TY  - CONF
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
AU  - Sedmak, Simon
AU  - Aranđelović, Mihajlo
PY  - 2023
UR  - https://www.sciencedirect.com/journal/procedia-structural-integrity/vol/47/suppl/C
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7100
AB  - The large scatter of the experimental fracture toughness data, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, imposed the need to include statistical methods for data processing. Due to the inherent stochasticity, the application of fracture mechanics concepts in the characterization of the DTB transition phenomenon has remained a challenging task over the past 50 years. Various models were developed based on statistical approach to data processing in order to capture the salient features of the phenomenon, but all of them have certain limitations because of the intrinsic complexity of the problem. However, all these models provided a solid basis for the continued development of new approaches in the characterization of DTB. Such two novel models are compared herein. They include size effects and utilize scaling of geometrically similar C(T) specimens, with the aim of obtaining predictions of the fracture toughness. Both proposed models have the weakest link statistics in common. In the present study, the EURO fracture toughness data set for 22NiMoCr37 reactor steel is used and the experimental data obtained at temperature of -60 °C is selected to demonstrate the accuracy of the estimates. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc [MPa√m]. The obtained predictions are in good agreement with the experimental results, taking into account the inherent scatter of the experimental data. The estimate of KJc cumulative distribution function obtained by extrapolation using the novel two-step-scaling method is sensitive to the statistical size of the input data sets.
PB  - Elsevier B.V.
C3  - 27th International Conference on Fracture and Structural Integrity (IGF27)
T1  - Comparison of two recent approaches to DTB characterization of ferritic steels
EP  - 596
SP  - 589
VL  - 47
DO  - 10.1016/j.prostr.2023.07.065
ER  - 

@conference{
author = "Đorđević, Branislav and Mastilović, Sreten and Sedmak, Aleksandar and Dimić, Aleksandar and Sedmak, Simon and Aranđelović, Mihajlo",
year = "2023",
abstract = "The large scatter of the experimental fracture toughness data, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, imposed the need to include statistical methods for data processing. Due to the inherent stochasticity, the application of fracture mechanics concepts in the characterization of the DTB transition phenomenon has remained a challenging task over the past 50 years. Various models were developed based on statistical approach to data processing in order to capture the salient features of the phenomenon, but all of them have certain limitations because of the intrinsic complexity of the problem. However, all these models provided a solid basis for the continued development of new approaches in the characterization of DTB. Such two novel models are compared herein. They include size effects and utilize scaling of geometrically similar C(T) specimens, with the aim of obtaining predictions of the fracture toughness. Both proposed models have the weakest link statistics in common. In the present study, the EURO fracture toughness data set for 22NiMoCr37 reactor steel is used and the experimental data obtained at temperature of -60 °C is selected to demonstrate the accuracy of the estimates. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc [MPa√m]. The obtained predictions are in good agreement with the experimental results, taking into account the inherent scatter of the experimental data. The estimate of KJc cumulative distribution function obtained by extrapolation using the novel two-step-scaling method is sensitive to the statistical size of the input data sets.",
publisher = "Elsevier B.V.",
journal = "27th International Conference on Fracture and Structural Integrity (IGF27)",
title = "Comparison of two recent approaches to DTB characterization of ferritic steels",
pages = "596-589",
volume = "47",
doi = "10.1016/j.prostr.2023.07.065"
}

Đorđević, B., Mastilović, S., Sedmak, A., Dimić, A., Sedmak, S.,& Aranđelović, M.. (2023). Comparison of two recent approaches to DTB characterization of ferritic steels. in 27th International Conference on Fracture and Structural Integrity (IGF27)
Elsevier B.V.., 47, 589-596.
https://doi.org/10.1016/j.prostr.2023.07.065

Đorđević B, Mastilović S, Sedmak A, Dimić A, Sedmak S, Aranđelović M. Comparison of two recent approaches to DTB characterization of ferritic steels. in 27th International Conference on Fracture and Structural Integrity (IGF27). 2023;47:589-596.
doi:10.1016/j.prostr.2023.07.065 .

