Advanced material modelling of concrete in Abaqus

Margalite Vilnay, Leon Chernin, D Cotsovos

    Research output: Contribution to conferencePaper

    Abstract

    Abaqus is a complex finite element (FE) package widely used in civil engineering practice. The choice of material models for concrete is limited in Abaqus to (i) the smeared cracking model, (ii) the brittle cracking mode and (iii) the damaged plasticity model. The smeared cracking model can handle only monotonic loading that limits the range of its applicability. The damaged plasticity model is by far most complex concrete model incorporated in Abaqus that can be used in any loading regime. However, it is not “user friendly”, includes multiple parameters and its calibration can be very challenging. Additionally, this model does not allow damaged elements to be deleted form the FE analysis. The brittle cracking model can be used in any loading regime and is very “user friendly” and easy to calibrate. The main disadvantage of this model is that it assumes linear elastic material behaviour in compression.
    In this paper the brittle cracking model is extended by introducing nonlinear compressive behaviour using the user subroutine VUSDFLD. This subroutine allows to redefine material properties at a material point as a function of a field variable such as stress, strain, temperature, etc. The field variable is updated at each analysis step and the value of the relevant material property is recalculated. The nonlinear compressive behaviour of concrete is introduced into the brittle crack model by formulating the modulus of elasticity of concrete (Ec) as a function of strain (ε). The Ec-ε relationship is derived using the stress-strain curve obtained based on FIB Model Code 2010. Additionally, the concrete material is modelled to be able to develop damage defined by the maximum strain and damaged elements are deleted from the FE model. The extended brittle crack model is used to examine strain rate effects and also to simulate a three point bending experiment, a standard brittle failure test and reinforced concrete columns under blast. In all cases the results favourably compared with those observed in experiments. Overall, the extended brittle crack model offers a robust reliable way for modelling of concrete.
    Original languageEnglish
    Publication statusPublished - 2017
    EventCONFAB 2017: The 2nd International Conference on Structural Safety under Fire & Blast Loading - London, United Kingdom
    Duration: 10 Sep 201712 Sep 2017

    Conference

    ConferenceCONFAB 2017
    Abbreviated titleCONFAB 2017
    CountryUnited Kingdom
    CityLondon
    Period10/09/1712/09/17

    Fingerprint

    Concretes
    Subroutines
    Cracks
    Plasticity
    Materials properties
    Stress-strain curves
    Civil engineering
    Reinforced concrete
    Strain rate
    Elasticity
    Compaction
    Elastic moduli
    Experiments
    Calibration
    Finite element method

    Cite this

    Vilnay, M., Chernin, L., & Cotsovos, D. (2017). Advanced material modelling of concrete in Abaqus. Paper presented at CONFAB 2017, London, United Kingdom.
    Vilnay, Margalite ; Chernin, Leon ; Cotsovos, D. / Advanced material modelling of concrete in Abaqus. Paper presented at CONFAB 2017, London, United Kingdom.
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    title = "Advanced material modelling of concrete in Abaqus",
    abstract = "Abaqus is a complex finite element (FE) package widely used in civil engineering practice. The choice of material models for concrete is limited in Abaqus to (i) the smeared cracking model, (ii) the brittle cracking mode and (iii) the damaged plasticity model. The smeared cracking model can handle only monotonic loading that limits the range of its applicability. The damaged plasticity model is by far most complex concrete model incorporated in Abaqus that can be used in any loading regime. However, it is not “user friendly”, includes multiple parameters and its calibration can be very challenging. Additionally, this model does not allow damaged elements to be deleted form the FE analysis. The brittle cracking model can be used in any loading regime and is very “user friendly” and easy to calibrate. The main disadvantage of this model is that it assumes linear elastic material behaviour in compression.In this paper the brittle cracking model is extended by introducing nonlinear compressive behaviour using the user subroutine VUSDFLD. This subroutine allows to redefine material properties at a material point as a function of a field variable such as stress, strain, temperature, etc. The field variable is updated at each analysis step and the value of the relevant material property is recalculated. The nonlinear compressive behaviour of concrete is introduced into the brittle crack model by formulating the modulus of elasticity of concrete (Ec) as a function of strain (ε). The Ec-ε relationship is derived using the stress-strain curve obtained based on FIB Model Code 2010. Additionally, the concrete material is modelled to be able to develop damage defined by the maximum strain and damaged elements are deleted from the FE model. The extended brittle crack model is used to examine strain rate effects and also to simulate a three point bending experiment, a standard brittle failure test and reinforced concrete columns under blast. In all cases the results favourably compared with those observed in experiments. Overall, the extended brittle crack model offers a robust reliable way for modelling of concrete.",
    author = "Margalite Vilnay and Leon Chernin and D Cotsovos",
    year = "2017",
    language = "English",
    note = "CONFAB 2017 : The 2nd International Conference on Structural Safety under Fire & Blast Loading, CONFAB 2017 ; Conference date: 10-09-2017 Through 12-09-2017",

    }

    Vilnay, M, Chernin, L & Cotsovos, D 2017, 'Advanced material modelling of concrete in Abaqus' Paper presented at CONFAB 2017, London, United Kingdom, 10/09/17 - 12/09/17, .

