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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.2016.06.472 Evaluation of the crack initiation process is usually performed on the basis of the constant load tests. In these tests, the samples are loaded to di ff erent stress levels, typically a fraction of the yield stress, and the time-to-failure is measured. These results demonstrated that: (1) The sample fail faster in time when loaded to high stress values, (2) by increasing neutron dose, the stress required to fail the sample decreases. An estimation of the stress threshold under which no IASCC takes place, gives the value of about 40 % of irradiated yield stress Rao (1999); Bosch et al. (2015). However, large uncertainty observed in the time-to-failure data Bosch et al. (2015) somewhat limits the application of proposed stress threshold. For example, the scatter in the time-to-failure data, obtained for applied stress of 55 % yiel stress (550 MPa), ranges from about 100 h to more than 2000 h. Similar uncertainties are observed in the distribution of cracked bolts fr m nuclear power plant (NPP) field experience. Some bolts are observed to crack while you would not expect them to crack according to relatively low accumulated dose and low temperature. On the ∗ Corresponding author email: mila konst@sckcen.be 2452-3216 c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Irradiation assisted stress corrosion cracking (IASCC) is intergranular cracking e ff ect showing strongly reduced or no ductility, which can ccur in heavily irradiated internal structural components of nuclear reactor cores. The internal components of nuclear re ctor pressure vessels re fabricated primarily with austenitic sta nless steels because of their relatively high strength, ductility, and fracture toughness. Still, the operating co ditions may cau e severe aterial degradation and the component failure, which is extremely important for nuclear power plant safety and lifetime managements. The IASCC is complex phenomenon not yet fully understood because it occurs through an interplay of several material degradation processes: The factors that influence the IASCC susceptibility of materials include neutron irradiation, temperature, water corrosion, stress and material composition Scott (2011); Andersen (2011); Was et al. (2007); Bruemmer et al. (1999). However, despite of accumulated experimental data Rao (1999), both crack initiation and crack propagation mechanisms still need to be elucidated. Evaluation of the crack initi tion process is usually performed on the basis of the constant load tests. In these tests, the samples are loaded to di ff erent stress levels, ty ically a fraction of the yield stress, and the time-to-failure is measured. These results emonstrated that: (1) The sample fail faster in time when loaded to high stress values, (2) by increasing neutron dose, the stress required to fail the sample decreases. An estimation of t e stress threshold under which no IASCC takes place, gives the value of about 40 % of irradiated yield stress Rao (1999); Bosch et al. (2015). However, large uncertainty observed in the time-to-failure data Bosch et al. (2015) somewhat limits the application of proposed stress threshold. For example, the scatter in the time-to-failure data, obtained for applied stress of 55 % yield stress (550 MPa), ranges fr m about 100 h to more than 2000 h. Similar uncertainties are observed in the distribution of cracked bolts from nuclear power plant (NPP) field experience. Some bolts are observed to crack while you would not exp t them t crack according to relatively low accumulated dose and low temperature. On the ∗ Corresponding autho email: milankons @sckc .be 2452-3216 c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. stract A probabilistic fracture echanics odel is applied to irradiation assisted stress corrosion cracking ect, assu ing that the oxidized part of stainless steel sa ple plays an essential role in the crack propag tion and sa ple failure. The Weib ll statistical distribution of ti e-to-failures, esti ated throug the correlation with the statistical distribution of oxide strengths, fully accounts for the experi ental results / scatter obtained in the constant load ti e-to-failure tests. arge failure uncertainties in these type of tests originate fro intrinsic stochastic behavior of the oxide cracking due to subcritical crack propagation process. c ⃝ 2016 he uthors. ublished by lsevier . . eer-review under responsibility of the Scienti c Co ittee of ECF21. ey ords: I S , crack initiation, probabilistic fracture echanics, oxidized stainless steel . I t r cti Irra iati assisted stress c rr si c ac (I ) is i ter ra lar crac i e ect s i str l re c r n ctilit , ic c cc r i ea il irra iate i ter al str ct r l c e ts f clear react r c res. i ter al c ts f clear react r ress re essels are fa ricate ri aril it a ste itic stai less steels ca e f t eir r lati el i stre t , ctilit , a fract re t ss. till, the operating onditi ns may cause severe material degr datio and the component fai ure, which is extremely important f r nucle r power plan safety nd lifetime