Đorđević, Branislav, Mastilović, Sreten, Sedmak, Aleksandar, Dimić, Aleksandar, Sedmak, Simon, Aranđelović, Mihajlo, "Comparison of two recent approaches to DTB characterization of ferritic steels" in 27th International Conference on Fracture and Structural Integrity (IGF27), 47 (2023):589-596,
https://doi.org/10.1016/j.prostr.2023.07.065 . .

TY  - CONF
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - http://www.ssm.kg.ac.rs/congress_2023/papers/
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7099
AB  - The fracture toughness of ferritic steels in the DTB (ductile-to-brittle) transition temperature
region is a stochastic extrinsic property known for pronounced experimental data scatter that
necessitates statistical approach in the DTB characterization. The novel two-step-scaling (2SS)
method, proposed recently for the size effect-modeling across the DTB transition region, is
developed based on the weakest-link statistics and the two-parametric Weibull distribution.
Specifically, the size sensitivity of the Weibull parameters of scale and shape are built into the
appropriate framework. This approach is upgraded in this article to render the comparison with
the existing models more transparent. Specifically, the original 2SS method is enhanced by
adding a lower limit on fracture toughness, resulting in the translated (three-parameter) Weibull
cumulative distribution function. This third Weibull parameter, often dubbed the location
parameter, defines a threshold value that limits the accessible fracture toughness domain. The
upgraded 2SS approach is compared to two established methods of the DTB fracture toughness
assessment, which favorably reflected upon its generality and application flexibility.
C3  - 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia
T1  - UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7099
ER  - 

@conference{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2023",
abstract = "The fracture toughness of ferritic steels in the DTB (ductile-to-brittle) transition temperature
region is a stochastic extrinsic property known for pronounced experimental data scatter that
necessitates statistical approach in the DTB characterization. The novel two-step-scaling (2SS)
method, proposed recently for the size effect-modeling across the DTB transition region, is
developed based on the weakest-link statistics and the two-parametric Weibull distribution.
Specifically, the size sensitivity of the Weibull parameters of scale and shape are built into the
appropriate framework. This approach is upgraded in this article to render the comparison with
the existing models more transparent. Specifically, the original 2SS method is enhanced by
adding a lower limit on fracture toughness, resulting in the translated (three-parameter) Weibull
cumulative distribution function. This third Weibull parameter, often dubbed the location
parameter, defines a threshold value that limits the accessible fracture toughness domain. The
upgraded 2SS approach is compared to two established methods of the DTB fracture toughness
assessment, which favorably reflected upon its generality and application flexibility.",
journal = "9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia",
title = "UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7099"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2023). UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.
https://hdl.handle.net/21.15107/rcub_machinery_7099

Mastilović S, Đorđević B, Sedmak A. UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia. 2023;.
https://hdl.handle.net/21.15107/rcub_machinery_7099 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS" in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia (2023),
https://hdl.handle.net/21.15107/rcub_machinery_7099 .

TY  - CONF
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Petrovski, Blagoj
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
PY  - 2023
UR  - http://cnntechno.com/docs/7_CNN_book_of_abstracts.pdf
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7095
AB  - In this paper is presented the 1-point method for material behaviour prediction, in terms of fracture toughness, of the ferritic steel EN 1.6310 in the transition temperature regime (-60°C and -90°C). Experiments were carried out at two different temperatures, representing two studies joined in one. Experimental testing was performed according to ASTM 1820 standard. This 1-point method is based on statistical processing (of 2-parameters Weibull statistics) of obtained experimental results, i.e. scattered J-integral values, of C(T) specimens with different geometries. Fixing value of one Weibull parameter and taking into account size-dependence of second one, fracture probabilities in the function of J-integral for large C(T)100 and C(T)200 were determined based on testing of C(T)50 specimen size. This research pointed out the sensitivty of proposed method on statistical sample size. One of the aims of proposed method was reducing the cost and price of laboratory tests in overall by predicting material behaviour and testing smaller C(T) specimen size. This research represents an upgrade of the Landes and Heerens works, and it is dedicated to their efforts in understanding and characterisation of transition temperature regime of ferritic steels.
PB  - University of Belgrade - Faculty of Mechanical Engineering
C3  - International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts
T1  - A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL
SP  - 21
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7095
ER  - 

