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Communication Dans Un Congrès Année : 2019

Development of a Novel Damage Model for Concrete Subjected to High Temperature and Constraint

Résumé

Concrete exhibits visco-plastic behaviour when subjected to high temperature whilst supporting an external load; this component of plasticity is referred to as load induced thermal strain (LITS), which is also known as transient thermal creep (TTC). LITS phenomena can be important in pre-stressed concrete structures, because the evolution of LITS can potentially lead to a loss in pre-stress, and also residual tensile stress development under transient thermal conditions. Hence, structures which have been subjected to a high temperature thermal loading cycle may experience cracking and subsequent loss of rigidity; this could ultimately lead to a loss of functionality or even structural failure. Whilst models for LITS have only recently become available in the public domain, there are currently no available models that can capture cracking with plasticity, to an acceptable industrial reliability. Indeed, most damage models available in commercial packages do not adequately capture anisotropy and plasticity in addition to the unilateral effect exhibited by concrete, i.e. the Mazars damage model. However, recent research has led to the development of the Fichant-La Borderie (FLB) damage model, which has shown that these additional effects can be captured using an energy regularisation method; this makes the FLB model suitable to capture cracking due to LITS effects. In this project a method for coupling LITS behaviour with a FLB model is proposed. The constitutive behaviour is coupled to the damage law via the total stress tensor. By decomposing the visco-plastic and thermal strains, the damage evolution is driven from the elastic strains only. Finally, the effective stress is computed and used to obtain the total stress at each iteration with unilateral effect included. This type of model is most suitable for fully implicit integration schemes and will allow more accurate assessment of structural damage from transient thermal events, such as fire.
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Dates et versions

cea-02614126 , version 1 (20-05-2020)

Identifiants

  • HAL Id : cea-02614126 , version 1

Citer

J. Draup, A. Gangnant, G. Colette, G. Doughty, J. Guo, et al.. Development of a Novel Damage Model for Concrete Subjected to High Temperature and Constraint. SMiRT 25 - 25th International Conference on Structural Mechanics in Reactor Technology, Aug 2019, Charlotte, United States. ⟨cea-02614126⟩
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