PSI - Issue 3

ScienceDirect Available online at www.sciencedirect.com Av ilable online at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 3 (2017) 545–552 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

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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. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy A new advanced railgun system for debris impact study A. Vricella*, A. Delfini, A. Pacciani, R. Pastore, D. Micheli, G. Rubini, M. Marchetti, F. Santoni Department of Astronautics, Electric and Energy Engineering, University Sapienza of Rome, via Eudossiana 18, 00184 Rome, Italy Abstract The growing quantity of debris in Earth orbit poses a danger to users of the orbital environment, such as spacecraft. It also increases the risk that humans or manmade structures could be impacted when objects reenter Earth’s atmosphere. During the design of a spacecraft, a requirement may be specifi d for the s rviv-ability of the spacecraft again t Meteor id / Orbital Debris (M/OD) impacts throughout the mission; further-more, the structure of a spacecraft is designed to insure its integrity during the launch and, if it is reusable, during descent, re-entry and landing. In addition, the structure has to provide required stiffness in order to allow for exact positioning of experiments and antennas, and it has to protect the payload against the space environment. In order to decrease the probability of spacecraft failure caused by M/OD, space maneuver is needed to avoid M/OD if the M/OD has dimen sions larger than 10cm, but for M/OD with dimensions less than 1cm M/OD shields are needed for spacecrafts. It is therefore necessary to determine the impact-related failure mechanisms and associated ballistic limit equations (BLEs) for typical spacecraft components and subsys-tems. The methods that are used to obtain the ballistic limit equations are numerical simulations and la borato-ry experiments. In order to perform an high energy ballistic characterization of layered structur s, a new ad-vanced electro magnetic accelerat r, called railgun, has been as embled a d tun d. A railgun is an electrically pow red electromagnetic pr jectile launcher. Such device is made up of a pair of par llel con ucting rails, which a sliding metallic armature is a celerated along by the electromagn tic ffect (Loren z force) of a cur-rent that flows down one rail, into t e armature and then back along the other rail, thanks to a high power pulse given by a bank of capacitors. A tu able power supplier is used to set the capacit rs charging voltage at the desired level: in this way the Rail Gun energy can be tuned as a fu ction of the desi d bullet velocity. This facility is able to analyze both low and high velocity impacts. A numerical simulation is also perfor ed by using the Ansys Autodyn code in order to analyze the damage. The experimental results and numerical simulations show that the railgun-device is a good candidate to perform impact testing of materials in the space debris energy range. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy A new advanced railgun system for debris impact study A. Vricella*, A. Delfini, A. Pacciani, R. Pastore, D. Micheli, G. Rubini, M. Marchetti, F. Santoni Department of Astronautics, Electric and Energy Engineering, University Sapienza of Rome, via Eudossiana 18, 00184 Rome, Italy Abstract T growing q antity f debris in Earth orbit poses a danger to users of the orbital vironment, such as spacecraft. It also increases the risk that humans or manmade structur s c uld be impacted whe objects reenter Earth’s tmosphere. Dur ng th design of space raft, a requirem nt may be specified for the s rviv-ability of the spac craft against Meteoroid / Orbital Debris (M/OD) impacts throughout the missio ; further-more, the structure of a spacecraft is designed to insur its int grity during the launch and, if it is reusable, during descent, r -entry and la ding. In addition, the structure has to provide required stiffness in order t allow for ex ct positi ning of experiments and antennas, and it has to protect the payload against the space environment. In or er to decrease the probability of spacecraft failure caus d by M/OD, space aneuver i n e ed to avoid M/OD if the M/OD has dimen sions l rger than 10cm, but for M/OD with dimensions less than 1cm M/OD shields are needed for spacecraf s. It is ther fore necessary to determine the i pact-related failure mechanisms and associated ballistic limit equations (BLEs) for typical spacecraft components and subsys-tems. The methods that are used to obta n t e ballistic limit equations are numerical simul tions and la borato-ry exp riments. In order to perfor an high energy ballistic characterizatio of layere structu s, a new ad-vanced electro magnetic acceler tor, called railgun, h been assembled a tuned. A railgun is n elect ic lly owered el ctromagnetic projectile launcher. Such d vic is made up of a p ir parallel conducting rails, which sl ding metallic a mature is acc lerated along by the lectromagn tic effect (Lorentz force) of a cur- ent that fl ws dow on rail, into the a mat r and then back long the other rail, ha ks to a high pow r pulse given by a bank f capacitors. A able power supp ier is used to set the capacitors charg ng voltag at the desired lev l: i this way th Rail Gun en rgy can be tuned as a function o the desired bullet velocity. This facility is able to analyze both low and high veloc ty impact . A numerical simulation is lso performed by using the An ys Autodyn code in order to analyze the damage. The experim ntal r sults and nume ical simulations show that the railgun-device is a good candidate to perform impact te ting of materials in th space debris energy range. © 2017 The Authors. Published by Els vier B.V. Peer-review under responsibility of the Scientific Com ittee of IGF Ex-Co. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 The Auth rs. 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 IGF Ex-Co. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +39-349 4469058. E-mail address: antonio.vricella@uniroma1.it * Correspon ing author. Tel.: +39-349 4469058. E-mail address: antonio.vricella@uniroma1.it

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsev er B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 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 IGF Ex-Co. 10.1016/j.prostr.2017.04.044