managements. T e I is c l e e et f ll erst eca se it cc rs t r a i terpla of se eral aterial e ra ati r c sses: e fact r t at i ce t e I s sce ti ilit f aterials i cl e ne tr irra iati , te erat r , ater c rr si , stress a aterial c siti c tt ( ); erse ( ); Was et al. ( ); r e er et al. ( ). e er, es ite f acc late e eri e tal ata a ( ), t crac i itiati a crac r a ati ec a is sti l ee t e el ci ate . al ati f t e crac i itiati r cess is s all erf r e t e asis f t e c st t l a tests. I t es tests, t e sa les are l a e t i ere t stress le els, t icall a fr c i f t iel stress, a t e ti -t -fail re is eas re . ese res lts e strate t at: ( ) e sa le fail faste i ti e e l a e t i stress al es, ( ) i creasi e tr e, t e stress re ire t fail t e sa le ecreases. sti ati f t e stress t res l u er ic o IASCC takes place, gives t e al e f a t f irr iate iel stress a ( ); sc et l. ( ). e er, lar certai t ser e i t e ti e- -fail re ata sc et al. ( ) s e at li its t e a licati f r se stress t res l . r e a le, t e scatter i t e ti e-t -fail re ata, e f r a li stress of ield stress ( a), ra es fr a t t re t a . i ilar certai ties are ser e i t e istri ti f crac e lts fr clear er la t ( ) el e erie ce. e lts ar ser e t crac ile l t e ect t e t crac acc r i t relati el l acc late se a l te erat re. t e ∗ orresponding author e ail: ila konst sckcen.be 2452-3216 c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 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. 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Probabilistic fracture mechanics of irradiation assisted stress corrosion cracking in stainless steels M. J. Konstantinovic´ a a Studiecentrum voor Kernenergie / Centre d’Etude de l’Energie Nucle´aire (SCK · CEN), Boeretang 200, B-2400 Mol, Belgium Abstract A probabilistic fracture mechanics model is applied to irradiation assisted stress corrosion cracking e ff ect, assuming that the oxidized part of stainless steel sample plays an essential role in the crack propagation and sample failure. The Weibull statistical distribution of time-to-failures, estimated through the correlation with the statistical distribution of oxide strengths, fully accounts for the experimental results / scatter obtained in the constant load time-to-failure tests. Large failure uncertainties in these type of tests originate from intrinsic stochastic behavior of the oxide cracking due to subcritical crack propagation process. c ⃝ 2016 The Authors. Published by Elsevier B.V. e r-revie under responsibility of the Scientific Committee of ECF21. Keywords: IASCC, crack initiation, probabilistic fracture mechanics, oxidized stainless steel 1. Intorudcti Irradiation assist stress corrosion cracking (IASCC) is intergranular cracking e ff ect showing strongly reduced or no ductility, w ich can occur in heavily irradiated internal structural components of nuclear reactor cores. The internal components of nuclear reactor pressure vessels are fabricated primarily with austenitic stainless steels because of their relatively high strength, ductility, and fracture toughness. Still, the operating conditions may cause severe material degradation and the component failure, which is extremely important for nuclear power plant safety and lifetime managements. The IASCC is complex phenomenon not yet fully understood because it occurs through an interplay of several material degradation processes: The factors that influence the IASCC susceptibility of materials include neutron irradiation, temperature, water corrosion, stress and material composition Scott (2011); Andersen (2011); Was et al. (2007); Bruemmer et al. (1999). However, despite of accumulated experimental data Rao (1999), both crack initiation and crack propagation mechanisms still need to be elucidated. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Probabilistic fracture mechanics of irradiation assisted stress corrosion cracking in stainless steels M. J. Konstantinovic´ a a Studiecentrum voor Kernenergie / Centre d’Etude de l’Energie Nucle´aire (SCK · CEN), Boeretang 200, B-2400 Mol, Belgium Abstract probabilistic fracture mechanics model is applied to irradiation assisted stress corrosion cracking e ff ect, assuming that the oxidized part of stainless steel sample plays an essential role in the crack p op gation and sample failure. The Weibull statistical distribution of time-to-failures, estimated through the correlation with the statistical distribution of oxide strengths, fully accounts for the experimental results / scatter obtained in the constant load time-to-failure tests. Large failure uncertainties in these type of tests originate from intrinsic stochastic behavior of the oxide cracking due to subcritical crack propagation process. c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: IASCC, crack initiation, probabilistic fracture mechanics, oxidized stainless steel 1. Intorudction st r f r r t r , , - J , t i , It l ni . . t ti i´ a a Studiecentru voor ernenergie / entre d’ tude de l’ nergie ucle´aire (S · ), oeretang 200, -2400 ol, elgiu © 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.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt