PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1488–1493 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect 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 effects on Structural Integrity Fracture and microstructural study of bovine bone under mixed mode I/II loading MRM. Aliha a, *, S. Bagherifard b , Sh. Akhondi c , SS. Mousavi a , A. Mousavi a , H. Parsania a a Welding and Joining Research Center, Iran University of Science and Technology (IUST), Narmak-16846-13114, Tehran, Iran. b Politechnico di Milano, Department of Mechanical Engineering, Via. G. La Masa, 1, 20156 Milano, Italy c School of Industrial and Information Engineering, Polytechnic University of Milan, Milano, 20156, Italy Understanding the fracture behavior and associated crack gr wth mechanism in bone material is an important issue for biomechanics and biomaterial researches. Fracture of bone often takes place due to complex loading conditions which result in combined tensile-shear (i.e. mixed mode) fracture mechanism. Several parameters such as loading type, applied loading direction relative to the bone axis, loading rate, age and etc., may affect the mixed mode fracture resistance and damage mechanism in such materials. In this research, a number of mixed mode I/II fracture experiments are conducted on bovine femur bone using a sub-sized test configuration called “ compact beam bend (CBB) ” specimen to investigate the fracture toughness of bone under different mode mixities. The specimen is rectangular beam containing a mid-edge crack that is loaded by a conventional three point bend fixture. The results showed the dependency of bone fracture toughness on the state of mode mixity. The fracture surfaces of broken CBB specimens under ifferent loading conditions were studied via scanning electron microscopy (SEM) observations. Fracture surface of all investi ate c ses (i.e. pure mode I, pur mode II and mixed mode I/II) exhibited smooth patterns demonstrating brittle fracture of bovine f mur. The higher density o vascular channels and micro-cra ks initiated in the weakened area surrounded b econdary osteons were found to b the main cause of the decreased bo e resistance against crack gr wth an brittle fr cture. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Fracture and microstructural study of bovine bone under mixed mode I/II loading MRM. Aliha a, *, S. Bagherifard b , Sh. Akhondi c , SS. Mousavi a , A. Mousavi a , H. Parsania a a Welding and Joining Research Center, Iran University of Science and Technology (IUST), Narmak-16846-13114, Tehran, Iran. b Politechnico di Milano, Department of Mechani al Engi eering, Via. G. La Masa, 1, 20156 Milano, Italy c School of Industrial and Information Engineering, Polytechnic Un versity of Mil n, Milano, 20156, Italy Abstract Understanding the fracture behavior and associated crack growth mechanism in bone material i an important issue f r biomechanics and biomaterial researches. Fracture of bone often takes place due to complex loading conditions which result in co bined tensile-shear (i.e. mixed mod ) fracture mecha ism. Several parameters such as loading type, applied loading directio relative to the bone xis, loading rate, age and tc., m y affect the mixed mode fracture resistance and damage mechanism i such materials. In this research, a number of mixed mode I/II fracture experiments re conducted on bovine femur bone u ing a b-sized test co figuration alled “ compact beam ben (CBB) ” specimen to i vestigate the fracture toughness of bone u der different mode mixities. The specimen is rectangular beam containing a mid-edge crack that is loaded by a conventional thre - point bend fixture. The results showed the dependency of bone fract re toughn ss on the state of mode mixity. The fracture surfaces of broken CBB pecimens under differ nt loading conditions were tudied via scanning electron microscopy (SEM) obs rv ti ns. Fracture surface of all i vestigated cases (i.e. pur ode I, pure mode II nd mixed mode I/II) exhibited smooth pa t rns d monstrating brittle fracture of bovin femu . Th higher density of vascular ch nels and icro-cra ks initiated in the weakene area urrounded by se ondary osteons were foun to be the main cause o the decreased b ne esistance ag inst crack growth and brittle fracture. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Bovine femur, Compact beam bend specimen, Mixed mode fracture, SEM analysis Keywords: Bovine femur, Compact beam bend specimen, Mixed mode fracture, SEM analysis

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

* Corresponding author. Tel.: +98-21-73225031; fax: +98-21-73225098. E-mail address: mrm_aliha@iust.ac.ir * Corresponding author. Tel.: +98-21-73225031; fax: +98-21-73225098. E-mail address: mrm_aliha@iust.ac.ir

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 o ganizers.

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

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.306