PSI - Issue 13

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 13 (2018) 753–762 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 0– 0 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 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. ECF22 - Loading and Environmental e ff ects on Structural Integrity Hydrogen Embrittlement in Advanced High Strength Steels and Ultra High Strength Steels: a new investigation approach Antonello Cherubini, Linda Bacchi, Serena Corsinovi, Marco Beghini, Renzo Valentini University of Pisa, Largo Lucio Lazzarino 2, Pisa, Italy Abstract In order to reduce CO 2 emissions and fuel consumption, and to respect current environmental norms, the reduction of vehicles weight is a primary target of the utomotive indu ry. Advanced High Strength St els (AHSS) and Ultra High Strength Steel (UHSS), which present excellent mechanical properties, are consequently increasingly used in vehicle manufacturing. The in creased strength to mass ratio compensates the higher cost per kg, and AHSS and UHSS are proving to be cost-e ff ective solutions for the body-in-white of mass market products. In particular, aluminized boron steel can be formed in complex shapes with press hardening processes, acquiring high strength without distortion, and increasing protection from crashes. On the other hand, its characteristic martensitic microstructure is sensi tive to hydrogen delayed fracture phenomena and, at the same time, the dew point in the furnace can produce hydrogen consequently to the high temperature reaction between water and aluminum. The high temperature also promotes hydrogen di ff usion through the metal lattice under the aluminum-silicon coating, thus increasing the di ff usible hydrogen content. However, after cooling, the coating acts as a strong barrier preventing the hydrogen from going out of the microstructure. This increases the probability of delayed fracture. As this failure brings to the rejection of the component during production, or, even worse, to the failure in its operation, di ff usible hydrogen absorbed in the component needs to be monitored during the production process. For fast and simple measurements of the response to di ff usible hydrogen of aluminized boron steel, one of the HELIOS inno vative instruments was used, HELIOS II. Unlike the Devanathan cell that is based on a double electrochemical cell, HELIOS II is based on a single cell coupled with a solid-state sensor. The instrument is able to give an immediate measure of di ff usible hydrogen content in sheet steels, semi-products or products, avoiding tim -consuming specimen pall dium coating with guided pr c d re that requires virtually zero training. Two examples of di ff usible hydrogen analyses are given for Usibor R 1500-AS, one before hot stamping / quenching, and one after hot stamping, suggesting that the increase in the number of dislocations during hot stamping could be the main responsible for the low r appar nt di ff usivity of hydrogen. c 2018 The Author . Published by Elsevi r B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen; HE; HSSA; Advanced High Strength Steel; Desorption; HELIOS; © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental e ff ects on Structural Integrity Hydrogen Embrittlement in Advanced High Strength Steels and Ultra High Strength Steels: a new investigation approach Antonello Cherubini, Linda Bacchi, Serena Corsinovi, Marco Beghini, Renzo Valentini University of Pisa, Larg Lucio Lazzarino 2, Pisa, Italy Abstract In order to reduce CO 2 missions and fuel consumption, and to respect current environmental norms, the reduction of vehicles weight is a primary target of the automotive industry. Advanced High Strength Steels (AHSS) and Ultra High Strength Steel (UHSS), which present excellent mechanical properties, are consequently increasingly used in vehicle manufacturing. The in creased strength to mass ratio compensates the higher cost per kg, and AHSS and UHSS are proving to be cost-e ff ective solutions for the body-in-white of mass market products. In particular, aluminized boron steel can be formed in complex shapes with press hardening processes, acquiring high strength without distortion, and increasing protection from crashes. On the other hand, its characteristic martensitic microstructure is sensi tive to hydrogen delayed fracture phenomena and, at the same time, the dew point in the furnace can produce hydrogen consequently to the high temperature reaction between water and aluminum. The high temperature also promotes hydrogen di ff usion through the metal lattice under the aluminum-silicon coating, thus i creasing the di ff usible hydrogen content. However, after cooling, he coating cts as a strong bar ier prev nting the hydrogen from goi g out of the microstructure. This increases the probability of delayed fracture. As this failure brings to th rejection o th component during production, or, ev n worse, to the fai ure in its operation, di ff usible hydrogen absorb d in the compon nt needs to be monitored during the product on process. For f st and simpl measurements of the response to di ff usible hydrogen o aluminized boron steel, one f th HELIOS inn - vativ instruments was used, HELIOS II. Unlike the Dev nath c ll that is based on double electrochemic l cel , HELIOS II is based on a single cell coupled with a solid-stat se sor. The instrument is able to give an immediate measure of di ff usible hydrogen content in sheet steels, semi-products or products, avoiding time-consuming specim n palladium coati g with a guided procedure that requires virtually zero trai ing. Two examples of di ff usible hydrogen analyses are given for Usibor R 1500-AS, one before hot stamping / quenching, and one after hot stamping, suggesting that the increase in the number of dislocations during hot stamping could be the main responsible for the lower apparent di ff usivity of hydrogen. c 2018 The Authors. Published by Elsevier B.V. P r-review under responsibility of the ECF22 organizers. Keywords: Hydrogen; HE; HSSA; Advanced High Strength Steel; Desorption; HELIOS; © 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.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt ∗ Corresponding author: Renzo Valentini E-mail address: renzo.valentini@unipi.it ∗ Corresponding author: Renzo Valentini E-mail address: renzo.valentini@unipi.it

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the ECF22 orga izers. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.125