曹胜涛, 李志山. 约束混凝土单轴弹塑性损伤本构模型[J]. 工程力学, 2017, 34(11): 116-125. DOI: 10.6052/j.issn.1000-4750.2016.07.0513
引用本文: 曹胜涛, 李志山. 约束混凝土单轴弹塑性损伤本构模型[J]. 工程力学, 2017, 34(11): 116-125. DOI: 10.6052/j.issn.1000-4750.2016.07.0513
CAO Sheng-tao, LI Zhi-shan. AN ELASTOPLASTIC DAMAGE CONSTITUTIVE MODEL FOR CONFINED CONCRETE UNDER UNIAXIAL LOAD[J]. Engineering Mechanics, 2017, 34(11): 116-125. DOI: 10.6052/j.issn.1000-4750.2016.07.0513
Citation: CAO Sheng-tao, LI Zhi-shan. AN ELASTOPLASTIC DAMAGE CONSTITUTIVE MODEL FOR CONFINED CONCRETE UNDER UNIAXIAL LOAD[J]. Engineering Mechanics, 2017, 34(11): 116-125. DOI: 10.6052/j.issn.1000-4750.2016.07.0513

约束混凝土单轴弹塑性损伤本构模型

AN ELASTOPLASTIC DAMAGE CONSTITUTIVE MODEL FOR CONFINED CONCRETE UNDER UNIAXIAL LOAD

  • 摘要: 该文通过采用混凝土三维弹塑性损伤模型和弧长法分析了钢筋混凝土单轴压缩过程中箍筋对混凝土的约束作用,得到了约束混凝土单轴抗压强度和延性增大系数。基于连续介质损伤力学的基本框架,引入约束混凝土强度和延性增大系数,建立了混凝土单轴弹塑性损伤本构模型。验证表明:该文模型符合热动力基本方程,可较好地反映约束混凝土强度和延性增大、强度软化、刚度退化、塑性变形、裂面效应、等力学特性;模型参数与中国现行《混凝土结构设计规范》推荐的模型完全相同,易于工程应用。将该文模型与纤维束形式的Timoshenko梁单元相结合,在自主研发的结构非线性分析软件SAUSAGE中完成开发实现。利用SAUSAGE完成了某钢筋混凝土框架结构的大震动力非线性分析,结果表明:箍筋约束作用可以有效抑制梁、柱构件的非线性发展,影响了结构最大层间位移角和最大层间剪力等宏观指标。

     

    Abstract: A three-dimensional elastoplastic damage constitutive model for concrete and the arc-length method are used to analyze the confining effect of stirrups in reinforced concrete under uniaxial compression. The uniaxial compressive strength and ductility increasing coefficients of confined concrete are then obtained. Based on the framework of damage mechanics of continuous media, the uniaxial compressive strength and ductility increasing coefficients of confined concrete are introduced. An elastoplastic damage constitutive model for confined concrete under uniaxial load is proposed. The analysis showed that the proposed model was in accordance with the thermodynamic equation. In addition, the increase of strength and ductility, strength softening, stiffness degradation, residual deformation, and crack effect of confined concrete can be obtained by the proposed model. The parameters of the proposed model use the same parameters of the constitutive model in the concrete design code. Therefore, the proposed model is suitable for engineering applications. The proposed model combined with fiber Timoshenko beam elements is implemented in the structural nonlinear analysis software package ‘SAUSAGE’ by independent development. A reinforced concrete frame is analyzed by SAUSAGE. The results show that the confining effect of stirrups could effectively restrain the development of nonlinearity of beam and column members, and reduce the global indexes such as the maximum story drift ratios and maximum story shear force.

     

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