PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 461–468 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t gri y 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 Bending fracture of Co-Cr dental bridges, produced by additive technologies: experimental investigation Tsanka Dikova* Faculty of Dental Medicine, Medical University of Varna, 84 Tsar Osvoboditel Blvd, Varna 9000, Bulgaria Abstract The aim of this paper is to investigate the fracture during bending test of Co-Cr dental bridges, produced by additive technologies. Three groups of samples (four-part dental bridges from 1-st premolar to 2-nd molar) were produced by conventional casting with handmade wax t erns, casting with 3D printed patterns and selective laser m lting (SLM). The bending test was done using Tir Test 2300 SE/50 kN machine and especially designed appliance, ensuring loading closest to the actual during masticatory process. The loadings until cracking and fracture were evaluated. The fract r d surfaces were investigated by ptical microscopy. It was established that the SLM dental bridges of Co212-f alloy are being destroyed in 9.255 kN loading, which is commensurable with that for cracking of the samples, cast from Biosil-F alloy – 9.820 kN in conventional casting and 10.171 kN in casting with 3D printed patterns. The destruction of the cast Co-Cr bridges consists of three stages – crack initiation in the most loaded area, its growth and final fracture, while the destruction of the SLM samples suddenly occurs because of a network of cracks in the entire volume. The destruction type of the Co-Cr bridges, produced by SLM and casting, is identical - ductile, but the way that fracture occurs is different due to their structure. T e specific layered macrostructure, the fine microstructure with dendritic morphology, the phase composition – the presence of ε-phase and the typical defects of the SLM Co-Cr alloy defi e the fract re mechanism duri g bending. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Co-Cr alloys; dental bridges; additive technology; selective laser melting; casting; bedning fracture 1. Introduction Dental constructions work under conditions f variable stresses in a highly aggressive environment - the saliva. Their durability is defined by the mechanical properties and corrosion resistance of the materials used. Co-Cr dental alloys are most commonly used for manufacturing of metal infrastructures for prosthetic constructions because of © 2018 The Authors. P blished by Elsevi r B.V. Peer-review und r responsibility of the ECF22 organiz rs. ECF22 - Loading and Environmental effects on Structural Integrity Bending fracture of Co-Cr dental bridges, produced by additive technologies: experimental investigation Tsanka Dikova* Faculty of Dental Medicine, Medical University of Varna, 84 Tsar Osvoboditel Blvd, Varna 9000, Bulgaria Abstract The aim of this paper is to investigate the fracture during bending test of Co-Cr dental bridges, produced by additive technologies. ree groups of samples (four-part dental bridges from 1-st premolar to 2-nd molar) were produced by conventional casting with handmade wax patterns, casting with 3D printed patterns and s lec ive laser melting (SLM). The b nding test was done usi Tira Test 2300 SE/50 kN machine and especially designed applia c , nsuri g loading closest to the actual during masticatory process. he loadings until cracking and fr cture were evaluated. The fractured surfaces were investigated by optical microscopy. It was established th t the SLM dental bridges of Co212-f alloy are being destroyed in 9.255 kN loading, which is commensurable with that for cracking of the samples, cast from Bi sil-F alloy – 9.820 kN in conventional casting and 10.171 kN in asting with 3D printed patterns. The destruction of the cast Co-Cr bridges consists of three stages – crack initiation in the most loaded area, its growth and final fracture, while the destruction of the SLM samples suddenly occurs because of a network of cracks in the entire volume. The destruction type of the Co-Cr bridges, produced by SLM and casting, is identical - ductil , but the w y that fracture occurs is different due to their structure. The specific layered macrostructure, the fi e microstructure with dendritic morphology, the phase composition – the presence of ε-phase and the typical d fects of the SLM Co-Cr alloy define the fracture mechanism during bending. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Co-Cr alloys; dental bridges; additive technology; selective laser melting; casting; bedning fracture 1. Introduction Dental constructions work under conditions of variable stresses in a highly aggressive environment - the saliva. Their durability is defined by the mechanical properties and corrosion resistance of the materials used. Co-Cr dental alloys are most commonly used for manufacturing of metal infrastructures for prosthetic constructions because of © 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.: +359-899-883-125; E-mail address: tsanka_dikova@abv.bg * Corresponding author. Tel.: +359-899-883-125; E-mail address: tsanka_dikova@abv.bg

* 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 responsibility of the ECF22 organizers.

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.2018.12.077