PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 753–76 ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000

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www.elsevier.com/locate/procedia 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Numerical modeling and testing of mechanical behavior of AM Titanium alloy bracket for aerospace applications 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Numerical modeling and testing of mechanical behavi r of AM Titanium alloy bracket for aerospace applications 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. Eugenio Brusa, Raffaella Sesana*, Enrico Ossola DIMEAS, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy A key issue in designing a new product made through the Additive Manufacturing (AM) is the prediction of mechanical properties of material. Several experimental results show that AM-based products are often affected by widespread porosity, low density regions within their volume and anisotropy. Those effects are due to the manufacturing process, despite of efforts spent to improve the process parameters. This paper presents the numerical modelling of a geometrically complex structural bracket for aerospace application, which was re-designed through a topological optimization and produced in Ti-6Al-4V by means of the AM. The design activity herein described required to resort to a suitable model of constitutive properties of material by facing the problem of a large number of porosity/low density areas, as detected by a tomographic analysis of the mechanical component. According to some references an equivalent isotropic and homogeneous model of material was applied. Nevertheless the limitations of that approach were investigated through a validation of the numerical model and a testing activity. It was demonstrated that the Finite Element model based upon the assumptions of homogeneous and isotropic material might be effective in predicting the material and component strength, at least in static design, but even in case of design against fatigue, provided that a suitable experimental characterization of material was performed. The procedure of optimization was then assessed and compared to some preliminary tests performed on the real component, thus providing a preliminary good practice to the industrial partner involved in this research activity. © 2017 The Au hors. Published by Elsevier B.V. Peer-review under responsibility of the Scie tific Committe o ICSI 2017. Eugenio Brusa, Raffaella Sesana*, Enrico Ossola DIMEAS, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Abstract A key issue in designing a new roduct made thro gh the Additive Manufacturing (AM) is the prediction of mechanical properties of material. Several experimental results show that AM-based products are often affected by widespread porosity, low density regions withi their volume and anisotr py. Those eff cts are due to the manufacturing process, despite of efforts spent to improv the process parameters. This paper presents the numerical delling of geometrically omplex structural bracket for aer spac application, which was re-designed through a topological optimiz tion and produc in Ti-6Al-4V by means of the AM. The design activity herein described require to resort to a suitable model of constitutive properties of material by facing the problem of a large number of porosity/low density areas, as detected by a tomographic analysis of t e mechanical com onent. According to some referenc s an equivalent isotropic nd homogeneous model of material was applied. Nev rtheless the limitations of that approach were investigated through a v lidation of the numeri al model and a testing activity. It was emonstrated that the Finite Element model based up n the assumptions of homogeneous and isotropic mate ial might be effective in predicting the material and component strength, at least in static design, but even in case of design against fatigue, provided that a suitable experimental characterization of material was performed. The procedure of optimization was then assessed and compared to some preliminary tests performed on the real component, thus providing a preliminary good practice to the industrial partner involved in this research activity. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Com ittee of ICSI 2017. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +39-011-0906907; fax: +39-011-0906999. E-mail address: raffaella.sesana@polito.it

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.166 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. * Corresponding author. Tel.: +39-011-0906907; fax: +39-011-0906999. E-mail address: raffaella.sesana@polito.it