PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 2239–2244 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 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 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDir ct Structural Integrity Procedia 00 (2018) 000–000

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www.elsevier.com/locate/procedia ECF22 - Loading and Environmental effects on Structural Integrity Simulating toughness properties under varying temperatures with micromechanical and phenomenological damag models David Lenz a , * , Markus Köneman a , Victoria Brinne a , Julius Langenberg a , Sebastia Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract The sustainable and efficient use of high-strength micro-alloyed steels is of particular interest in today’s industry. Using modern ste ls with high strength and excellent toughness enables thinne constructions, for example in infrastructure applications, for pressure vess ls or pipelines. Sufficie t tough ess i of special importance to avoid catastrophic brittle fail re. Yet, the simplified, conventional design rules prevent a full exploitation of the properties of m dern high strength steels. Modern simulation models ar able to represent the actual failure characteristics high strength steels and thereby h l to fully xploit the potential of th se materials. To include toughness prop rties, it is essential that the models are ble to describe the transition behavior of these ste ls. The m terials’ behavior in the transition region i characterized by a competition of ductile and cleavage failure mechanisms. To simulate the correspondi g beh vior, it is nece sary to adapt damage mechanics models for considering both effect . While numerous studies on the simulation of eith r ductile or cleavage failure xist, only a li ited selecti is available on investigations in th transition range. Therefore, the presented study investigates two representatives of the most popular groups of ductile failure mod ls. The Gurson-Tvergaard-Needleman model (GTN) is investigated as a micromechanical model while the Modified-Bai Wierzbicki model (MBW) is selected as a phen menological model. Both are co bined with the Orowan cleavage fracture model. Investigations are performed on a thermomechanical rolled S355, for which the cleavag fr cture stress and the parameters for the ductile failure mod ls were experiment lly determined. The study c mpares simulations of Charpy impact toughness tests to experimental results to det rmine which model class delivers results that are more accurate. The focus of the investigation i hereby set on the simulation of the low r shelf nd the lower tran ition area. In addition, the efficiency of the simulations p rformed is also evaluated. ECF22 - Loading and Environmental effects on Structural Integrity Simulating toughness properties under varying temperatures with micromechanical and phenomenological damag models David Lenz a , * , Markus Könemann a , Victoria Brinnel a , Julius Langenb rg a , Sebastian Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germ ny Abstract The sustainable and efficient use of high-strength micro-alloyed steels is of particular interest in today’s industry. Using modern ste l with high strength a d excellent toughness enables thinner constructions, for example in infrastruct re applications, for pr s ure vessels or pipelines. Sufficie t toughness is of special import ce to avoid catastrophic brittle fail re. Yet, the simplified, conventional d sign rules prevent full exploitation of the proper ies of m dern high str ngth steels. Modern simulation odels are able to represent the actual failure characteristics high strength steels and thereby h l to fully exploit the potent al of these materials. To include toughness prop r ies, it is essential that the models are ble to describe the transition behavior of these s e ls. The m teri s’ behavi r in the transition region is characterized by a c mpetition of ductile and cl avage failure echanis s. To simulate the correspond g beh vior, it is necessary to adapt damage m cha ics mod ls f r onsidering both ffects. Whil numerous studies on the simulation f either ductile or cleavage failure xist, only a li ited el cti is available on investigations in th transition range. Therefore, the presented study inv st gates two r presentatives of the m s popul r groups of ductile f ilure models. The Gu son-Tvergaard-Ne dlema model (GTN) s investigated as a micromec anical model while the Mod fied-Bai Wierzbicki model (MBW) is selected as a phen menological mod l. Both are co bined with the Orowan cleavage fracture model. I vestigations are performed on a ermomechanical rolled S355, for which the cleavage frac ure stress and the parameters for th ductile fa lure models were experimentally determined. The study comp res simul tions of Charpy impact oughn ss tests to experimental results to determine which mod l class delivers re ults that are more accurate. The focus of the in estigation is hereby set on the simulation f the l wer shelf and the lower tran ition area. In addition, the efficiency of the simulations p rformed is also evaluated. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern society, science and industry. New steel grades have been developed to reduce steel consumption. In addition to very good strength, these also have excellent toughness. Areas of application include the construction industry, pipeline construction and the automotive industry. Due to the improved properties, the wall thickness of components can be significantly reduced and thus also the required quantity of steel and additives, e.g. welding consumables. A reduction in wall 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern society, science and industry. New steel grades have been developed to reduce steel consumption. In addition to very good strength, these als have excellent toughness. Areas of application include the construction industry, pipeline construction and the automotive industry. Due to the improved properties, the wall thickness of components can be significantly reduced and thus also the required quantity of steel and additives, e.g. welding consumables. A reduction in wall 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern society, science and industry. New steel grades have been developed to reduce steel consumption. In addition to very good strength, these also have excellent toughness. Areas of application include the co structi n industry, pipelin