@conference{
author = "Đorđević, Branislav and Mastilović, Sreten and Petrovski, Blagoj and Sedmak, Aleksandar and Dimić, Aleksandar",
year = "2023",
abstract = "In this paper is presented the 1-point method for material behaviour prediction, in terms of fracture toughness, of the ferritic steel EN 1.6310 in the transition temperature regime (-60°C and -90°C). Experiments were carried out at two different temperatures, representing two studies joined in one. Experimental testing was performed according to ASTM 1820 standard. This 1-point method is based on statistical processing (of 2-parameters Weibull statistics) of obtained experimental results, i.e. scattered J-integral values, of C(T) specimens with different geometries. Fixing value of one Weibull parameter and taking into account size-dependence of second one, fracture probabilities in the function of J-integral for large C(T)100 and C(T)200 were determined based on testing of C(T)50 specimen size. This research pointed out the sensitivty of proposed method on statistical sample size. One of the aims of proposed method was reducing the cost and price of laboratory tests in overall by predicting material behaviour and testing smaller C(T) specimen size. This research represents an upgrade of the Landes and Heerens works, and it is dedicated to their efforts in understanding and characterisation of transition temperature regime of ferritic steels.",
publisher = "University of Belgrade - Faculty of Mechanical Engineering",
journal = "International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts",
title = "A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL",
pages = "21",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7095"
}

Đorđević, B., Mastilović, S., Petrovski, B., Sedmak, A.,& Dimić, A.. (2023). A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL. in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts
University of Belgrade - Faculty of Mechanical Engineering., 21.
https://hdl.handle.net/21.15107/rcub_machinery_7095

Đorđević B, Mastilović S, Petrovski B, Sedmak A, Dimić A. A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL. in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts. 2023;:21.
https://hdl.handle.net/21.15107/rcub_machinery_7095 .

Đorđević, Branislav, Mastilović, Sreten, Petrovski, Blagoj, Sedmak, Aleksandar, Dimić, Aleksandar, "A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL" in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts (2023):21,
https://hdl.handle.net/21.15107/rcub_machinery_7095 .

TY  - CONF
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - http://www.ssm.kg.ac.rs/congress_2023/papers/
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7098
AB  - The ferritic steels, widely used as pressure-vessel materials in nuclear industry, are prone to
embrittlement when exposed to neutron irradiation or temperature reduction within the DTB
(ductile-to-brittle) transition region. This embrittlement may be accompanied by the increased
size effect, which is a pronounced consequence of fracture mechanics not exhibited in the
traditional plasticity theory. Therefore, the fracture toughness in the DTB transition temperature
region is a stochastic extrinsic property well known for its aleatory variability. Consequently, the
extremely-pronounced experimental data scatter necessitates the use of the statistical approach to
material characterization. The recently proposed two-step-scaling approach to estimate the size
effect of fracture toughness CDF (cumulative density function) in the DTB transition region relies
heavily on regularity of arrangement of experimental data points for the two input sample sizes.
This regularity of measurement values becomes an inherently iffy proposition in the case of
statistically small data sets. Therefore, the ability of our novel approach to predict objectively the
fracture toughness probability outside the experimental domain may be impaired in absence of the
sufficient statistical size of the input data sets. Since the large-scale fracture toughness tests for
nuclear pressure-vessel steels at low temperatures are very expensive, the present study is
concerned with this issue of the statistically sufficient sample size. There are various statistical
techniques to determine the sample size needed for a study, including power analysis and sample
size calculation formulas. The appropriate method depends on the type of study, the research
question, and the statistical analysis planned. These issues are addressed in this article.
C3  - 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.
T1  - A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7098
ER  - 

