PSI - Issue 8

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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. ∗ Corresponding author. Tel.: + 39 0672597124. E-mail address: biancolini@ing.uniroma2.it 2210-7843 c 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. ∗ Corresponding author. Tel.: + 39 0672597124. E-mail address: biancolini@ing.uniroma2.it 2210-7843 c 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 Copyright  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis 10.1016/j.prostr.2017.12.038 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. Copyright © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6–9 September 2017, Pisa, Italy Shape optimization using structural adjoint and RBF mesh morphing C. Groth a , A. Chiappa a , M.E. Biancolini a, ∗ a Department of Enterprise Engineering - University of Rome Tor Vergata, Via del Politecnico, 1, 00133, Rome, Italy Abstract Adjoint solvers are acquiring nowadays a growing importance in shape optimization especially when dealing with fluid dynamic applications; their use for structural optimization is however still limited. In this work an optimization workflow based on the synergic use of a structural continuum-discrete adjoint variable solver and the commercial morpher RBF Morph TM is presented. Shape sensitivity information with respect to the objec ive f ncti n is exported as deformation maps on the interested geometry and transferred to the morpher that, after a proper filtering and setup, allows to update automatically the numerical grid. By employing a gradient based logic it is finally possible to achieve an evolutionary optimization. The proposed method e ff ectiveness is shown with two examples: a cantilever beam and a structural bracket. c 2017 The Authors. Publi hed by Elsevier B.V. r ie unde responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: Adjoint; Sensitivity; FEM; Shape optimization; RBF 1. Intro uction During the years numerical analysis assumed a growing importance in the engineering practice, obtaining a crucial and irreplaceable role in the design phase. Complex systems and physics can be studied in a short amount of time, foreseeing their behavior with great accuracy. Having the ability to study faithfully a system - being it mechanic, fluid dynamic or dominated by other physics - means also to be able to evaluate the influence of its boundary conditions by examining their e ff ect before and after their variation. The main problem of understanding how to apply these variations in the most e ffi cient way however re ains, being relevant and di ffi cult especially when dealing with a shape change. In engineering applications the most employed methods are zero order ones. While carrying a set of useful features, such as their ability to reach a global optimum and the relatively easy implementation, their cost can be unbearable when dealing with an high number of objective functions and parameters. This property, at the price of finding a local optimum, is covered by optimization methods based on the gradient, using in an iterative and evolutionary fashion the system sensitivities with respect to a parameter; these information, comparable with the gradient of the response AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6–9 September 2017, Pisa, Italy Shape opti ization using structural adjoint and RBF mesh morphing C. Groth a , A. Chiappa a , M.E. Biancolini a, ∗ a Department of Enterprise Engineering - University of Rome Tor Vergata, Via del Politecnico, 1, 00133, Rome, Italy Abstract Adjoint solvers are acquiring nowadays a growing importance in shape optimization especially when dealing with fluid dynamic applications; their use for structural optimization is however still limited. In this work an optimization workflow based on the synergic use of a structural continuum-discrete adjoint variable solver and the commercial morpher RBF Morph TM is presented. Shape sensitivity information with respect to the objective function is exported as deformation maps on the interested geometry and transf rred to the morpher that, after a proper filteri g and setup, allows t update automatically the numerical grid. By employing a gradient based logic it is finally possible to achieve an evoluti nary optimization. The proposed method e ff ectiveness is shown with two examples: a cantilever beam and a structural bracket. c 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: Adjoint; Sensitivity; FEM; Shape optimization; RBF 1. Introduction During the years num rical analysis assumed a growing importance in the engineering practice, obtaining a crucial and irreplaceable role in the design phase. Complex systems and physics can be studied in a short amount of time, foreseeing their behavior with great accuracy. Having the ability to study faithfully a system - being it mechanic, fluid dynamic or dominated by other physics - means also to be able to evaluate the influence of its boundary conditions by examining their e ff ect before and after their variation. The main problem of understanding how to apply these variations in the most e ffi cient way however remains, being relevant and di ffi cult especially when dealing with a shape change. In engineering applications the most employed methods are zero order ones. While carrying a set of useful features, such as their ability to reach a global optimum and the relatively easy implementation, their cost can be unbearable when dealing with an high number of objective functions and parameters. This property, at the price of finding a local optimum, is covered by optimization methods based on the gradient, using in an iterative and evolutionary fashion the system sensitivities with respect to a parameter; these information, comparable with the gradient of the response © 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.