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) 168–173 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 Prediction of fracture in sandwich-structured composite joints using case-based reasoning approach Mohammad Reza Khosravani a, ∗ , Sara Nasiri b , Kerstin Weinberg a a Chair of Solid Mechanics, University of Siegen, Paul-Bonatz-Str. 9-11, 57068, Germany b Department of Electrical Engineering & Comput r Science, University of Siegen, Ho¨lderlinstr. 3, 57076 Siegen, Germany Abstract Repair and replacement of damaged composites are costly and time-consuming processes, therefore a prediction of fracture is highly beneficial, and may enhance structure reliability. I n this study, a case-based reasoning (CBR) methodology as a problem solving method of artificial intelligence is utilized to pre dict fracture occurrence in adhes vely bonded andwich joints. CBR is an intelligent technique for solving new problems by finding previo s similar problems based on the experiences and cases which have similar solutions. In this paper, the experimental data of sandwich joints which experienced static and dynamic loadings under various environmental conditions are analyzed and stored on the case base. The case base of the implemented system is also enriched by numerical simulation results. The developed tool is appropriately designed with the optimized cases which are performed to reach high robustness in the fracture prediction. Furthermore, the case-base updates while using the system by learning from the gathered data as requested problems. Therefore, higher performance in future problems can be achieved. The proposed intelligence system has a general reliability to apply for di ff erent types of joints in sandwich-structured composites in order to predict failure load and type of failure. The quality of the obtained results of this research fully demonstrated the usefulness of the proposed intelligent system. c � 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: sandwich-structured composites; fracture prediction; case-based reasoning; failure load. © 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental e ff ects on Structural Integrity Prediction of fracture in sandwich-structured composite joints using case-based reasoning approach Mohammad Reza Khosravani a, ∗ , Sara Nasiri b , Kerstin Weinberg a a Chair of Solid Mechanics, University of Siegen, Paul-Bonatz-Str. 9-11, 57068, Germany b Department of Electrical Engineering & Computer Science, University of Siegen, Ho¨lderlinstr. 3, 57076 Siegen, Germany Abstract Repair and replacement of damaged composites are costly and time-consuming processes, therefore a prediction of fracture is highly beneficial, and may en nce structur reliabil y. I n this study, a case-base r ason ng (CBR) methodology as a problem solving method of artificial intelligence is utilized to pre dict fracture occurrence in adhesively bonded sandwich joints. CBR is an intelligent technique for solving new problems by finding previous similar problems based on the experiences and cases which have similar solutions. In this paper, the experimental data of sandwich joints which experienced static and dynamic loadings under various environmental conditions are analyzed and stored on the case base. The case base of the implemented system is also enriched by numerical simulation results. The developed tool is appropriately designed with the optimized cases which are performed to reach high robustness in the fracture prediction. Furthermore, the case-base updates while using the system by learning from the gathered data as requested problems. Therefore, higher performance in future problems can be achieved. The proposed intelligence system has a general reliability to apply for di ff erent types of joints in sandwich-structured composites in order to predict failure load and type of failure. The quality of the obtained results of this research fully demonstrated the usefulness of the proposed intelligent system. c � 018 The Authors. Published by Elsevier B.V. r r vi w unde responsibility of the ECF22 organizers. Keywords: sandwich-structured composites; fracture prediction; case-based reasoning; failure load.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

1. Introduction 1. Introduction

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Remarkable and unique properties of various composite materials lead to a broad range of their application in today’s life. This increasing trends in numerous utilization of composites, needs higher powerful techniques for as sessment of the composite e ffi ciency. Since replacement of the composites is a time consuming and costly issue, fractures and failures can be avoided by prediction of the mechanical behavior of composites. Over the years, various techniques have been employed for performance analysis and predict di ff erent fractures in composite structures [1, 2, 3, 4]. For instance, in [1] linear elastic fracture mechanics is used to analyze experimental Remarkable and unique properties of various composite materials lead to a broad range of their application in today’s life. This increasing trends in numerous utilization of composites, needs higher powerful techniques for as sessment of the composite e ffi ciency. Since replacement of the composites is a time consuming and costly issue, fractures and failures can be avoided by prediction of the mechanical behavior of composites. Over the years, various techniques have been employed for performance analysis and predict di ff erent fractures in composite structures [1, 2, 3, 4]. For instance, in [1] linear elastic fracture mechanics is used to analyze experimental

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. ∗ Corresponding author. Tel.: + 49(0271)740-4642 ; fax: + 49(0271)740-2241. E-mail address: mohammadreza.khosravani@uni-siegen.de 2210-7843 c � 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ∗ Corresponding author. Tel.: + 49(0271)740-4642 ; fax: + 49(0271)740-2241. E-mail address: mohammadreza.khosravani@uni-siegen.de 2210-7843 c � 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.028