    Advanced material modelling of concrete in Abaqus. / Vilnay, Margalite; Chernin, Leon; Cotsovos, D.

    2017. Paper presented at CONFAB 2017, London, United Kingdom.

    Research output: Contribution to conferencePaper

    TY - CONF

    T1 - Advanced material modelling of concrete in Abaqus

    AU - Vilnay, Margalite

    AU - Chernin, Leon

    AU - Cotsovos, D

    PY - 2017

    Y1 - 2017

    N2 - Abaqus is a complex finite element (FE) package widely used in civil engineering practice. The choice of material models for concrete is limited in Abaqus to (i) the smeared cracking model, (ii) the brittle cracking mode and (iii) the damaged plasticity model. The smeared cracking model can handle only monotonic loading that limits the range of its applicability. The damaged plasticity model is by far most complex concrete model incorporated in Abaqus that can be used in any loading regime. However, it is not “user friendly”, includes multiple parameters and its calibration can be very challenging. Additionally, this model does not allow damaged elements to be deleted form the FE analysis. The brittle cracking model can be used in any loading regime and is very “user friendly” and easy to calibrate. The main disadvantage of this model is that it assumes linear elastic material behaviour in compression.In this paper the brittle cracking model is extended by introducing nonlinear compressive behaviour using the user subroutine VUSDFLD. This subroutine allows to redefine material properties at a material point as a function of a field variable such as stress, strain, temperature, etc. The field variable is updated at each analysis step and the value of the relevant material property is recalculated. The nonlinear compressive behaviour of concrete is introduced into the brittle crack model by formulating the modulus of elasticity of concrete (Ec) as a function of strain (ε). The Ec-ε relationship is derived using the stress-strain curve obtained based on FIB Model Code 2010. Additionally, the concrete material is modelled to be able to develop damage defined by the maximum strain and damaged elements are deleted from the FE model. The extended brittle crack model is used to examine strain rate effects and also to simulate a three point bending experiment, a standard brittle failure test and reinforced concrete columns under blast. In all cases the results favourably compared with those observed in experiments. Overall, the extended brittle crack model offers a robust reliable way for modelling of concrete.

    AB - Abaqus is a complex finite element (FE) package widely used in civil engineering practice. The choice of material models for concrete is limited in Abaqus to (i) the smeared cracking model, (ii) the brittle cracking mode and (iii) the damaged plasticity model. The smeared cracking model can handle only monotonic loading that limits the range of its applicability. The damaged plasticity model is by far most complex concrete model incorporated in Abaqus that can be used in any loading regime. However, it is not “user friendly”, includes multiple parameters and its calibration can be very challenging. Additionally, this model does not allow damaged elements to be deleted form the FE analysis. The brittle cracking model can be used in any loading regime and is very “user friendly” and easy to calibrate. The main disadvantage of this model is that it assumes linear elastic material behaviour in compression.In this paper the brittle cracking model is extended by introducing nonlinear compressive behaviour using the user subroutine VUSDFLD. This subroutine allows to redefine material properties at a material point as a function of a field variable such as stress, strain, temperature, etc. The field variable is updated at each analysis step and the value of the relevant material property is recalculated. The nonlinear compressive behaviour of concrete is introduced into the brittle crack model by formulating the modulus of elasticity of concrete (Ec) as a function of strain (ε). The Ec-ε relationship is derived using the stress-strain curve obtained based on FIB Model Code 2010. Additionally, the concrete material is modelled to be able to develop damage defined by the maximum strain and damaged elements are deleted from the FE model. The extended brittle crack model is used to examine strain rate effects and also to simulate a three point bending experiment, a standard brittle failure test and reinforced concrete columns under blast. In all cases the results favourably compared with those observed in experiments. Overall, the extended brittle crack model offers a robust reliable way for modelling of concrete.

    M3 - Paper

    ER -

    Vilnay M, Chernin L, Cotsovos D. Advanced material modelling of concrete in Abaqus. 2017. Paper presented at CONFAB 2017, London, United Kingdom.