TY  - JOUR
AU  - Kostić, Svetlana
AU  - Filippou, Filip C.
PY  - 2023
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/3010
AB  - The paper presents an adaptive section discretization scheme for the inelastic response analysis of structural members with cross sections that can be decomposed into rectangular and circular subdomains. Each subdomain can consist of a different material. As long as the largest strain in a subdomain does not exceed the specified trigger strain values, the subdomain contribution to the section response is determined by the numerically exact cubature rule for the subdomain. Once the largest strain reaches the trigger value for a subdomain, it is discretized with a fiber mesh and the numerical evaluation of its contribution to the section response is determined with the midpoint
integration rule. The fiber mesh with the midpoint integration rule remains in effect for the activated subdomain until the end of the response history. The paper applies the adaptive discretization scheme to the thin-walled sections common in metallic structures and investigates the effect of different trigger strain values on the accuracy and computational efficiency of the inelastic response analysis of wide-flange steel sections and multistory steel frames under static and dynamic excitations.
T2  - Journal of Structural Engineering
T1  - An Adaptive Section Discretization Scheme for the Nonlinear Dynamic Analysis of Steel Frames
VL  - 149
DO  - 10.1061/JSENDH.STENG-11779
ER  - 

@article{
author = "Kostić, Svetlana and Filippou, Filip C.",
year = "2023",
abstract = "The paper presents an adaptive section discretization scheme for the inelastic response analysis of structural members with cross sections that can be decomposed into rectangular and circular subdomains. Each subdomain can consist of a different material. As long as the largest strain in a subdomain does not exceed the specified trigger strain values, the subdomain contribution to the section response is determined by the numerically exact cubature rule for the subdomain. Once the largest strain reaches the trigger value for a subdomain, it is discretized with a fiber mesh and the numerical evaluation of its contribution to the section response is determined with the midpoint
integration rule. The fiber mesh with the midpoint integration rule remains in effect for the activated subdomain until the end of the response history. The paper applies the adaptive discretization scheme to the thin-walled sections common in metallic structures and investigates the effect of different trigger strain values on the accuracy and computational efficiency of the inelastic response analysis of wide-flange steel sections and multistory steel frames under static and dynamic excitations.",
journal = "Journal of Structural Engineering",
title = "An Adaptive Section Discretization Scheme for the Nonlinear Dynamic Analysis of Steel Frames",
volume = "149",
doi = "10.1061/JSENDH.STENG-11779"
}

Kostić, S.,& Filippou, F. C.. (2023). An Adaptive Section Discretization Scheme for the Nonlinear Dynamic Analysis of Steel Frames. in Journal of Structural Engineering, 149.
https://doi.org/10.1061/JSENDH.STENG-11779

Kostić S, Filippou FC. An Adaptive Section Discretization Scheme for the Nonlinear Dynamic Analysis of Steel Frames. in Journal of Structural Engineering. 2023;149.
doi:10.1061/JSENDH.STENG-11779 .

Kostić, Svetlana, Filippou, Filip C., "An Adaptive Section Discretization Scheme for the Nonlinear Dynamic Analysis of Steel Frames" in Journal of Structural Engineering, 149 (2023),
https://doi.org/10.1061/JSENDH.STENG-11779 . .

TY  - CONF
AU  - Kostić, Svetlana
AU  - Filippou, Filip C.
PY  - 2022
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2824
AB  - The paper summarises a family of adaptive fiber section discretization schemesfor nonlinear frame elements. The proposed schemes use cubature integration rules forintegration within the linear-elastic part of a section and continuously increase the numberof section integration points with growing plastic deformations. Consequently, the algorithmimproves section integration using the optimal number of integration points, which results inconsiderably reduced analysis time and better computational efficiency. On the other side,the proposed discretizations keep the numerical accuracy of the regular fiber sectiondiscretization schemes. The algorithm is provided for full (homogeneous and composite)and thin-walled cross-sections. Depending on the type of analysis, the reduction in analysistime goes from 30% to 85% compared to the regular discretization. The savings achievedusing these adaptive section discretizations are especially valuable when several hundreds ofnonlinear time history analyses need to be performed.
C3  - Conference: Third European Conference on Earthquake Engineering and Seismology
T1  - Efficient Adaptive Section Discretization Schemes
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2824
ER  - 