@conference{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2023",
abstract = "The ferritic steels, widely used as pressure-vessel materials in nuclear industry, are prone to
embrittlement when exposed to neutron irradiation or temperature reduction within the DTB
(ductile-to-brittle) transition region. This embrittlement may be accompanied by the increased
size effect, which is a pronounced consequence of fracture mechanics not exhibited in the
traditional plasticity theory. Therefore, the fracture toughness in the DTB transition temperature
region is a stochastic extrinsic property well known for its aleatory variability. Consequently, the
extremely-pronounced experimental data scatter necessitates the use of the statistical approach to
material characterization. The recently proposed two-step-scaling approach to estimate the size
effect of fracture toughness CDF (cumulative density function) in the DTB transition region relies
heavily on regularity of arrangement of experimental data points for the two input sample sizes.
This regularity of measurement values becomes an inherently iffy proposition in the case of
statistically small data sets. Therefore, the ability of our novel approach to predict objectively the
fracture toughness probability outside the experimental domain may be impaired in absence of the
sufficient statistical size of the input data sets. Since the large-scale fracture toughness tests for
nuclear pressure-vessel steels at low temperatures are very expensive, the present study is
concerned with this issue of the statistically sufficient sample size. There are various statistical
techniques to determine the sample size needed for a study, including power analysis and sample
size calculation formulas. The appropriate method depends on the type of study, the research
question, and the statistical analysis planned. These issues are addressed in this article.",
journal = "9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.",
title = "A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7098"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2023). A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia..
https://hdl.handle.net/21.15107/rcub_machinery_7098

Mastilović S, Đorđević B, Sedmak A. A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.. 2023;.
https://hdl.handle.net/21.15107/rcub_machinery_7098 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION" in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia. (2023),
https://hdl.handle.net/21.15107/rcub_machinery_7098 .

TY  - JOUR
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
AU  - Kljajin, Milan
PY  - 2023
UR  - https://www.sciencedirect.com/science/article/pii/S0013794423006744
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7107
AB  - The phenomenon of ductile-to-brittle transition in ferritic steels has been a ubiquitous research challenge for the last 50 years. The characterization of this problem using the fracture mechanics concept, from the earliest studies based on the linear-elastic fracture mechanics to the application of the elastic–plastic fracture mechanics, has become inevitable over time. The fracture toughness is not an intrinsic material property but depends on geometrical factors (such as the specimen shape, thickness, and surface roughness), defect type and distribution, loading mode, and environmental conditions. The pronounced scatter of experimental data on fracture toughness, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, necessitated the use of statistical methods for data processing. That approach, which emerged in the 1970 s, can still be found today as the basis for interpreting fracture toughness data in ductile-to-brittle transition problems. This paper presents a brief historical overview of such studies along with the problems that have arisen as a consequence of using fracture mechanics concepts, such as constraint effects, as an example. In the time-honored research tradition, all the proposed methods and models, as well as their criticisms, provided the basis for the development of new approaches to the ductile-to-brittle characterization of ferritic steels. Specifically, these include size effects and scaling of geometrically similar samples, with the aim of predicting material behavior beyond experimental limits. Brief outlines of two new approaches are provided in this succinct review. The criticisms of all presented methods are oriented mostly on the application domain, as well as their capability to predict fracture toughness, with short overview of their most conspicuous advantages and disadvantages.
T2  - Engineering Fracture Mechanics
T1  - Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends
SP  - 109716
VL  - 293
DO  - 10.1016/j.engfracmech.2023.109716
ER  - 

@article{
author = "Đorđević, Branislav and Mastilović, Sreten and Sedmak, Aleksandar and Dimić, Aleksandar and Kljajin, Milan",
year = "2023",
abstract = "The phenomenon of ductile-to-brittle transition in ferritic steels has been a ubiquitous research challenge for the last 50 years. The characterization of this problem using the fracture mechanics concept, from the earliest studies based on the linear-elastic fracture mechanics to the application of the elastic–plastic fracture mechanics, has become inevitable over time. The fracture toughness is not an intrinsic material property but depends on geometrical factors (such as the specimen shape, thickness, and surface roughness), defect type and distribution, loading mode, and environmental conditions. The pronounced scatter of experimental data on fracture toughness, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, necessitated the use of statistical methods for data processing. That approach, which emerged in the 1970 s, can still be found today as the basis for interpreting fracture toughness data in ductile-to-brittle transition problems. This paper presents a brief historical overview of such studies along with the problems that have arisen as a consequence of using fracture mechanics concepts, such as constraint effects, as an example. In the time-honored research tradition, all the proposed methods and models, as well as their criticisms, provided the basis for the development of new approaches to the ductile-to-brittle characterization of ferritic steels. Specifically, these include size effects and scaling of geometrically similar samples, with the aim of predicting material behavior beyond experimental limits. Brief outlines of two new approaches are provided in this succinct review. The criticisms of all presented methods are oriented mostly on the application domain, as well as their capability to predict fracture toughness, with short overview of their most conspicuous advantages and disadvantages.",
journal = "Engineering Fracture Mechanics",
title = "Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends",
pages = "109716",
volume = "293",
doi = "10.1016/j.engfracmech.2023.109716"
}

