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) 13 5–1311 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. ECF22 - Loading and Environmental effects on Structural Integrity Numerical analysis for the thermal ageing effect on fracture behaviors of CF8A pipes and piping systems under monotonic and very low cycle fatigue loading conditions Gyo Geun Youn a , Hyun Suk Nam a , Yun Jae Kim a a Department of mechnical engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea In this research, the effect of thermal ageing for CF8A is studied under displacement-controlled low cycle fatigue. Virtual tests of pipe and pipe system are considered and they have the same shape and loading conditions as the pipe and pipe systems tested in Battelle. Only material was changed from A106 Gr. B to CF8A. The pipe tests are four-point bending tests with three different load ratio ( R = -1, 0, 1) having through-wall crack. The pipe system test also has through wall crack with seismic loading condition (PGA=1g). To simulate the cyclic loading and thermal ageing effect, multi-axial fracture strain energy based FE damage model and thermal ageing constant “ C ” was applied. From the simulation, it can be known from the virtual pipe test that crack growth rates of unaged and aged CF8A become similar when loading type is changed from monotonic to cyclic. Also, it is can be known from the virtual pipe system test that the crack rowths of u aged and aged CF8A are almost same when the size of through-wall crack is 43.2 o . However, the crack growth of unaged CF8A is almost 25% smaller that aged CF8A when the size of through-wall crack is 90 o . © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Type your keywords here, separated by semicolons ; © 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 analysis for the thermal ageing effect on fracture behaviors of CF8A pipes and piping systems under monotonic and very low cycle fatigue loading conditions Gyo Geun Youn a , Hyun Suk Nam a , Yun Jae Kim a a Department of mechnical engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea Abstract In this research, the effect of thermal ageing for CF8A is studied under displacement-controlled low cycle fatigue. Virtual tests of pipe and pipe system are considered and they have the same shape and loading conditions as the pipe and pipe systems tested in Battelle. Only m terial was chang d from A106 Gr. B to CF8A. he pipe tests are four-point b nding tests with three diff rent lo d ratio ( R = -1, 0, 1) having through-wall crack. The pipe system test also has through wall crack with seismic loading condition (PGA=1g). To simulate the cyclic loading and thermal ageing ffect, multi-axial fracture strain energy based FE amage model and thermal ageing constant “ C ” was applied. From the simulation, it can be known from the virtual pipe test that crack growth rates of unaged a d aged CF8A become similar when loading type is ch ged from monotonic to cyclic. Also, it is can be kno n from the virtual pipe system test that the crack growths of unaged and aged CF8A are alm st same when the size of through-wall crack is 43.2 o . How ver, the crack growth of unaged CF8A is almost 25% smaller that aged CF8A t e si f t ro - ll r ck is 90 o . © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Type your keywords here, separated by semicolons ; Becaus of its resistance for stress corrosion cracking and good mechanical strength, CF8A cast stainless steel is widely used for primary pressure components in pressurized water (PWR) nuclear reactor components. However, CF8A cast stainless steel is easily exposed to thermal ageing at PWR operating temperatures (320 o C). Its ductility and toughness decrease due to the spinodal decomposition of δ -ferrite [Peckner et al, Chung et al]. In the previous study, Youn et al proposed a FE analysis method to predict the fracture toughness of aged CF8A C(T) under cyclic loading condition. Multi-axial fracture strain energy damage model was applied to predict the fracture toughness. In this paper, this method is expanded to pipe and pipe system to predict the crack growth behavior © 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. Because of its resistance for stress corrosion cracking and good mechanical strength, CF8A cast stainless steel is widely used for primary pressure components in pressurized water (PWR) nuclear reactor components. However, CF8A cast stainless steel is easily exposed to thermal ageing at PWR operating temperatures (320 o C). Its ductility and toughness decrease due to the spinodal decomposition of δ -ferrite [Peckner et al, Chung et al]. In the previous study, Youn et al proposed a FE analysis method to predict the fracture toughness of aged CF8A C(T) under cyclic loading condition. Multi-axial fracture strain energy damage model was applied to predict the fracture toughness. In this paper, this method is expanded to pipe and pipe system to predict the crack growth behavior Abstract 1. Introduction 1. Introduction

* 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.2018.12.275