@conference{
author = "Kostić, Svetlana and Filippou, Filip C.",
year = "2022",
abstract = "The paper summarises a family of adaptive fiber section discretization schemesfor nonlinear frame elements. The proposed schemes use cubature integration rules forintegration within the linear-elastic part of a section and continuously increase the numberof section integration points with growing plastic deformations. Consequently, the algorithmimproves section integration using the optimal number of integration points, which results inconsiderably reduced analysis time and better computational efficiency. On the other side,the proposed discretizations keep the numerical accuracy of the regular fiber sectiondiscretization schemes. The algorithm is provided for full (homogeneous and composite)and thin-walled cross-sections. Depending on the type of analysis, the reduction in analysistime goes from 30% to 85% compared to the regular discretization. The savings achievedusing these adaptive section discretizations are especially valuable when several hundreds ofnonlinear time history analyses need to be performed.",
journal = "Conference: Third European Conference on Earthquake Engineering and Seismology",
title = "Efficient Adaptive Section Discretization Schemes",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2824"
}

Kostić, S.,& Filippou, F. C.. (2022). Efficient Adaptive Section Discretization Schemes. in Conference: Third European Conference on Earthquake Engineering and Seismology.
https://hdl.handle.net/21.15107/rcub_grafar_2824

Kostić S, Filippou FC. Efficient Adaptive Section Discretization Schemes. in Conference: Third European Conference on Earthquake Engineering and Seismology. 2022;.
https://hdl.handle.net/21.15107/rcub_grafar_2824 .

Kostić, Svetlana, Filippou, Filip C., "Efficient Adaptive Section Discretization Schemes" in Conference: Third European Conference on Earthquake Engineering and Seismology (2022),
https://hdl.handle.net/21.15107/rcub_grafar_2824 .

TY  - CONF
AU  - Kostić, Svetlana
AU  - Filippou, Filip C.
PY  - 2019
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/3033
C3  - The 16th International Conference on Civil, Structural & Environmental Engineering Computing, Riva del Garda, Italy
T1  - Efficient discretization of circular cross-section in fiber beam/column element
UR  - https://hdl.handle.net/21.15107/rcub_grafar_3033
ER  - 

@conference{
author = "Kostić, Svetlana and Filippou, Filip C.",
year = "2019",
journal = "The 16th International Conference on Civil, Structural & Environmental Engineering Computing, Riva del Garda, Italy",
title = "Efficient discretization of circular cross-section in fiber beam/column element",
url = "https://hdl.handle.net/21.15107/rcub_grafar_3033"
}

Kostić, S.,& Filippou, F. C.. (2019). Efficient discretization of circular cross-section in fiber beam/column element. in The 16th International Conference on Civil, Structural & Environmental Engineering Computing, Riva del Garda, Italy.
https://hdl.handle.net/21.15107/rcub_grafar_3033

Kostić S, Filippou FC. Efficient discretization of circular cross-section in fiber beam/column element. in The 16th International Conference on Civil, Structural & Environmental Engineering Computing, Riva del Garda, Italy. 2019;.
https://hdl.handle.net/21.15107/rcub_grafar_3033 .

Kostić, Svetlana, Filippou, Filip C., "Efficient discretization of circular cross-section in fiber beam/column element" in The 16th International Conference on Civil, Structural & Environmental Engineering Computing, Riva del Garda, Italy (2019),
https://hdl.handle.net/21.15107/rcub_grafar_3033 .

TY  - JOUR
AU  - Kostić, Svetlana M.
AU  - Filippou, Filip C.
AU  - Deretić-Stojanović, Biljana
PY  - 2016
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/772
AB  - This paper presents a nonlinear 3d concentrated plasticity beam column element for the analysis of RCFT columns. The element consists of a linear elastic component with a plastic hinge at each end whose inelastic response is described by extending the concept of generalized plasticity to stress resultants. With independent yield and limit surfaces it is possible to describe the gradual yielding of composite sections and their post-yield hardening behavior. The geometric nonlinearity under large displacements is accounted for with the corotational formulation. The paper discusses the calibration of the model parameters and assesses the accuracy of the model through correlation studies.
PB  - Elsevier Ltd
T2  - Computers & Structures
T1  - Generalized plasticity model for inelastic RCFT column response
EP  - 67
SP  - 56
VL  - 168
DO  - 10.1016/j.compstruc.2016.02.006
ER  - 

