PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 787–792 Available online at www.sciencedirect.com Structural Integrity Procedia 0 (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 Phase-Field Modelling of Crack Propagation in Anisotropic Polycrystalline Materials Zhengkun Liu a, ∗ , Daniel Juhre a a Institute of Mechanics, Otto von Guericke University Magdeburg, Universita¨ tsplatz 2, 39106 Magdeburg, Germany Abstract Nowadays, products consisting of polycrystalline materials have been widely used in engineering applications, e.g. automobile and renewable energy. The macroscopic defects are generally strongly influenced by the fracture behavior of the polycrystalline materials at the meso- and microscopic level. In this paper, the proposed phase-field model for anisotropic fracture, which accounts for the preferential cleavage directions within each randomly oriented crystal, as well as an anisotropic material behavior with cubic symmetries, has been used to simulate the complex crack pattern in solar-grade polycrystalline silicon in a robust and straightforward manner. Furthermore, multi-field coupled finite element problems are performed with monolithic solution schemes. A representative numerical example for crack propagation in polycrystals is carried out. Finally, a summary of the numerical results in polycrystalline materials is presented and an outlook for next work steps is given. c 2018 The Authors. Publishe by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Finite elements; Phase-fie d model; Anisotropic fracture; Solar-grade polycrystalline silicon 1. Introduction Until this day, many components were designed by using polycrystalline materials, e.g. ceramics and metals. At the meso- and microscopic level, each crystal has di ff erent materials properties. Microscopic material properties of polycrystalline material can influence the mechanical behavior of material at the macroscale level and hence it is necessary to analyse the mechanical performances of polycrystals at the meso- and microscopic level. Generally, conventional methods of strength calculation cannot be used to simulate polycrystal defects. Phase-field method has been recently used to simulate crack nucleation, curved crack propagation, crack kinking and branching and merging of cracks with significant success (Ambati et al. (2014)). In this method, the sharp crack is replaced by the di ff use crack which is the so-called phase-field parameter s that varies smoothly from 1 (intact material) to 0 (fully cracked material). In this paper, the phase-field approach for brittle fracture in anisotropic materials is firstly introduced. Then, illustrative numerical examples considering crack propagation in solar-grade polycriytalline silicon. Moreover, the ECF22 - Loading and Environmental e ff ects on Structural Integrity Phase-Field odelling of Crack Propagation in Anisotropic Polycrystalline aterials Zhengkun Liu a, ∗ , Daniel Juhre a a Institute of Mech nics, Otto von Guerick University Magdeburg, Universita¨ tsplatz 2, 39106 Magdeburg, Germany Abstract Nowadays, products consisting of polycrystalline materials have been widely used in engineering applications, e.g. automobile and renewable energy. The macroscopic defects are generally strongly influenced by the fracture behavior of the polycrystalline materials at the meso- and microscopic level. In this paper, th proposed phase-fiel model for anisotropic fracture, which accounts for the preferential cleavage directions within each randomly oriented crystal, as well as an anisotropic material behavior with cubic symmetries, has been used to simulate the complex crack pattern i solar-gra polycrystalline silicon in a robust and straightforward manner. Furthermore, multi-field coupled finite element problems are performed with monolithic solution schemes. A representative numerical example for crack propagation in polycrystals is carried out. Finally, a summary of the numerical results in polycrystalline materials is presented and an outlook for next work steps is given. c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Finite elements; Phase-field model; Anisotropic fracture; Solar-grade polycrystalline silicon 1. Introduction Until this day, many components were designed by using polycrystalline materials, e.g. ceramics and metals. At the meso- and microscopic level, each crystal has di ff erent materials properties. Microscopic material properties of polycrystalline material can influence the mechanical behavior of material at the macroscale level and hence it is necessary to analy e the mechanical performances of polycrystals at the meso- and microscopic level. Generally, conventional methods of strength calculation cannot be used to simulate polycrystal defects. Phase-field method has been recently used to simulate crack nucleation, curved crack propagation, crack kinking and branching and merging of cracks with significant success (Ambati et al. (2014)). In this method, the sharp crack is replaced by the di ff use crack which is the so-called phase-field parameter s that varies smoothly from 1 (intact material) to 0 (fully cracked material). In this paper, the phase-field approach for brittle fracture in anisotropic materials is firstly introduced. Then, illustrative numerical examples considering crack propagation in solar-grade polycriytalline silicon. Moreover, the © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 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. Tel.: + 49 391 52918; fax: + 49 391 12439. E-mail address: zhengkun.liu@ovgu.de ∗ Corresponding author. Tel.: + 49 391 52918; fax: + 49 391 12439. E-mail address: zhengkun.liu@ovgu.de

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 Els vier 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 organizers. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.152