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) 1 4–1 9 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 il l li t . i i t. tr t r l I t rit r i ( )

www.elsevier.com/locate/procedia . l i r. /l t / r i

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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Computer simulation of cleavage fracture surface morphologies in steel plates Taiko Aikawa a , Shuji Aihara a * , Tomoya Kawabata a , Fuminori Yanagimoto a , Kazuki Shiban ma a a The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan Abstract A computer simulation model has been developed to reproduce b ittle fracture surface morphologies. Local stress intensity factor along a propagating crack front is lculated considering the fracture surface irregularity and crack front non-straightness. Shear stress exerted at fracture surface steps and crack closure stress by uncracked ligament are also taken into consideration in calculating the local stress intensity factor. The local stress intensity factor is compared with assumed critical value to judge if a crack propagate or arrests at each crack front location. The model was found to reproduce chevron markings and shear-lips, both of which are typical of cleavage fracture in steels. The present model was applied to wide-plate crack arrest test with temperature-gradient. Changes of fracture surface morphologies and arrest crack length were well reproduced by the present model. © 2018 The Authors. Published by Elsevier B.V. Pee -r view under responsi ility of the ECF22 organizers. Keywords: Brittl fracture; fracture surface orphology; r ck propagation and arrest 1. Introduction Prevention of cleavage fracture is one of the most crucial subjects in maintaining reliability of steel structures. Control and arrest of a propagating cleavage crack is important in realizing double integrity of the structures. Although arrest of a cleavage crack can be realized by so-called high-arrest steels, mechanism of cleavage fracture propagation and arrest has not been fully understood, microscopically as well as macroscopically. Specifically, relationship between cleavage fracture surface morphologies and crack arrest t ughness is far from full understanding. a i it f , - - , , , , - , Abstract t i l ti l l t ittl t l i . l t i t it t l ti t i l l t i i t t i l it rack front non- traightness. Shear t t t t t l t li t l t i t i ti i l l ti t l l t i t it t . l l t i t it t i it iti l l t j i t t t t l ti . l t e chevron markings and sh li , t i t i l l t i t l . t l li t i l t t t t it t t i t. cture surface morphologies and arrest crack length were well reproduced by the present model. © 2018 The Authors. Published by l i . . e i i ilit t i . : rittl fr t r ; fr t r rf r l ; cr r ti rr t . i Prevention of cleavage fracture is o the most cru i l ubjects in i t i i li ilit t l t t . t l t ti l i i t t i li i l i t it t t t . lt t l li ll i t t l , i l t ti t t ll t , i i ll ll i ll . i i ll , l ti i t l t l i t t i ll t i . © 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.

* Corresponding author. Tel.: +81-3-5841-6505; E-mail address: aihara@fract.t.u-tokyo.ac.jp i t r. l.: - - - ; - il : i r fr t.t. -t . .j rr

* 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. t r . li l i r . . i i ilit t i . -

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.2018.12.018