PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1297–13 4 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Int grity 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Numerical Simulation of Thermal Ageing Effect on Fracture Behavior for CF8A Cast Stainless Steels under Very Low Cyclic Loading Conditions Gyo Geun Youn a , Hyun Suk Nam a , Yun Jae Kim a , Jin Won Kim b a Department of mechnical engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea b Department of nuclear engineering, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759, South Korea Abstract In this paper, a method to predict the fracture toughness of thermally-aged CF8A under cyclic loading condition is proposed. The FE damage model based on multi-axial fracture strain energy is applied for the prediction. The predicted results are compared with the experimental data of C(T) specimens. The multi-axial fracture strain energy of unaged CF8A can be obtained from tensile and C(T) data under monotonic loading condition. Then, the multi-axial fracture strain energy of aged CF8A can be determined by introducing the concept of thermal ageing constant “ C ”. From the determined multi-axial fracture strain energy of aged CF8A, the fracture toughness of aged CF8A is predicted under monotonic and cyclic loading condition. The predicted results show good agreement with experimental data. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of th ECF22 organiz rs. Keywords: fracture toughness; multi-axial fracture strain energy; low cycle fatigue; C(T) test; themal ageing constant; finite lement method 1. Introduction CF8A cast stainless steel is widely used for primary pressure components in pressurized water (PWR) nuclear reactor components since it resists well for stress corrosion cracking and has good mechanical strength. However, if CF8A is exposed to PWR operating temperatures (about 320 o C) for a long time, it can easily lose its ductility and toughness by the reason of spino al d composition of δ -ferrite [Peckner et l, Chung et al]. This material degradation phenomenon is called thermal ageing. Until now, many researchers have worked on thermal ageing of CF8A such as Shah et al, Braden et al and Chopra et al. However, there are few researches considering cyclic effect of aged CF8A. It is necessary to consider cyclic effect of aged CF8A because it is crucial to perform safety assessment of aged nuclear components under seismic loading condition. ECF22 - Loading and Environmental effects on Structural Integrity Numerical Simulation of Thermal Ageing Effect on Fracture Behavior for CF8A Cast Stainless Steels under Very Low Cyclic Loading Conditions Gyo Geun Youn a , Hyun Suk Nam a , Yun Jae Kim a , Jin Won Kim b a Department of mechnical engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea b t t f nuclear engi eering, Chosun University, Seosuk- , Do -gu, Gwangju 501 59, t Abstract In this paper, a method to predict the fracture toughness of thermally-aged CF8A under cyclic loading condition is proposed. The FE damage mod l based on multi-axial fracture strain energy is applied for the prediction. The pre icted results are compared with the experimental data of C(T) specimens. The multi-axial fract re strain energy of unaged CF8A can be obtained from tensile and C(T) data under monot nic loading condition. Then, the multi-axial f cture strain ener y of aged CF8A can be eter ined by i troducing the concept of thermal ageing constant “ C ”. From the determined multi-axial fracture strain energy of ag d CF8A, the fracture toug ness of aged CF8A is predi ted u der mon tonic and cyclic loading condition. The predicted results show good agreement with experimental data. © 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fracture toughness; mult -axial fracture strain energy; ow cycle fa igu ; C(T) t st; themal ageing constant; finite element m thod 1. Introduction CF8A cast stainless steel is widely used for primary pressure components in pressurized water (PWR) nuclear reactor components since it resists well for stress corrosion cracking and has good mechanical strength. However, if CF8A is exposed to PWR operating temperatures (about 320 o C) for a long time, it can easily lose its ductility and toughness by the reason of spinodal decomposition of δ -ferrite [Peckner et al, Chung et al]. This material degradation phenomenon is called thermal ageing. Until now, many researchers have worked on thermal ageing of CF8A such as Shah et al, Braden et al and Chopra et al. However, there are few researches considering cyclic effect of aged CF8A. It is necessary to consider cyclic effect of aged CF8A because it is crucial to perform safety assessment of aged nuclear components under seismic loading condition. © 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 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 organizers.

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.2018.12.274