PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Available o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 14 (2019) 234–241 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Extraction of Opening and Closing States of Cracked Structure using Adaptive Volterra Filter Model J. Prawin a , A. Rama Mohan Rao b a Scientist, CSIR Structural Engineering Research Centre, Chennai - 600113, INDIA b Chief Scientist, CSIR Structural Engineering Research Centre, Chennai - 600113, INDIA Abstract Fatigue cracks often exist in structures during the service life of the structure and need to detect at its earliest stage before it leads to catastrophic failure. The fatigue breathing crack problem exhibits an instantaneous change in the stiffness of the structure due to change in th state of the cracked domain from open to close and vice versa. Theref re these fatigue cracks exhibit breathing like phenomena, hence widely referred as breathing cracks. The present work attempts to separate the opening and closing of the cracked structure from the global response using adaptive Volterra Filter Model. Adaptive Volterra Filter model is a generalization of the linear convolution and the impulse response function to nonlinear structures in discrete form. The dynamical properties of the nonlinear system in the Volterra series representation or adaptive Volterra Filter Model are completely characterized by a sequen e of multi-dimensional weighting functi n called Volterra kernels. These Volterra kernels are the backbon of adaptive Volterra filter approa h in n nlinear analysis nd system identi ication and diverse rang of t chniques are reported in the literature for Volterra ker el esti ation. Adaptive Volterra series based Least square is used in the present work to estimate Volterra kernels. The various states of the cracked structure are then estimated using these Volterra kernels. Numerical simulation studies are carried out on a simple beam example to demonstrate the capability of the proposed adaptive Volterra filter in extracting the opening and closing state response from the global response of the cracked structure. © 2018 The Authors. Published by Els v er B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under respon ibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Extraction of Opening and Closing States of Cracked Structure using Adaptive Volterra Filter Model J. Prawin a , A. Rama Mohan Rao b a Scientist, CSIR Struct ral Engi eering Research Centre, Chennai - 600113, INDIA b Chief Scientist, CSIR Structural Engineering Research Centre, Chennai - 600113, INDIA Abstract Fatigue cracks often exist in structures during the service life of th structure a d need t detect at its earliest stage befor it leads to catastrophic failure. Th fatigue breathing crack problem exhibit an instantaneous change in the stiffness of the structure due to change i the state of the cracked domain from open to close and vice versa. Therefore these fatigue cracks exhibit breathing like ph nomena, hence wid ly referred as br athi cracks. The pr sent work attempts to separate the opening and clo ing of the cracked structur from the gl bal response sing adaptive Volterra Filter Model. Adaptive Volterra Filter model is a generalization of the li ear convolution a d the impulse response function to nonlinear structu es in discrete form. The dynami al properties of the nonlinear system in th V lterra series representation or adaptive Volterra Filter Model a e com letely c ara terized by sequence of multi-dimensi al weighting function called Volterra ker els. These Volterra kernels are the backb n of adaptiv Volterra filter approach in nonli ear analysis and system identification nd div rse range of techniques are ep rt d in the literature for Volterra ke nel e timati n. Adaptiv Volterra series based Le st squar is used in the prese t work to estimate Volterra kernels. The vari s states of the cracked structure are then stimated using thes Volterra kernels. Numeric l simulation studies are carried out on a simple beam example to dem nstrate the capability of the proposed adaptive Volterra filter in extracting the opening and closing state response from the global response of the cracked structure. © 2018 The Authors. Published by Elsevier B.V. This is an op n access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Sel ction and peer- eview under responsibil ty o Peer-rev ew under responsibility of the SICE 2018 organizers. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: adaptive Volterra Filter; Volterra Kernel; Convolution; breathing crack; bilinear;nonlinearity; frequency response function Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: adaptive Volte ra Filter; Volterra K rnel; Convolutio ; br athing crack; bi inear;nonli earity; frequency response function

2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

* 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  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.030