@article{
author = "Kostić, Svetlana M. and Filippou, Filip C. and Deretić-Stojanović, Biljana",
year = "2016",
abstract = "This paper presents a nonlinear 3d concentrated plasticity beam column element for the analysis of RCFT columns. The element consists of a linear elastic component with a plastic hinge at each end whose inelastic response is described by extending the concept of generalized plasticity to stress resultants. With independent yield and limit surfaces it is possible to describe the gradual yielding of composite sections and their post-yield hardening behavior. The geometric nonlinearity under large displacements is accounted for with the corotational formulation. The paper discusses the calibration of the model parameters and assesses the accuracy of the model through correlation studies.",
publisher = "Elsevier Ltd",
journal = "Computers & Structures",
title = "Generalized plasticity model for inelastic RCFT column response",
pages = "67-56",
volume = "168",
doi = "10.1016/j.compstruc.2016.02.006"
}

Kostić, S. M., Filippou, F. C.,& Deretić-Stojanović, B.. (2016). Generalized plasticity model for inelastic RCFT column response. in Computers & Structures
Elsevier Ltd., 168, 56-67.
https://doi.org/10.1016/j.compstruc.2016.02.006

Kostić SM, Filippou FC, Deretić-Stojanović B. Generalized plasticity model for inelastic RCFT column response. in Computers & Structures. 2016;168:56-67.
doi:10.1016/j.compstruc.2016.02.006 .

Kostić, Svetlana M., Filippou, Filip C., Deretić-Stojanović, Biljana, "Generalized plasticity model for inelastic RCFT column response" in Computers & Structures, 168 (2016):56-67,
https://doi.org/10.1016/j.compstruc.2016.02.006 . .

TY  - JOUR
AU  - Kostić, Svetlana M.
AU  - Filippou, Filip C.
AU  - Lee, C.-L.
PY  - 2013
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/547
AB  - Beam-column elements with section resultant plasticity for the hysteretic behavior of the end plastic hinges are widely used for numerical simulations in earthquake engineering practice because of the good compromise between accuracy and computational cost. This chapter presents a three-dimensional inelastic beamcolumn element of this type with significant capabilities for the description of the global and local response of frames under monotonic and cyclic loads. In the proposed element the concept of generalized plasticity is extended to section resultants and element deformations and is used to describe the hysteretic behavior of the plastic hinges forming at the element ends. The element accounts for the interaction of the axial force with the bending moments about the principal section axes with suitably defined yield and limit surfaces that permit the description of the gradual yielding and the post-yield hardening behavior of the end sections. Comparisons of the hysteretic response of structural elements and small structural models between the proposed element and the more accurate, but computationally more expensive fiber section description of the cross section demonstrate the capabilities of the proposed model.
PB  - Springer Netherland
T2  - Computational Methods in Applied Sciences
T1  - An efficient beam-column element for inelastic 3D frame analysis
EP  - 67
SP  - 49
VL  - 30
DO  - 10.1007/978-94-007-6573-3_3
ER  - 

@article{
author = "Kostić, Svetlana M. and Filippou, Filip C. and Lee, C.-L.",
year = "2013",
abstract = "Beam-column elements with section resultant plasticity for the hysteretic behavior of the end plastic hinges are widely used for numerical simulations in earthquake engineering practice because of the good compromise between accuracy and computational cost. This chapter presents a three-dimensional inelastic beamcolumn element of this type with significant capabilities for the description of the global and local response of frames under monotonic and cyclic loads. In the proposed element the concept of generalized plasticity is extended to section resultants and element deformations and is used to describe the hysteretic behavior of the plastic hinges forming at the element ends. The element accounts for the interaction of the axial force with the bending moments about the principal section axes with suitably defined yield and limit surfaces that permit the description of the gradual yielding and the post-yield hardening behavior of the end sections. Comparisons of the hysteretic response of structural elements and small structural models between the proposed element and the more accurate, but computationally more expensive fiber section description of the cross section demonstrate the capabilities of the proposed model.",
publisher = "Springer Netherland",
journal = "Computational Methods in Applied Sciences",
title = "An efficient beam-column element for inelastic 3D frame analysis",
pages = "67-49",
volume = "30",
doi = "10.1007/978-94-007-6573-3_3"
}

Kostić, S. M., Filippou, F. C.,& Lee, C.-L.. (2013). An efficient beam-column element for inelastic 3D frame analysis. in Computational Methods in Applied Sciences
Springer Netherland., 30, 49-67.
https://doi.org/10.1007/978-94-007-6573-3_3

Kostić SM, Filippou FC, Lee C. An efficient beam-column element for inelastic 3D frame analysis. in Computational Methods in Applied Sciences. 2013;30:49-67.
doi:10.1007/978-94-007-6573-3_3 .

