钢纤维对混凝土单轴受压损伤本构模型的影响

Effect of Steel Fiber on the Damage Constitutive Model of Concrete under Uniaxial Compression

基于Weibull统计分布理论和等效应变假设,推导出纤维混凝土（SFRC）受压损伤本构模型.为更好地描述钢纤维对混凝土受压损伤的影响,模型中引入考虑纤维体积分数与纤维几何特征的纤维因子.结合纤维混凝土单轴受压试验数据,对模型中的参数进行修正,并将修正后的理论曲线与试验曲线进行比较.为验证模型的有效性,分别选取压应变为1.5εpk,2.0εpk处的压应力试验值与预测值进行对比.结果表明：理论曲线与试验曲线吻合较好,该模型在压应变为0～1.5εpk时可有效地描述单轴受压状态下纤维混凝土的损伤扩展过程以及纤维对峰值应力后的混凝土受压性能的改善作用.

Based on the Weibull distribution and the hypothesis of strain equivalence, a damage model for steel fiber reinforced concrete（SFRC） was proposed. To describe the influence of fiber on the concrete compressive damage model better, a fiber factor considering the fiber volume fraction and fiber geometrical characteristic was introduced to the damage model. A series of uniaxial compression test was performed to modify the parameters of the damage model. Comparisons of the corrected theoretical curve and the experi- mental curves were performed. In order to verify the effectiveness of the damage model, comparisons of predicted compressive stress and measured compressive stress corresponding to the strain at 1.5εpk and 2.0εpk were performed respectively. The results show that the two curves are in very good agreement with each other. The damage model for SFRC is proved to be valid to describe the damage progress and residual compressive behaviour of SFRC under uniaxial compression at a range of 0- 1.5εpk.