A multiaxial constitutive model for concrete in the fire situation: Theoretical formulation

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:50

Article

Gernay, Thomas¹  Millard, Alain²  Franssen, Jean-Marc³ 

[1] Univ Liege, Dept Struct Engn, Natl Fund Sci Res, B-4000 Liege, Belgium

[2] CEA, LM2S, SEMT, DEN,DANS,DM2S, F-91191 Gif Sur Yvette, France

[3] Univ Liege, Dept Struct Engn, B-4000 Liege, Belgium

关键词: Thermomechanical processes;    Concrete;    Constitutive behavior;    Elastic-plastic material;    Damage model;    Fire;   

DOI  :  10.1016/j.ijsolstr.2013.07.013

来源: Elsevier

【 摘 要 】

This paper aims to develop a multiaxial concrete model for implementation in finite element software dedicated to the analysis of structures in fire. The need for proper concrete model remains a challenging task in structural fire engineering because of the complexity of the concrete mechanical behavior characterization and the severe requirements for the material models raised by the development of performance-based design. A fully three-dimensional model is developed based on the combination of elastoplasticity and damage theories. The state of damage in concrete, assumed isotropic, is modeled by means of a fourth order damage tensor to capture the unilateral effect. The concrete model comprises a limited number of parameters that can be identified by three simple tests at ambient temperature. At high temperatures, a generic transient creep model is included to take into account explicitly the effect of transient creep strain. The numerical implementation of the concrete model in a finite element software is presented and a series of numerical simulations are conducted for validation. The concrete behavior is accurately captured in a large range of temperature and stress states. A limitation appears when modeling the concrete post-peak behavior in highly confined stress states, due to the coupling assumption between damage and plasticity, but the considered levels of triaxial confinement are unusual stress states in structural concrete. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free