Đorđević, B., Mastilović, S., Sedmak, A., Dimić, A.,& Kljajin, M.. (2023). Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends. in Engineering Fracture Mechanics, 293, 109716.
https://doi.org/10.1016/j.engfracmech.2023.109716

Đorđević B, Mastilović S, Sedmak A, Dimić A, Kljajin M. Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends. in Engineering Fracture Mechanics. 2023;293:109716.
doi:10.1016/j.engfracmech.2023.109716 .

Đorđević, Branislav, Mastilović, Sreten, Sedmak, Aleksandar, Dimić, Aleksandar, Kljajin, Milan, "Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends" in Engineering Fracture Mechanics, 293 (2023):109716,
https://doi.org/10.1016/j.engfracmech.2023.109716 . .

TY  - JOUR
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
AU  - Kirin, Snežana
PY  - 2023
UR  - http://divk.inovacionicentar.rs/ivk/ivk23/OF2302-1.html
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7105
AB  - The phenomenon of ductile-to-brittle transition (DBT) in ferritic steels, widely used in design of nuclear reactor pressure vessels, has been a pervasive semi-centennial research topic. Due to the extremely pronounced experimental data scatter, the statistical approach to characterization of this problem has become inevitable from the earliest analyses. In the present study, the fracture toughness parameters derived from the EURO fracture toughness dataset for 22NiMoCr37 reactor steel are used with the aim to explore the utility of the recently proposed two-step-scaling method. Two widely different temperatures (-154 °C and -91 °C; belonging to the lower shelf and the DBT transition regions of fracture toughness, in respect) are selected to demonstrate the accuracy of extrapolation and interpolation of the fracture toughness CDF (cumulative distribution function) and the pertinent issues related to the method application. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc (MPa√m). The obtained predictions are in good agreement with the experimental results and well within the inherent experimental data scatter. The prediction of the fracture toughness CDF obtained by extrapolation using the novel two-step-scaling method is reasonably conservative.
PB  - Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd
T2  - Structural Integrity and Life -
T1  - SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD
EP  - 110
IS  - 2
SP  - 105
VL  - 23
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7105
ER  - 

@article{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar and Kirin, Snežana",
year = "2023",
abstract = "The phenomenon of ductile-to-brittle transition (DBT) in ferritic steels, widely used in design of nuclear reactor pressure vessels, has been a pervasive semi-centennial research topic. Due to the extremely pronounced experimental data scatter, the statistical approach to characterization of this problem has become inevitable from the earliest analyses. In the present study, the fracture toughness parameters derived from the EURO fracture toughness dataset for 22NiMoCr37 reactor steel are used with the aim to explore the utility of the recently proposed two-step-scaling method. Two widely different temperatures (-154 °C and -91 °C; belonging to the lower shelf and the DBT transition regions of fracture toughness, in respect) are selected to demonstrate the accuracy of extrapolation and interpolation of the fracture toughness CDF (cumulative distribution function) and the pertinent issues related to the method application. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc (MPa√m). The obtained predictions are in good agreement with the experimental results and well within the inherent experimental data scatter. The prediction of the fracture toughness CDF obtained by extrapolation using the novel two-step-scaling method is reasonably conservative.",
publisher = "Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd",
journal = "Structural Integrity and Life -",
title = "SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD",
pages = "110-105",
number = "2",
volume = "23",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7105"
}

Mastilović, S., Đorđević, B., Sedmak, A.,& Kirin, S.. (2023). SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD. in Structural Integrity and Life -
Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd., 23(2), 105-110.
https://hdl.handle.net/21.15107/rcub_machinery_7105

Mastilović S, Đorđević B, Sedmak A, Kirin S. SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD. in Structural Integrity and Life -. 2023;23(2):105-110.
https://hdl.handle.net/21.15107/rcub_machinery_7105 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, Kirin, Snežana, "SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD" in Structural Integrity and Life -, 23, no. 2 (2023):105-110,
https://hdl.handle.net/21.15107/rcub_machinery_7105 .