Kostić, Svetlana M., Filippou, Filip C., Lee, C.-L., "An efficient beam-column element for inelastic 3D frame analysis" in Computational Methods in Applied Sciences, 30 (2013):49-67,
https://doi.org/10.1007/978-94-007-6573-3_3 . .

TY  - CONF
AU  - Kostić, Svetlana M.
AU  - Filippou, Filip C.
AU  - Deretić-Stojanović, Biljana
PY  - 2013
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/548
AB  - In the paper, an efficient three-dimensional concentrated plasticity nonlinear beam-column element is used for the simulation of the response of square CFT columns. The element adopts the concept of the generalized plasticity material model for the section resultant - element deformation relation and has plastic hinges located at the ends of the element and described with yield and limit surfaces. Determination of the adequate element parameters which are essential for a successful description of the CFT member behavior is discussed. Among these parameters, most important are the stiffness and yield surface parameters.
PB  - National Technical University of Athens
C3  - ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in
T1  - Applcation of generalized plasticity model in square CFT column analysis
EP  - 3535
SP  - 3523
UR  - https://hdl.handle.net/21.15107/rcub_grafar_548
ER  - 

@conference{
author = "Kostić, Svetlana M. and Filippou, Filip C. and Deretić-Stojanović, Biljana",
year = "2013",
abstract = "In the paper, an efficient three-dimensional concentrated plasticity nonlinear beam-column element is used for the simulation of the response of square CFT columns. The element adopts the concept of the generalized plasticity material model for the section resultant - element deformation relation and has plastic hinges located at the ends of the element and described with yield and limit surfaces. Determination of the adequate element parameters which are essential for a successful description of the CFT member behavior is discussed. Among these parameters, most important are the stiffness and yield surface parameters.",
publisher = "National Technical University of Athens",
journal = "ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in",
title = "Applcation of generalized plasticity model in square CFT column analysis",
pages = "3535-3523",
url = "https://hdl.handle.net/21.15107/rcub_grafar_548"
}

Kostić, S. M., Filippou, F. C.,& Deretić-Stojanović, B.. (2013). Applcation of generalized plasticity model in square CFT column analysis. in ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in
National Technical University of Athens., 3523-3535.
https://hdl.handle.net/21.15107/rcub_grafar_548

Kostić SM, Filippou FC, Deretić-Stojanović B. Applcation of generalized plasticity model in square CFT column analysis. in ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in. 2013;:3523-3535.
https://hdl.handle.net/21.15107/rcub_grafar_548 .

Kostić, Svetlana M., Filippou, Filip C., Deretić-Stojanović, Biljana, "Applcation of generalized plasticity model in square CFT column analysis" in ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in (2013):3523-3535,
https://hdl.handle.net/21.15107/rcub_grafar_548 .

TY  - JOUR
AU  - Kostić, Svetlana M.
AU  - Filippou, Filip C.
PY  - 2012
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/454
AB  - The paper presents studies of the effect of the number of material integration points at the monitored sections of fiber beam-column elements on the local response of typical structural cross sections under an extensive set of cyclic biaxial load conditions with constant and variable axial load. The study covers wide-flange steel sections and rectangular reinforced concrete sections. The integration over the section uses the midpoint rule and shows that a standard section discretization with relatively few fibers is a good compromise between accuracy and economy of means. The proposed coarse section discretization schemes are computationally efficient while ensuring the accurate representation of important aspects of the three-dimensional response of structural members, such as interaction of axial force with biaxial bending moment, effect of residual stress in steel members, and effect of cracking in reinforced concrete members. The local strain response is also represented with good accuracy by the coarse discretization schemes. DOI: 10.1061/(ASCE)ST.1943-541X.0000501.
T2  - Journal of Structural Engineering-Asce
T1  - Section Discretization of Fiber Beam-Column Elements for Cyclic Inelastic Response
EP  - 601
IS  - 5
SP  - 592
VL  - 138
DO  - 10.1061/(ASCE)ST.1943-541X.0000501
ER  - 

