PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Available o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 713–72 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Influence of material non-linearity on load carrying mechanism and strain path in stiffened panel Mihkel Kõrgesaar a *, Jani Romanoff a , Heikki Remes a a Aalto University, Department of Mechanical Engineering, Puumiehenkuja 5a, 00076 Aalto, Espoo, Finland Abstract This paper investigates the influence of material non-linearity on load carrying mechanism and strain path in stiffened panel. First, clamped stiffened panel with dimensions of 1.2 x 1.2 m was penetrated with rigid indenter until fracture took place. Second, panel material was characterized with standard tensile tests using flat test coupons extracted from the face sheet of the panel. Failure strain for different element lengths was calibrated using iterative state-of-the-art procedure. Numerical finite element simulations were performed using failure strain calibrated with tensile tests. Comparison of numerical and experimental force-displacement curves of panel clearly shows that this widely used approach is not sufficient for reliable element size independent numerical simulations. The reason is that failure strain scaling depends on the element size as well as stress state. The stress state in the structural component however, can considerably vary from that o served in tensile test. © 2017 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scie tific Committee of ICSI 2017. Keywords: Type your keywords here, s parated by semic lons ; A reliable consideration of material non-linearity and failure strain in crashworthiness analysis of large complex structures such as ship is a challenge with an increasing importance in the last decades. Ship collisions, groundings and penetrat on of objects through th shell plating of t e ship can lead to loss of ship buoyancy and consequent 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Influence of material non-linearity on load carrying mechanism and strain path in stiffened panel Mihkel Kõrgesaar a *, Jani Romanoff a , Heikki Remes a a Aalto University, Department of Mechanical Engineering, Puumiehenkuja 5a, 00076 Aalto, Espoo, Finland Abstract This paper investigate th influence of material non-linearity on load c rryi g mechanism an strai path in stiffened panel. First clamped stiff ned p nel wit dim nsions of 1.2 x 1.2 m was penetrated with rigid inde ter until fracture took place. Second, panel material was characterized with sta dard tensile tests using flat test coupons extracted from the face sheet of the panel. Failur strain for different element l ngths was calibrated using iterative state-of-th -art procedure. Numerical finite el ment simulations were p rformed using failure str in calibrated with tensile te ts. Comp rison f n merical and experim ntal force-displacement curves of panel clearly show that t is widely used approach is not sufficient for reliable element ize independent numerical simulations. The reason is that failure strai scaling depends on the element siz as w ll as stress state. The stress state in the structural component however, can considerably vary from t at observed in tensile test. © 2017 The Autho s. Publ shed by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of ICSI 2017. Keywords: Type your keywords here, separated by emicolons ; 1. Introduction A reliable consideration of material non-linearity and failure strain in crashworthiness analysis of large complex structures such as ship is a challenge with an increasing importance in the last decades. Ship collisio s, groundings and penetration of objects through the shell plating of the ship can lead to loss of ship buoyancy and consequent © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 © 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. 1. Introduction

* Corresponding author. Tel.: +37253439557 E-mail address: Mihkel.korgesaar@aalto.fi * Correspon ing author. Tel.: +37253439557 E-mail address: Mihkel.korgesaar@aalto.fi

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.050 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.