construction and the automotive industry. Due to the improved properties, the wall thickness of components can be significantly reduced and thus also the required quantity of steel and additives, e.g. welding consumables. A reduction in wall 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern society, science and industry. New steel grades have been developed to reduce steel consumption. In addition to very good strength, these also have excellent toughness. Ar as of application include the co truc industry, pipeline construction and the automotive industry. Due to the improved properties, the wall thickness of components can be significantly reduced and thus also the required quantity of steel and additives, e.g. welding consumable . A reduction in wall 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern society, science and industry. New steel grades have been dev loped to reduce steel con umption. In addition to very go d strength, these also have xcelle t toughness. Areas of application include the construc n industry, pipelin construction and t automotive industry. Due to the improved properties, the wall thickness of compone ts can be significantly reduced and thus also the required quantity of steel and additives, e.g. welding consumable . A reduction n wall * Corresponding author: E-mail address: david.lenz@iehk.rwth-aachen.de 1. Introduction Today, the demand for steel is greater than ever. Increased demand for the material may lead to a bottleneck in subsequent deliveries in the future. This limited availability of resources is a major issue in modern socie y, science and industry. N w steel grades have be n dev loped to reduce steel con umption. In addition to very go d strength, the e also have xc ll t toughness. Areas of application include the c struc industry, pip lin construction and t automoti industry. Du to the impr ved roperti s, the wall thickness of compone ts can be significan ly reduced and thus also the required quantity of steel and additives, e.g. welding consumable . A reduction n wall * Corresponding author: E-mail address: david.lenz@iehk.rwth-aachen.de 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 Simulating toughness properties under varying temperatures with micromechanical and phenomenological damage models David Lenz a , * , Markus Könemann a , Victoria Brinnel a , Julius Langenberg a , Sebastian Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract The sustainable and efficient use of high-strength micro-alloyed steels is of particular interest in today’s industry. Using modern steels with high strength and excellent toughness enables thinner constructions, for example in infrastructure applications, for pressure vessels or pipelines. Sufficient toughness is of special importance to avoid catastrophic brittle failure. Yet, the simplified, conventional design rules prevent a full exploitation of the properties of modern high strength steels. Modern simulation models are able to represent the actual failure characteristics of high strength steels and thereby help to fully exploit the potential of these materials. To include toughness properties, it is essential that the models are able to describe the transition behavior of these steels. The materials’ behavior in the transition region is characterized by a competition of ductile and cleavage failure mechanisms. To simulate e corr sponding behavior, it is necessary to adapt damage m hanics models for considering both effects. While num rous s udies on the imulation of either ductile or cleavage failure exist, only a limi ed sel cti n s available on investigations in the tr nsition range. Therefore, the present d study investigates two representatives of the most popular gr ups of ductile failure models. The Gurs n-Tvergaard-Needleman mo el (GTN) i investigated s a m crome h nical mo l while the Modif ed-Ba - Wierzbicki model (MBW) is selected as a phenomenological model. Both are combined with the Orowan cleavage fractur model. I v stigati ns are performed on a thermomechanical rolled S355, for which the cl avage fracture stress and the parameters for the ductile failure models were experimentally determined. The study compares simulations of Charpy impact toug ness tests to experimental results to determine which model class delivers results that are more accurate. The focus of the investigation is hereby set on the simulation of the lower shelf and the lower transition area. In addition, the efficiency of the simulations performed is also evaluated. ECF22 - Loading and Environmental effects on Structural Integrity Si ulating toughness properties under varying temperatures with micromechanical and phenomenological da age odels David Lenz a , * , Markus Könemann a , Victoria Brinnel a , Julius Langenberg a , Sebastian Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract The sustainable and efficient use of high-stre gth micro-alloyed steels is of particular interest in today’s industry. Using modern steels with high strength and excellent toughness enables thinne constructions, for example in infrastructure applications, for pressure vessels or pipelines. Sufficient toughness is of special importance to avoid catastrophic brittle failure. Yet, the simplified, conventional design rules prevent a full exploitation of the properties of modern high strength steels. Modern simulation models are able to represent the actual failure characteristics of high strength steels and thereby help to fully exploit the potential of these materials. To include toughness properties, it is essential that the models are able to describe the transition behavior of these steels. The materials’ behavior in the transition region is characterized by a competition of ductile and cleavage failure mechanisms. To simulate the corresponding behavior, it is necessary to adapt damage mechanics models for considering both effects. While numerous studies on the simulation of either ductile or cleavage failure exist, only a limited selection is available on investigations in the transition range. Therefore, the presented study investigates two representatives of the most popular groups of ductile failure models. The Gurson-Tvergaard-Needleman model (GTN) is investigated as a micromechanical model while the Modified-Bai Wierzbicki model (MBW) is selected as a phenomenological model. Both are combined with the Orowan cleavage fracture model. Investigations are performed on a thermomechanical rolled S355, for which the cleavage fracture stress and