TY  - CONF
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
AU  - Mastilović, Sreten
AU  - Popović, Olivera
AU  - Kirin, Snežana
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6274
AB  - This paper presents a review of different approaches through history concerning DTB transition phenomenon of ferritic steels and their characterization using FM concept, from the earliest studies based on LEFM to the application of the EPFM concept. The large scattering of the experimental fracture toughness data, characteristic of all ferritic steels in the transition temperature region, has imposed the need of including statistical methods for data processing. Such approach that began in the 1970s can be encountered even nowadays as the base of fracture toughness data interpretation in DTB problems. An overview of studies with statistical interpretation of experimental data in the transition temperature region is also given. Aforementioned provides a foundation for novel approaches in DTB transition problems, which include size effects and scaling of geometrically similar specimens.
C3  - Procedia Structural Integrity
T1  - History of ductile-to-brittle transition problem of ferritic steels
EP  - 95
SP  - 88
VL  - 42
DO  - 10.1016/j.prostr.2022.12.010
ER  - 

@conference{
author = "Đorđević, Branislav and Sedmak, Aleksandar and Mastilović, Sreten and Popović, Olivera and Kirin, Snežana",
year = "2022",
abstract = "This paper presents a review of different approaches through history concerning DTB transition phenomenon of ferritic steels and their characterization using FM concept, from the earliest studies based on LEFM to the application of the EPFM concept. The large scattering of the experimental fracture toughness data, characteristic of all ferritic steels in the transition temperature region, has imposed the need of including statistical methods for data processing. Such approach that began in the 1970s can be encountered even nowadays as the base of fracture toughness data interpretation in DTB problems. An overview of studies with statistical interpretation of experimental data in the transition temperature region is also given. Aforementioned provides a foundation for novel approaches in DTB transition problems, which include size effects and scaling of geometrically similar specimens.",
journal = "Procedia Structural Integrity",
title = "History of ductile-to-brittle transition problem of ferritic steels",
pages = "95-88",
volume = "42",
doi = "10.1016/j.prostr.2022.12.010"
}

Đorđević, B., Sedmak, A., Mastilović, S., Popović, O.,& Kirin, S.. (2022). History of ductile-to-brittle transition problem of ferritic steels. in Procedia Structural Integrity, 42, 88-95.
https://doi.org/10.1016/j.prostr.2022.12.010

Đorđević B, Sedmak A, Mastilović S, Popović O, Kirin S. History of ductile-to-brittle transition problem of ferritic steels. in Procedia Structural Integrity. 2022;42:88-95.
doi:10.1016/j.prostr.2022.12.010 .

Đorđević, Branislav, Sedmak, Aleksandar, Mastilović, Sreten, Popović, Olivera, Kirin, Snežana, "History of ductile-to-brittle transition problem of ferritic steels" in Procedia Structural Integrity, 42 (2022):88-95,
https://doi.org/10.1016/j.prostr.2022.12.010 . .

TY  - JOUR
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6252
T2  - Engineering Failure Analysis
T1  - Corrigendum to “A scaling approach to size effect modeling of Jc CDF for 20MnMoNi55 reactor steel in transition temperature region”
SP  - 106751
VL  - 142
DO  - 10.1016/j.engfailanal.2022.106751
ER  - 

@article{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2022",
journal = "Engineering Failure Analysis",
title = "Corrigendum to “A scaling approach to size effect modeling of Jc CDF for 20MnMoNi55 reactor steel in transition temperature region”",
pages = "106751",
volume = "142",
doi = "10.1016/j.engfailanal.2022.106751"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2022). Corrigendum to “A scaling approach to size effect modeling of Jc CDF for 20MnMoNi55 reactor steel in transition temperature region”. in Engineering Failure Analysis, 142, 106751.
https://doi.org/10.1016/j.engfailanal.2022.106751

Mastilović S, Đorđević B, Sedmak A. Corrigendum to “A scaling approach to size effect modeling of Jc CDF for 20MnMoNi55 reactor steel in transition temperature region”. in Engineering Failure Analysis. 2022;142:106751.
doi:10.1016/j.engfailanal.2022.106751 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "Corrigendum to “A scaling approach to size effect modeling of Jc CDF for 20MnMoNi55 reactor steel in transition temperature region”" in Engineering Failure Analysis, 142 (2022):106751,
https://doi.org/10.1016/j.engfailanal.2022.106751 . .

