PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 799–8 5 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

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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 effects on Structural Integrity Effect of crack opening velocity on fracture behavior of hyperelastic semi-structural adhesive joints subjected to mode I loading Christopher Schmandt, Stephan Marzi Technische Hochschule Mittelhessen, Giessen, Wiesenstraße 14, 35390, Germany Abstract Rubber-like adhesive joints provide substantial advantages compared to epoxy-based adhesive joints regarding their damping properties, fatigue resistance and energy consumption under impact. Polyurethane-based adhesives with high modulus are even used in structural applications like car body production. The work to be presented describes the dependency of mechanical mode I failure of a hyperelastic semi-structural adhesive on loading rate. Double cantilever beam (DCB) specimens were manufactured with an adhesive layer thickness of 3 mm. In a first test setup, driving velocity of the testing machine was controlled on optically measured crack opening velocity, varying over several orders of magnitude within external setpoint generation. The tests were driven until crack propagation took place and the position of optical measurement was not valid anymore. The J-integral according to Rice (1968) was calculated directly from measured force acting on the DCB specimen and rotation angle of force introduction points, using an analytical appr ach of Anthony and Paris (1988). In a second test setup, drivi g velocity of the testing machine was varied over several orders and tests were driven until complete failure of the adhesive joint. Pictures recorded from specimen’s edge were used to analyze the rate dependency of crack propagation and fracture behavior.The observed correlation between J and current crack opening velocity showed that fracture energy was significantly and cohesive strength slightly increasing under higher crack opening velocities, while cohesive stiffness remained constant. In a certain range of loading rates, discontinuous crack growth with stick-slip crack propagation was observed. Below and above this range, crack propagation rate was tending to be more stable. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Effect of crack opening velocity on fracture behavior of hyperelastic semi- tructural adhesive joints subjected to mode I loading Christopher Schmandt, Stephan Marzi Technische Hochschule Mittelhessen, Giessen, Wiesenstraße 14, 35390, Germany Abstract Rubber-like adhesive joints provide substantial advantages compared to epoxy-based adhesive joints regarding their damping properties, fatigu resistance and energy consumption under impact. Polyurethane-based adhesives with high modulus are even used in structural applications like car body production. The work to be presented describes the dependency of mechanical mod I failure of a hyperelastic se i-structur l adhesive on l adi g ra e. D uble ca tilever b am (DCB) pecimens wer manufactured with an adhesive layer thicknes of 3 mm. In a first test setup, driving velocity of th testing machine was controlled on opti ally measured crack opening velocity, varying over several ord rs of magnitude within external setpoint generati . The tests were driv n ntil r propagation took place and the position of optical measurement was not valid a ymor . The J-integral according to Rice (1968) was c lculated directly from measured f rce acting on the DCB specimen an rotati n angl of force introduction points, using an nalytical approach of Anthony and Paris (1988). In a second test s tup, driving velocity of the testing machine was varied over several orders and tests were driven until complete failure of the adhe ive joint. Pictures recorded from specime ’s edge were us d to analyze the rate d pendency of crack propagation and fracture behavior.The observed correlation between J and current crack op ning velocity showe that fracture energy was significantly and cohesive strength slightly increasing under higher crack opening velocities, while cohesive stiffness remained con tant. In a certain range of loading rates, discontinuous crack growth with stick-slip crack propagation was observed. Below a d above this range, crack propagation rate wa tending to be more stable. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 1. Introduction Especially in car manufacturing, structural adhesive bonding has become a widely used technology to connect dissimilar materials like steel, aluminum or composites. In this regard, joining within structural applications is generally dominated by epoxy adhesives. Therefore, literature contains many contributions to mechanical fracture behavior of epoxy-based adhesives but just a few to fracture behavior of hyperelastic polyurethane adhesives. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Adhesive; Rubber; Mode I fracture; Viscoelasticity Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 1. Intro uction Especially in car manufacturing, structural adhesive bonding has become a widely used technology to connect dissimilar materials like steel, aluminum or composites. In this regard, joining within structural applications is generally dominated by epoxy adhesives. Therefore, literature contains many contributions to mechanical fracture behavior of epoxy-based adhesives but just a few to fracture behavior of hyperelastic polyurethane adhesives. Keywords: Adhesive; Rubber; Mode I fracture; Viscoelasticity

* 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. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 o ganizers.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.154