PSI - Issue 2_B

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2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 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/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.076 ∗ Per Ståhle. Tel.: + 46-70-553-9492 E-mail address: per.stahle@solid.lth.se 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. With the increasing need for green energy, hydrogen fuel cell technologies are used as renewable energy resources. As a consequence secure vessels for transport and storage of liquid hydrogen is required. Much of the e ff orts are done to the selection and production of secure transportation and storage materials. However, the e ff ect of the hydrogen to the transportation vessels are unavoidably associated with interaction between the hydrogen and the base material. In nuclear power production metallic zirconium is exposed to hydrogen as it used extensively as structural support for the fuel and the control rods. Zirconium forms brittle hydrides in hydrogen environments, which may case serious prob lems. Other hydride forming metals of practical interest include magnesium, titanium, hafnium. In many applications of these metals, the formation of hydride is considered to be a major life limiting factor. ∗ Per Ståhle. Tel.: + 46-70-553-9492 E-mail address: per.stahle@solid.lth.se 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. When structural materials are exposed to a long term hydrogen environment they may interact with hydrogen, and cause various kinds of structural damages due to metal degradation. The interaction and damage of hydrogen depend on a range of conditions. In the metals that form hydride, the precipitation of small and local amounts of hydrides strongly a ff ect the local mechanical properties and the over all integrity of the entire structure. With the increasing need for green energy, hydrogen fuel cell technologies are used as renewable energy resources. As a consequence secure vessels for transport and storage of liquid hydrogen is required. Much of the e ff orts are done to the selection and production of secure transportation and storage materials. However, the e ff ect of the hydrogen to the transportation vessels are unavoidably associated with interaction between the hydrogen and the base material. In nuclear power production metallic zirconium is exposed to hydrogen as it used extensively as structural support for the fuel and the control rods. Zirconium forms brittle hydrides in hydrogen environments, which may case serious prob lems. Other hydride forming metals of practical interest include magnesium, titanium, hafnium. In many applications of these metals, the formation of hydride is considered to be a major life limiting factor. ∗ Per Ståhle. Tel.: + 46-70-553-9492 E-mail address: per.stahle@solid.lth.se 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Interface instabilities of growing hydrides Per Ståhle ∗ , Wureguli Reheman Div. of Solid Mechanics, Lund Institute of Technology, Lund, Sweden Abstract Formation of metal hydrides is a serious complication that occur whe hydride forming metals such as zirconium, niobium, vana dium and magnesium are exposed to long term hydrogen environment. The main concern is that the hydride, as being a brittle material, has very poor fracture mechanical properties. Formation of hydride is associated with transportation of hydrogen along the gradients of increasing hydrostatic stress, which leads to crack tips and other stress concentrators, where it forms the hydride. In the present study the thermodynamics of the evolving hydrides is studied. The process is driven by the release of free strain, chemical, and gradient energi s. A phase field model is used to capture the driving forces that the release of the free energy causes. The study gives the conditions that lead to hydride advancement versus retreat and under which conditions the metal-hydride in terface becomes unstable and develops a waviness. The spatial frequency spectrum leading to instability is found to depend on the ratio of the elastic strain energy density and parameters related to the interface energy. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Metal hydride; Growth; Platelets 1. Introduction When structural materials are exposed to a long term hydrogen environment they may interact with hydrogen, and cause various kinds of structural damages due to metal degradation. The interaction and damage of hydrogen depend on a range of conditions. In the metals that form hydride, the precipitation of small and local amounts of hydrides strongly a ff ect the local mechanical properties and the over all integrity of the entire structure. With the increasing need for green energy, hydrogen fuel cell technologies are used as renewable energy resources. As a consequence secure vessels for transport and storag of liquid hydrogen is required. Much of the e ff orts are done to the selection and production of secure transportation and storage materials. However, the e ff ect of the hydrogen to the transportation vessels are unavoidably associated with interaction between the hydrogen and the base material. In nuclear power production metallic zirconium is exposed to hydrogen as it used extensively as structural support for the fuel and the control rods. Zirconium forms brittle hydrides in hydrogen environments, which may case serious prob lems. Other hydride forming metals of practical interest include magnesium, titanium, hafnium. In many applications of these metals, the formation of hydride is considered to be a major life limiting factor. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Int face instabilities of growing hydrides Per Ståhle ∗ , Wureguli Reheman Div. of Solid Mechanics, Lund Institute of Technology, Lund, Sweden Abstract Formation of metal hydrides is a s rious omplication that occur when hydride forming metals such as zirconium, niobium, vana dium and magnesium are exposed to long term hydrogen environment. The main con ern is hat the hydride, as being a b ttle material, has very poor fracture mechanical properties. Format on of hydr de is associated with tra sportation of hydrogen alo g t gradients of increasi g hydrostatic tress, which lead to crack tips and other stress concentrators, where it forms the hydride In the present tudy the thermodynamics f the evolving hydrides is studied. The proc ss is drive by the releas of free strai , chemical, and gradient energies. A phase field model is used to capt re the driving forces that the release of the free energy causes. The study gives the co ditions that lead to hydrid advancement versus etreat and under which conditions the metal-hydride in terface becomes unstable and develop a waviness. The spatial frequency spectrum leading to instability is found to depend on the ratio of the elastic strain energy density and parameters related to the interface energy. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Metal hydride; Growth; Platel ts 1. Introduction When structural materials are exposed to a long term hydrogen environment they may interact with hydrogen, and cause various kinds of structural damages due to metal degradation. The interaction and damage of hydrogen depend on a range of conditions. In the metals that form hydride, the precipitation of small and local amounts of hydrides strongly a ff ect the local mechanical properties and the over all integrity of the entire structure. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Interface instabilities of growing hydrides Per Ståhle ∗ , Wureguli Reheman Div. of Solid Mechanics, Lund Institute of Tec nology, Lund, Sweden Abstract Formation of metal hydrides is a serious complication that occur when hydride forming metals such as zirconium, niobium, vana dium and magnesium are exposed to long term hydrogen enviro ment. The main concern is that the hydride, as being a brittle material, has very poor fracture mechanical properties. Formation of hydride is associated with transportation of hydrogen along the gradients of increasing hydrostatic stress, which leads to c ack tips and oth r stress concentrators, where it forms the hydride. In the present study the thermodynamics of the evolving hydrides is studied. The process is driven by the release of free strain, chemical, and gradient energies. A phase field model is used to capture the driving forces that the release of the free energy causes. The study gives the conditions that lead to hydride advancement versus retreat and under which conditions the metal-hydride in terface becomes unstable and develops a waviness. The spatial frequency spectrum leading to instability is found to depend on the ratio of the elastic strain energy density and parameters related to the interface energy. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Metal hydride; Growth; Platelets 1. Introduction Copyright © 2016 The Authors. Published by Elsevier B.V. This is an pen access rticle under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). P eview under esponsibility of the Scientific Committee of ECF21. © 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