TY  - JOUR
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav R.
AU  - Sedmak, Aleksandar
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3777
AB  - Ever since the 1980s there is a sustained interest in the size effect, as one of the most pronounced consequences of fracture mechanics. In the present study, the investigation of the size effect is focused on estimation of the Weibull cumulative distribution function (CDF) of the critical value of the J-integral (J(c)) in the transition temperature region under constraint of a small statistical sample size. Specifically, the J(c) experimental data correspond to the C(T) specimen testing of the reactor pressure-vessel steel 20MnMoNi55 at only two geometrically-similar sizes. Thus, a simple approximate scaling algorithm has been developed to tackle the effect of the C(T) specimen size on the J(c) CDF under these circumstances. Due to the specific form of the two-parameter Weibull CDF, F(J(c) vertical bar beta, eta), the scaling procedure is applied according to a two-step scheme. First, the J(c)-scaling is performed to ensure the approximate overlap of the points that correspond to the CDF value F(J(c) = eta) = 1 - 1/e approximate to 0.632 for different C(T) specimen widths (W), which assumes eta.W-kappa= const. Second, the F-scaling is performed to ensure the equality of the slopes of the CDF in the scaled (F.W(xi)vs. J(c).W-kappa) space. The objective of the sketched approach is to obtain a size-dependent J(c) CDF that encapsulates a reasonably conservative data extrapolation.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Engineering Failure Analysis
T1  - A scaling approach to size effect modeling of J(c) CDF for 20MnMoNi55 reactor steel in transition temperature region
VL  - 131
DO  - 10.1016/j.engfailanal.2021.105838
ER  - 

@article{
author = "Mastilović, Sreten and Đorđević, Branislav R. and Sedmak, Aleksandar",
year = "2022",
abstract = "Ever since the 1980s there is a sustained interest in the size effect, as one of the most pronounced consequences of fracture mechanics. In the present study, the investigation of the size effect is focused on estimation of the Weibull cumulative distribution function (CDF) of the critical value of the J-integral (J(c)) in the transition temperature region under constraint of a small statistical sample size. Specifically, the J(c) experimental data correspond to the C(T) specimen testing of the reactor pressure-vessel steel 20MnMoNi55 at only two geometrically-similar sizes. Thus, a simple approximate scaling algorithm has been developed to tackle the effect of the C(T) specimen size on the J(c) CDF under these circumstances. Due to the specific form of the two-parameter Weibull CDF, F(J(c) vertical bar beta, eta), the scaling procedure is applied according to a two-step scheme. First, the J(c)-scaling is performed to ensure the approximate overlap of the points that correspond to the CDF value F(J(c) = eta) = 1 - 1/e approximate to 0.632 for different C(T) specimen widths (W), which assumes eta.W-kappa= const. Second, the F-scaling is performed to ensure the equality of the slopes of the CDF in the scaled (F.W(xi)vs. J(c).W-kappa) space. The objective of the sketched approach is to obtain a size-dependent J(c) CDF that encapsulates a reasonably conservative data extrapolation.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Engineering Failure Analysis",
title = "A scaling approach to size effect modeling of J(c) CDF for 20MnMoNi55 reactor steel in transition temperature region",
volume = "131",
doi = "10.1016/j.engfailanal.2021.105838"
}

Mastilović, S., Đorđević, B. R.,& Sedmak, A.. (2022). A scaling approach to size effect modeling of J(c) CDF for 20MnMoNi55 reactor steel in transition temperature region. in Engineering Failure Analysis
Pergamon-Elsevier Science Ltd, Oxford., 131.
https://doi.org/10.1016/j.engfailanal.2021.105838

Mastilović S, Đorđević BR, Sedmak A. A scaling approach to size effect modeling of J(c) CDF for 20MnMoNi55 reactor steel in transition temperature region. in Engineering Failure Analysis. 2022;131.
doi:10.1016/j.engfailanal.2021.105838 .

