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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Evaluation of Pre-strain Effect on Abnormal Fracture Occurrence in Drop-Weight Tear Test for Linepipe Steel with High Charpy Energy Toshihiko Amano a , Taishi Fujishiro b , Yasuhiro Shinohara c , Takehiro Inoue d * a Materials Reliability Research Lab., Research & Development, Nippon Steel & Sumitomo Metal Corporation(NSSMC), Hyogo 660-0891, Japan b Pipe &Tube Research Lab., Research & Development, NSSMC, Hyogo 660-0891, Japan c Kimitsu R & D Lab., NSSMC, Kimitsu Chiba 299-1141, Japan d Plate & Shape Research Lab., Research & Development, NSSMC, Futtsu Chiba 293-8511, Japan Abstract Brittle fracture control is one of the most important subjects in natural gas transmission pipeline in order to maintain structural integrity over several decades. The Drop Weight Tear Test (DWTT) is widely used as the test method to evaluate the resistance against the brittle fracture for linepipe steels. However, an abnormal fracture frequently occurs during the DWTT in recent high toughness line pipe steels. The abnormal fracture is also known as inverse fracture. The abnormal fracture is defined as the cleavage fracture is observed at the hammer side in DWTT specimen although the ductile fracture firstly initiates from the notch tip side. Many studies for abnormal fracture appearance/behavior have been carried out in order to clarify the mechanism of the abnormal fracture occurrence and to ensure the prevention of long brittle fracture propagation for pipelines. In this study, a compressive pre-straining at the impact hammer side in the DWTT specimen was evaluated under quasi static load conditions. The specimen’s surfaces were electrolytically-etched to print circle patterns with 5 mm in diameter in order to measure plastic strain. Charpy impact specimens were taken from the quasi-static loaded and unloaded DWTT specimen to measure the possible influence of pre-straining on toughness. The impact test results show that more than 2 % of the compressive pre-strain gave 7 to 10 % decrease of the Charpy upper-shelf energy. The effect of pre-straining on tensile property was also evaluated. These present experiments indicate that the occurrence of abnormal fracture near the hammer side can be attributed to the compressive pre-straining. Furthermore, the chevron-notched and the pre-cracked DWTTs and the partial gas burst test were conducted in order to compare the brittle-to-ductile transition temperature. Based on these experiments, the effect of notch configuration on the brittle-to-ductile transition temperature and the correlation between DWTTs and pipe test were discussed. In addition, the relationship between the pre-straining and the abnormal fracture appearance was considered. Drop-Weight Tear Test for Linepipe Steel with High Charpy Energy a t i l li ilit ., l t, i t l it t l ti ( ), - , b i ., l t, , - , c i it ., , i it i - , d l t ., Development, NSSMC, Futtsu Chi - , Brittl ct e control i t t i t t j t i t l t i i i li i t i tain t t l i t it l . i t t i i l t t t t t l t t i t i t t ittl t li i t l . , l t tl i t i t i t li i t l . l t i l i t . l t i i t l t i t t i i i lt t til t i tl i iti t the t ti i . t i l t / i i t i t l i t i of the abnormal fracture occurr t t ti l ittl t ti i li . In this study, a compressive pre-straining at the impact hammer side in the DWTT speci was evaluated u i t ti l iti . i were electrolytically-etched to print circle patterns wit i i t i t asure plasti t i . i t i t t i t ti l l i to measure the possible influence of pre-straining on toughness. The impact test result t t t t i t i t t l . t t i i t il t was also evaluated. These present experiments indicate that the occurrence of abnormal f t t i attributed to the compressive pre-straining. t , t t t t ti l burst test were conducted in order to compare the brittle-to-ductile transition temp t . t i t , t t t i ti t ittl t til t iti t t t l ti t i t t i . iti , t l ti i t t t i i t l t i . © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. t . li l i . . Peer-review under responsibilit t e i ti i itt of CF21. Copyright © 2016 The Auth rs. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

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Keywords: DWTT; Linepipe steel; Brittle fracture; Abnormal fracture apperance ; Pre-strain; Partial gas burst test i t l; rittl fr t r ; r l fr t r r ; r - tr i ; rti l r t t t ; i

* Corresponding author. Tel.: +81-6-7670-5875; fax: +81-6-6489-5794. E-mail address: amano.4bf.toshihiko@jp.nssmc.com i t r. l.: - - - ; f : - - - . - il : . f.t i i j . . rr

* 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 ECF21. l i r . . i i ilit t i ti i itt . - t r . li

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.055