@article{
author = "Kostić, Svetlana M. and Filippou, Filip C.",
year = "2012",
abstract = "The paper presents studies of the effect of the number of material integration points at the monitored sections of fiber beam-column elements on the local response of typical structural cross sections under an extensive set of cyclic biaxial load conditions with constant and variable axial load. The study covers wide-flange steel sections and rectangular reinforced concrete sections. The integration over the section uses the midpoint rule and shows that a standard section discretization with relatively few fibers is a good compromise between accuracy and economy of means. The proposed coarse section discretization schemes are computationally efficient while ensuring the accurate representation of important aspects of the three-dimensional response of structural members, such as interaction of axial force with biaxial bending moment, effect of residual stress in steel members, and effect of cracking in reinforced concrete members. The local strain response is also represented with good accuracy by the coarse discretization schemes. DOI: 10.1061/(ASCE)ST.1943-541X.0000501.",
journal = "Journal of Structural Engineering-Asce",
title = "Section Discretization of Fiber Beam-Column Elements for Cyclic Inelastic Response",
pages = "601-592",
number = "5",
volume = "138",
doi = "10.1061/(ASCE)ST.1943-541X.0000501"
}

Kostić, S. M.,& Filippou, F. C.. (2012). Section Discretization of Fiber Beam-Column Elements for Cyclic Inelastic Response. in Journal of Structural Engineering-Asce, 138(5), 592-601.
https://doi.org/10.1061/(ASCE)ST.1943-541X.0000501

Kostić SM, Filippou FC. Section Discretization of Fiber Beam-Column Elements for Cyclic Inelastic Response. in Journal of Structural Engineering-Asce. 2012;138(5):592-601.
doi:10.1061/(ASCE)ST.1943-541X.0000501 .

Kostić, Svetlana M., Filippou, Filip C., "Section Discretization of Fiber Beam-Column Elements for Cyclic Inelastic Response" in Journal of Structural Engineering-Asce, 138, no. 5 (2012):592-601,
https://doi.org/10.1061/(ASCE)ST.1943-541X.0000501 . .

TY  - CONF
AU  - Kostić, Svetlana M.
AU  - Filippou, Filip C.
AU  - Lee, C.-L.
PY  - 2011
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/375
AB  - A three-dimensional nonlinear beam-column element for the simulation of the global and local response of frames under monotonic and cyclic loading conditions is pre-sented. The element belongs to the group of concentrated plasticity models, with plastic hinges located at the ends of the element and described with yield and limit surfaces. The concept of generalized plasticity, originally developed for material plasticity, is extended to force resultants in the element formulation. The element takes into account the interaction of the axial force and the bending moments about the principal axes of the cross section and the hardening behavior. The gradual yielding of the cross section is described by the asymptoti-cal approaching of the limit surface.
C3  - ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in
T1  - An efficient beam-column element for nonlinear 3D frame analysis
UR  - https://hdl.handle.net/21.15107/rcub_grafar_375
ER  - 

@conference{
author = "Kostić, Svetlana M. and Filippou, Filip C. and Lee, C.-L.",
year = "2011",
abstract = "A three-dimensional nonlinear beam-column element for the simulation of the global and local response of frames under monotonic and cyclic loading conditions is pre-sented. The element belongs to the group of concentrated plasticity models, with plastic hinges located at the ends of the element and described with yield and limit surfaces. The concept of generalized plasticity, originally developed for material plasticity, is extended to force resultants in the element formulation. The element takes into account the interaction of the axial force and the bending moments about the principal axes of the cross section and the hardening behavior. The gradual yielding of the cross section is described by the asymptoti-cal approaching of the limit surface.",
journal = "ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in",
title = "An efficient beam-column element for nonlinear 3D frame analysis",
url = "https://hdl.handle.net/21.15107/rcub_grafar_375"
}

Kostić, S. M., Filippou, F. C.,& Lee, C.-L.. (2011). An efficient beam-column element for nonlinear 3D frame analysis. in ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in.
https://hdl.handle.net/21.15107/rcub_grafar_375

Kostić SM, Filippou FC, Lee C. An efficient beam-column element for nonlinear 3D frame analysis. in ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in. 2011;.
https://hdl.handle.net/21.15107/rcub_grafar_375 .

Kostić, Svetlana M., Filippou, Filip C., Lee, C.-L., "An efficient beam-column element for nonlinear 3D frame analysis" in ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in (2011),
https://hdl.handle.net/21.15107/rcub_grafar_375 .