Mastilović, Sreten, Đorđević, Branislav R., Sedmak, Aleksandar, "A scaling approach to size effect modeling of J(c) CDF for 20MnMoNi55 reactor steel in transition temperature region" in Engineering Failure Analysis, 131 (2022),
https://doi.org/10.1016/j.engfailanal.2021.105838 . .

TY  - CONF
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6361
AB  - Ever since the 1980s there have been a surge of interest in the size effect, as one of the most
pronounced consequences of fracture mechanics. In the present study, the investigation of the size
effect is focused on estimation of the Weibull CDF of the critical value of the J-integral (Jc) under
constraint of a small sample size in the transition temperatrure range. Specifically, the Jc
experimental data correspond to the CT specimen testing of the reactor pressure-vessel steel
20MnMoNi55 at only two sizes and temperature of 60°C. Thus, a simple approximate scaling
algorithm has been developed to tackle the effect of the CT specimen size on the J c CDF for such
small sample size. Due to the specific form of the two-parameter Weibull CDF, F(Jc  | β, η), the
scaling procedure is applied according to a two-step scheme. First, the J c -scaling is performed to
ensure the approximate overlap of the points that correspond to the CDF values F(Jc  = η) =
1 – 1/e ≈ 0.632 for different CT specimen widths (W), which assumes η·W κ  = const. Second, the F-scaling is performed to ensure the equality of the slopes of the CDF in the scaled (F·W ξ vs. J c ·W κ ) space. The objective of the sketched approach is to obtain a conservative estimate of J c CDF that encapsulates the CT specimen size.
C3  - 8th International Congress of the Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021
T1  - Size/Effect Modeling of Weibull Jc Cumulative Distribution Function Based on a Scalling Approach
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6361
ER  - 

@conference{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2021",
abstract = "Ever since the 1980s there have been a surge of interest in the size effect, as one of the most
pronounced consequences of fracture mechanics. In the present study, the investigation of the size
effect is focused on estimation of the Weibull CDF of the critical value of the J-integral (Jc) under
constraint of a small sample size in the transition temperatrure range. Specifically, the Jc
experimental data correspond to the CT specimen testing of the reactor pressure-vessel steel
20MnMoNi55 at only two sizes and temperature of 60°C. Thus, a simple approximate scaling
algorithm has been developed to tackle the effect of the CT specimen size on the J c CDF for such
small sample size. Due to the specific form of the two-parameter Weibull CDF, F(Jc  | β, η), the
scaling procedure is applied according to a two-step scheme. First, the J c -scaling is performed to
ensure the approximate overlap of the points that correspond to the CDF values F(Jc  = η) =
1 – 1/e ≈ 0.632 for different CT specimen widths (W), which assumes η·W κ  = const. Second, the F-scaling is performed to ensure the equality of the slopes of the CDF in the scaled (F·W ξ vs. J c ·W κ ) space. The objective of the sketched approach is to obtain a conservative estimate of J c CDF that encapsulates the CT specimen size.",
journal = "8th International Congress of the Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021",
title = "Size/Effect Modeling of Weibull Jc Cumulative Distribution Function Based on a Scalling Approach",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6361"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2021). Size/Effect Modeling of Weibull Jc Cumulative Distribution Function Based on a Scalling Approach. in 8th International Congress of the Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021.
https://hdl.handle.net/21.15107/rcub_machinery_6361

Mastilović S, Đorđević B, Sedmak A. Size/Effect Modeling of Weibull Jc Cumulative Distribution Function Based on a Scalling Approach. in 8th International Congress of the Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021. 2021;.
https://hdl.handle.net/21.15107/rcub_machinery_6361 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "Size/Effect Modeling of Weibull Jc Cumulative Distribution Function Based on a Scalling Approach" in 8th International Congress of the Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021 (2021),
https://hdl.handle.net/21.15107/rcub_machinery_6361 .