PSI - Issue 12

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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. AIAS 2018 International Conference on Stress Analysis Design of a new intervertebral disc prosthesis: a numerical approach Guido La Rosa*, Graziano Basile, Giovanna Fargione, Fabio Giudice DICAR, University of Catania, Via S. Sofia 64, 95123 Catania, Italy Abstract In the degenerative disc disease, an alternative treatment to the traditional arthrodesis, consisting in the fusion of the two adj cent vertebral bodies, is the artificial intervertebral disc. The advantage of an artificial intervertebral disc is that the d.o.f. of the vertebral segment can be saved and the mobility of the spine could be almost restored. Many solutions were proposed in the last decades, most of them consisting in metallic rigid joints able to assure the mobility and to maintain the correct distance between the vertebrae but subject to corrosion, wear and interface problems due to the different stiffness with the biological tissues. Purpose of this paper is the design of a prosthetic device substituting the disc to be placed in the intervertebral zone. Different types of artificial prostheses have been proposed by the authors, based on similarity with physiological discs, then with a central part (nucleus) made of hyperelastic material and an outer containment frame (annulus) consisting of a plastic material with a stiffness high enough to assure the reaction force and to avoid large radial displacements. In our solutions, the external parts (annulus and plates) were modeled by HDPE and the inner part (nucleus) by silicone and hydrogel. All the materials are highly biocompatible. The intention of the authors, moreover, is to permit an easier surgical technique. The prosthesis, in fact, could be mounted void of the nucleus, allowing an easier placement, and filled only after the frame insertion, by injecting the silicone through a syringe. The nucleus was modeled by the Mooney-Rivlin parameters related to elastomers, being the disc subject to large deformations that the materials have to be able to withstand in elastic conditions. The discs are subjected to compressive loads either in the mounting phase or, after the silicone filling, due to the physiological loads. © 2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. © 2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. AIAS 2018 International Conference on Stress Analysis Design of a new intervertebral disc prosthesis: a numerical approach Guido La Rosa*, Graziano Basile, Giovanna Fargione, Fabio Giudice DICAR, University of Catania, Via S. Sofia 64, 95123 Catania, Italy Abstract In the degenerative disc disease, an alternative treatment to the traditional arthrodesis, consisting in the fusion of the two adjacent vertebral bodies, is the artificial intervertebral disc. The advantage of an artificial intervertebral disc is that the d.o.f. of the vertebral segment can be saved and the mobility of the spine could be almost restored. Many solutions were proposed in the last decades, most of them consisting in metallic rigid joints able to assure the obility and to maintain the correct distance between the vertebrae but subject to corrosion, wear and nterface problem d e to the different stiffnes with the biological tissues. Purpose of this paper is the design of a prosthetic device substituting the disc to be placed in the intervertebral zone. Different types of artificial prostheses have been proposed by the authors, based on similarity with physiological discs, then with a central part (nucleus) made of hyperelastic material and an outer containment frame (annulus) consisting of a plastic material with a stiffness high enough to assure the reaction force and to avoid large radial displacements. In our solutions, the external parts (annulus and plates) were modeled by HDPE and the inner part (nucleus) by silicone and hydrogel. All the materials are highly biocompatible. The intention of the authors, moreover, is to permit an easier surgical technique. The prosthesis, in fact, could be mounted void of the nucleus, allowing an easier placement, and filled only after the frame insertion, by injecting the silicone through a syringe. The nucleus was modeled by the Mooney-Rivlin parameters related to elastomers, being the disc subject to large deformations that the materials have to be able to withstand in elastic conditions. The discs are subjected to compressive loads either in the mounting phase or, after the silicone filling, due to the physiological loads. © 2018 The Authors. Published by Elsevier B.V. This is n open access art cle u d the CC BY-NC-ND license (http://cre tivecommons.org/licenses/by-nc-nd/3.0/) Peer-review under responsibility of the Scientific ommitte o AIAS 2018 Internation l Conference on Stress Analysis.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Intervertebral disc; Hyperelasticity; Spine; Disc prosthesis. Keywords: Intervertebral disc; Hyperelasticity; Spine; Disc prosthesis.

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

* Corresponding author. Tel.: +39 095 7382413. E-mail address: glarosa@dii.unict.it * Corresponding author. Tel.: +39 095 7382413. E-mail address: glarosa@dii.unict.it

2452-3216 © 2018 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/3.0/) Peer-revi w u er responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. 2452-3216 © 2018 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/3.0/) Peer-review u der responsibility of t Scientific ommittee of AIAS 2018 Internati al 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  2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. 10.1016/j.prostr.2018.11.088