PSI - Issue 8

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 8 (2018) 41 –421 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Parametric Finite Elements Model of SLM Additive Manufacturing process P.Conti a , 00 * , F. Cianetti a , P. Pilerci a a University of Perugia - Department of Engineering, via G. Duranti 67, Perugia, Italy Abstract An obstacle to the diffusion of additive technology is the difficulty of predicting the residual stresses introduced during the fabrication process. This problem has a co siderable practical interest as evidence by the abundant literature on residual stresses and distortion induced by the SLM (Selective Laser Melting) and EBAM (Electron Beam Additive Manufacturing). The purpose of this paper is to evaluate the effect of different process parameters on the heat distribution and residual stresses in components made with SLM technique. Three aspects are developed and illustrated: a) thermomechanical modeling of the growth process, based on Finite Elements (FE), which considers changes in the behavior of the material (powder  liquid  solid) through the finite element “birth” and “death” technique that enables the progressive activation of the elements as the component grows; b) sensitivity analysis of the model to the physical characteristics of the material (conductivity, specific heat capacity, Young’s modulus). This is an important aspect allowing to focus on the most significant parameters to be determined experimentally with high reliability; c) evaluation of the effects of different process parameters (laser power, scan speed, overlap between adjacent paths) on the process. The article illustrates the theoretical thermal model and the detail of the strategy used in the FE analysis. The most influential characteristics of the material are highlighted and, finally, general criteria for choosing the optimal combination of process parameters to limit the residual stresses are provided. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Parametric Finite Elements Model of SLM Additive Manufacturing process P.Conti a , 00 * , F. Cianetti a , P. Pilerci a a University of Perugia - Department of Engineering, via G. Duranti 67, Perugia, Italy Abstract An obstacle to the diffusion of additive technology is the d fficulty of predicting the residual stresses introduce during the fabricati n process. This problem has a considerable practical i terest as evidenced by the abundant literature o residual stresses and distortion induced by the SLM (Selectiv Laser Melting) and EBAM (El ctron Beam Addit ve Manufacturing). The urpose of this paper is to evaluate the eff ct of different process par meters on the heat distribution and residual stresses in components made with SLM technique. Three aspects are developed a d illustrated: a) thermomechanical modeling of the growth process, bas d o Finite Elements (FE), w ich consid rs changes in th behavior of the materia (powder  liquid  solid) thro gh the fin e element “birth” and “death” technique that e ables the progressive a tivation of the elements as t com onent gr ws; b) sensitivity analysis of the model to the physical characteristics of the material (conductivity, specific heat capacity, Young’s modulus). This is an important spect allowing to ocus o the most significant paramet s to be determined experimentally with igh reliability; c) evaluation of the effects of different process parameters (laser power, scan speed, overlap between adjacent paths) on the process. The article illustrates the theoretical thermal model and the d tail of the strategy used in the FE analysis. The most influential characteri tics of the materi l ar highlighted an , finally, general criteria for choosing the optimal combination of process parameters to limit the residual stresses are provided. © 2017 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: FE model, Additive Manufacturing, Residual stresses, Selective Laser Melting Keywords: FE model, Additive Manufacturing, Residual stresses, Selective Laser Melting

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

* Corresponding author. Tel.: +39 075 585 3710; fax: +39 075 585 3703 E-mail address : paolo.conti@unipg.it * Corresponding author Tel.: +39 075 585 3710; fax: +39 075 585 3703 E-mail address : paolo.conti@unipg.it

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216 Copyright  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis 10.1016/j.prostr.2017.12.041