the parameters for the ductile failure models were experimentally determined. The study compares simulations of Charpy impact toughness tests to experimental results to determine which model class delivers results that are more accurate. The focus of the investigation is hereby set on the simulation of the lower shelf and the lower transition area. In addition, the efficiency of the simulations performed is also evaluated. ECF22 - Loading and Environmental effects on Structural Integrity Simulating toughness properties under varying temperatures with micromechanical and phenomenological damage models David Lenz a , * , Markus Könemann a , Victoria Brinnel a , Julius Langenberg a , Sebastian Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract The sustainable and efficient use of high-strength micro-alloyed steels is of particular interest in today’s industry. Using modern steels with high str ngth and excellent toughness enables thinner constructions, for example in infrastructure applications, for pressure vessels or pipelines. Sufficient toughness is of special importance to avoid catastrophic brittle failure. Yet, the simplified, conventional design rules prevent a full exploitation of the properties of modern high strength steels. Modern simulation models are able to represent the actual failure characteristics of high strength steels and thereby help to fully exploit the potential of these materials. To include toughness properties, it is essential that the models are able to describe the transition behavior of these steels. The materials’ behavior in the transition region is characterized by a competition of ductile and cleavage failure mechanisms. To simulate the corresponding behavior, it is necessary to adapt damage mechanics models for considering both effects. While numerous studies on the simulation of either ductile or cleavage failure exist, only a limited selection is available on investigations in the transition range. Therefore, the presented study investigates two representatives of the most popular groups of ductile failure models. The Gurson-Tvergaard-Needleman model (GTN) is investigated as a micromechanical model while the Modified-Bai Wierzbicki model (MBW) is selected as a phenomenological model. Both are co bined with the Orowan cleavage fracture model. Investigations are performed on a thermomechanical rolled S355, for which the cleavage fracture stress and the parameters for the ductile failure models were experimentally determined. The study compares simulations of Charpy impact toughness tests to experimental results to determine which model class delivers results that are more accurate. The focus of the investigation s hereby set on the simulation of the lower shelf and the lower transition area. In addition, the efficiency f he simulations performed is also evaluated. ECF22 - Loading and Environmental effects on Structural Integrity Si ulating toughness properties under varying temperatures with micromechanical and phenomenological damag mod ls David Lenz a , * , Markus Könemann a , Victoria Brinnel a , Julius Langenberg a , Sebastian Münstermann a a Steel Institute (IEHK) RWTH-Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract The sustainable and efficient use of high-strength micro-alloyed steels is of particular interest in today’s industry. Using modern steels with high strength and excellent toughness enables thinner constructions, for example in infrastructure applications, for pressure vessels or pipelines. Sufficient toughness is of special importance to avoid catastrophic brittle failure. Yet, the simplified, conventional design rules prevent full exploitation of the roperties of modern high strength steels. Modern simulation models are able to represent the actual failure characteristics f high strength steels and thereby help to fully exploit the potential of these materials. To include toughness properties, it is essential that the models are able to describe the transition behavior of these steels. The materials’ behavior in the transition region is characterized by a competition of ductile and cleavage failure mechanisms. To simulate the corresponding behavior, it is necessary to adapt damage mechanics models for considering both effects. While numerous studies on the simulation of either ductile or cleavage failure exist, only a limited selection is available on investigations in the transition range. Therefore, the presented study investigates two representatives of the most popular groups of ductile failure models. The Gurson-Tvergaard-Needleman model (GTN) is investigated as a micromechanical model while the Modified-Bai Wierzbicki model (MBW) is selected as a phenomenological model. Both are co bined with the Orowan cleavage fracture model. Investigations are performed on a thermomechanical rolled S355, for which the cleavage fracture stress and the parameters for the ductile failure models were experimentally determined. The study compares simulations of Charpy impact toughness tests to experimental results to determine which model class delivers results that are more accurate. The focus of the investigation is hereby set on the simulation of the lower shelf and the lower transition area. In addition, the efficiency of the simulations performed is also evaluated. © 2018 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. © 2018 The A thors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. Keywords: Toughness characterization; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibi ty of the CF22 organizers. © 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. Keywords: To ghness character zation; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Tou ness characterization; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test Keywords: Toughness characterization; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test Keywords: Toughness characterization; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test Keywords: Toughness characterization; ductile fracture; cleavage fracture; phenomenological damage model; micromechanical damage model; transition range; charpy v-notch test * 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. 10.1016/j.prostr.2018.12.134 * Corresponding author: E-mail address: david.lenz@iehk.rwth-aachen.de * Corresponding author: E mail address: david.le z@iehk.rw -aachen.de * Corresponding author: E-mail address: david.lenz@iehk.rwth-aachen.de * Co responding author: E-mail address: david.lenz@iehk.rwth-aachen.de