模拟混凝土滞回行为的各向异性损伤模型

AN ANISOTROPIC DAMAGE MODEL FOR SIMULATING THE HYSTERETIC BEHAVIOR OF CONCRETE UNDER CYCLIC LOADING

  • 摘要: 该文引入相互独立的拉损伤、压损伤演化规律,分别描述受拉开裂和受压破碎导致的混凝土损伤行为,然后采用非线性卸载-线性重加载模拟滞回行为,建立了改进的各向异性损伤模型。该文还建议了模型关键参数的率定方法。应用该模型模拟混凝土受拉和拉-压往复加载试验,计算获得的应力-应变曲线与试验曲线具有良好的可比性,能够反映损伤导致的刚度退化、残余变形累积、加卸载滞回耗能行为以及微裂缝闭合引起的刚度恢复现象。算例结果表明,该模型适宜模拟往复加载下的混凝土非线性行为。

     

    Abstract: A modified anisotropic damage model is developed by introducing two independent damage evolution rules to simulate the distinct behaviors of concrete due to tensile cracking and compressive crushing. Herein, the hysteretic behavior under cyclic loading is modeled using nonlinear unloading-linear reloading stress branches. The calibrating method of key parameters is also proposed. Subsequently, the model is used to analyze the response of concrete under cyclic tension and tensile-low compressive load. The stress-strain curves calculated by the model are highly comparable to those obtained by the tests and they reflect the damage-induced stiffness degradation, accumulation of residual deformation, hysteretic energy dissipation and stiffness recovery effect due to crack closing. The numerical results show that the modified damage model is applicable to simulating the nonlinear behavior of concrete under cyclic loading.

     

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