assembly methods (Adams et al. (1997)). Mechanical fasteners such as rivets or bolts, for instance, induce stress concentrations which typically lead to the premature failure of the structure. Conversely, adhesive joints allow for a more even load transfer with less critical stress concentrations at the overlap’s end. However, for a reliable and safe design of adhesive joints, a profound knowledge of the associated failure behaviour and trustworthy methods for the assessment of the structure’s load bearing capacity are required. The occuring stress concentrations in adhesive joints which are singular in the context of linear elasticity, im pose di ffi culties on the e ff ective joint strength prediction. Classical stress based or energy based criteria can only be evaluated non-locally and require an additional non-physical length parameter for a successful application. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Brittle failure in adhesive lap joints - a general Finite Fracture Mechanics appro ch N. Stein ∗ , P. We ßgr ebe , W. Becker TU Darmstadt, FG Strukturmechanik, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany Abstract In the present work a generally applicable failure model for the assessment of crack onset in adhesive lap joints which is based on finite fracture mechanics is presented. The approach combines a general sandwich-type model with a coupled stress and energy criterion that requires only two fundamental failure parameters: the treng h and the tough ess of th adhes ve. T e failure model allows for th analysis of various joint configurations featuri g a single overlap as e.g. single lap joints, L-joints, T-joints or DCB specimens. In a comprehensive study, the e ff ects of mat rial parameters on the failure load and the limitations of the present pproach regarding the joint c nfigura ion are discus ed by means of a dim nsionless brittleness number. Add tionally, the findings ar compared to results of a numerical approach using cohesive zon models and to experime tal data reported in literature. A good greement for a wide range of joint configurations is achieved. c 2016 Th Authors. Published by Elsevier B.V. Peer-revi w u der esponsibility f the Scie tific Comm ttee of ECF21. Keywords: Adhesive joints, Joint strength prediction, Brittle failure, Finite fracture mechanics 1. Introduction With the growing demand for lighter but more resistant structures adhesive bonding has prevailed and approved itself as a joining method in many engineering applications due to several advantages compared to traditional assembly methods (Adams et al. (1997)). Mechanical fasteners such as rivets or bolts, for instance, induce stress concentrations which typically lead to the premature failure of the structure. Conversely, adhesive joints allow for a more even load transfer with less critical stress concentrations at the overlap’s end. However, f r a reliable and safe design of adhesive joints, a profound knowledge of the associated failure behaviour and trustworthy methods for the assessment of the structure’s load bearing capacity are required. The occuring stress concentrations in adhesive joints which are singular in the context of linear elasticity, im pose di ffi culties on the e ff ective joint strength prediction. Classical stress based or energy based criteria can only be evaluated non-locally and require an additional non-physical length parameter for a successful application. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Brittle failure in adhesive lap joints - a general Finite Fracture echanics approach N. Stein ∗ , P. Weißgraeber, W. Becker TU Darmstadt, FG Strukturmechanik, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany Abstract In the present work a generally applicable failure model for the assessment of crack onset in adhesive lap joints which is based on finite fracture mechanics is presented. The approach combin s a general sa dwich-type model with a coupled stress and energy criterion that requires only two fundamental failure parameters: the strength and the toughness of the adhesive. The failure model allows for the analysis of various joint configurations featuring a single overlap as e.g. single lap joints, L-joints, T-joints or DCB specimens. In a comprehensive study, the e ff ects of material parameters on the failure load and the limitations of the present approach regarding the joint configuration are discussed by means of a dimensionless brittleness number. Additionally, the findings are compared to results of a numerical approach using cohesive zone models and to experimental data reported in literature. A good agreement for a wide range of joint configurations is achieved. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Adhesive joints, Joint strength prediction, Brittle failure, Finite fracture mechanics 1. Introduction With the growing demand for lighter but more resistant structures adhesive bonding has prevailed and approved itself as a joining method in many engineering applications due to several advantages compared to traditional assembly methods (Adams et al. (1997)). Mechanical fasteners such as rivets or bolts, for instance, induce stress concentrations which typically lead to the premature failure of the structure. Conversely, adhesive joints allow for a more even load transfer with less critical stress concentrations at the overlap’s end. However, for a reliable and safe design of adhesive joints, a profound knowledge of the associated failure behaviour and trustworthy methods for the assessment of the structure’s load bearing capacity are required. The occuring stress concentrations in adhesive joints which are singular in the context of linear elasticity, im pose di ffi culties on the e ff ective joint strength prediction. Classical stress based or energy based criteria can only be evaluated non-locally and require an additional non-physical length parameter for a successful application. 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/). P er-review under esponsibility of th 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. 1. Introduction

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.2016.06.247 ∗ Corresponding author. Tel.: + 49-6151-16-26148 ; fax: + 49-6151-16-26142. E-mail address: stein@fsm.tu-darmstadt.de 2452-3216 c 2016 The Authors. Publi hed by Elsevier B.V. e r-review under responsibility of the Scientific Committee of ECF21. ∗ Corresponding author. Tel.: + 49-6151-16-26148 ; fax: + 49-6151-16-26142. E-mail address: stein@fsm.tu-darmstadt.de 2452-3 16 c 2016 The Authors. Publishe by Elsevi r B.V. Peer-r view under responsibility of the Scientific Comm ttee f ECF21. ∗ Corresponding author. Tel.: + 49-6151-16-26148 ; fax: + 49-6151-16-26142. E-mail address: stein@fsm.tu-darmstadt.de 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt