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为研究混凝土在股役期间的材料特性,进行了不同应变速率下(10~(-5),10~(-4),10~(-3)和10~(-2)/s)的混凝土单轴受压试验,分析了混凝土材料基本力学特性,试验结果表明:随着应变速率的提高,峰值应力和初始弹性模量呈现增大的趋势,峰值应力的变化规律并不明显。基于Weibull和Lognormal统计分布理论,以及Lemaitre应变等效原理,引入应变速率因素,构建出混凝土材料分段式率型单轴受压损伤本构模型。依据试验数据,确定了所建立的率型损伤本构模型参数;给出了不同速率下混凝土单轴受压应力-应变和损伤变化规律曲线。结果表明:建立的混凝土率型本构模型能够反映不同应变速率下混凝土单轴受压损伤全过程。
In order to study the material properties of concrete during the bondage, the concrete with different strain rates (10 ~ (-5), 10 ~ (-4), 10 ~ (-3) and 10 ~ (-2) The uniaxial compression test analyzes the basic mechanical properties of concrete. The experimental results show that the peak stress and the initial elastic modulus increase with the increase of strain rate, and the variation of peak stress is not obvious. Based on the statistical distribution theory of Weibull and Lognormal and the equivalent principle of Lemaitre strain, strain rate factor was introduced to construct a constitutive model of single-axis compression damage of concrete material. Based on the experimental data, the parameters of constitutive model of rate damage are established. The curves of stress, strain and damage of concrete under different rates are given. The results show that the established rate constitutive model of concrete can reflect the whole process of uniaxial compressive damage of concrete under different strain rates.