PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1879–1887 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity 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 Validity limits of the one-parameter elastic-plastic fracture mechanics ( J -integral) considering SE(B), C(T) and clamped SE(T) specimens Gustavo Henrique Bolognesi Donato a * , Felipe Cavalheiro Moreira a a Centro Universitário FEI, Humberto de A. Castelo Branco Av., 3972, São Bernardo do Campo, 09850-901, Brazil Abstract The increasing severity of current structural applications (stresses, strains, displacements and aggressive environments), combined to the use of high toughness materials and low constraint geometries, strongly affects the validity of fracture mechanics methods to predict the mechanical behavior and final fracture of such structures using data obtained from laboratory tests, motivating further research in the field. However, the most important aspect of the one-parameter fracture mechanics framework is to ensure that the stress-fields in a reduced laboratory specimen are comparable to those found in real structures to whose design the properties taken from the specimen will be employed. This is the similitude concept, in which a single-parameter can describe the stress-fields ahead of a specimen’s or structure’s crack tip. To establish objective criteria for assessing similitude, this work compared the stress-fields obtained from high-constraint reference models (MBL) with those obtained from laboratory scale fracture mechanics specimens. The extensive analysis matrix, considering computational simulations under plane-strain, complemented by 3-D analyses, allowed the determination of the deformation limits M for C(T), SE(B) and clamped SE(T) geometries considering a wide range of geometrical features and material properties characteristic of structural steels applicable to pressure vessels and pipelines. The results confirmed the low constraint response for short-cracked SE(B) and SE(T) specimens and clarified the effects of crack depth and thickness on M values. In addition, some unexpected behaviors were evidenced and explained, as the case in which (for some particular crack depths and loading modes) thin specimens seem to be more constrained than thick ones. Thus, this work provides insights and quantitative results that enable the development of an objective basis to guarantee similitude in structural integrity assessments based on elastic-plastic fracture mechanics supported by the J -integral either with its critical values ( Jc ) or J-R curves. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Validity limits of the one-parameter elastic-plastic fracture mechanics ( J -integral) considering SE(B), C(T) and clamped SE(T) specimens Gustavo Henrique Bolognesi Donato a * , Felipe Cavalheiro Moreira a a Centro Universitário FEI, Humberto de A. Castelo Branco Av., 3972, São Bernardo do Campo, 09850-901, Brazil Abstract The increasing severity of current structural applications (stresses, strains, displacements and aggressive environments), combined to the us of high toughness materials and low constraint geometries, strongly affects the validity of fracture mechanics methods to predict the mechanical behavior and final fracture of such structures using dat obtained from lab ratory tests, motivating further research in the field. However, the most important aspect of the one-parameter fracture mechanics f mework is t ensure that the str ss-fields in a re uced labo a ory speci en are comparable to those found in re l st uctures to whose design the prope ties taken from the specimen will be employed. This is the similitude concept, in which a sing e-param ter can describe the stress-field ahead of a specim n’s or structur ’s crack tip. To establ sh objective riter a for asses i similitude, this work compared the stres -fields btain d from high-const aint reference models (MBL) with those obtained from labora ory scale fracture mechanics specim ns. The extensive analysis matrix, considering computational simulations und r plane-strain, complemented by 3-D analyses, allowed the det rmination of the deformation limits M for C(T), SE(B) and clam ed SE(T) ge etries considering a wid r nge of geometrical features and material properties characteristic of structural steels applicable to pressure vess ls and pip lines. The r sults confirmed the low constraint esponse for short-cra ked SE(B) and SE(T) s ecimens and clarified the effects of crack depth and thickness on M values. In addition, some unexpected behaviors were evidenced and explained, as the case in which (for some particular crack depths and loading modes) thin specimens seem to be more constraine than thick ones. Thus, this work provides insights and quantitative results that enable the development of an objective basis to guarantee similitude in structural integrity assessments based on elastic-plastic fracture mechanics supported by the J -integral either with its critical values ( Jc ) or J-R curves. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Elastic-plastic fracture mechanics; J-integral; Deformation limit (M); C(T) specimens; SE(B) specimens; SE(T) specimens. © 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. Keywords: Elastic-plastic fracture mechanics; J-integral; Deformation limit (M); C(T) specimens; SE(B) specimens; SE(T) specimens.

* Corresponding author. Tel.: +55-11-43532900. E-mail address: gdonato@fei.edu.br * Corresponding author. Tel.: +55-11-43532900. E-mail ad ress: gdonato@fei.edu.br

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review und r responsibil ty 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.2018.12.325