大骨料混凝土率型内时损伤本构模型

以内时理论和损伤理论为框架,分析了骨料粒径和应变率效应对混凝土损伤的影响.建立了大骨料混凝土的率型内时损伤本构模型,并采用该模型进行多轴动态应力-应变曲线分析.与大骨料混凝土多轴动态试验数据对比结果显示数值与试验结果符合较好,说明该模型可作为大骨料混凝土动态性能研究的依据.最后,应用所提出的本构模型和未考虑大骨料因素的内时损伤本构模型对某混凝土拱坝进行非线性地震反应分析,结果表明,应变率和骨料粒径对于结构的强度和刚度影响较大,在分析中应得到重视.

Rate-dependent endochronic damage constitutive model for large aggregate concrete

Based on the theory of endochronic and damage mechanics, the effect of aggregate size and strain rate on the damage variables of concrete is analyzed. A rate-dependent endochronic damage constitutive model of large aggregate concrete is proposed. The proposed model is used to analyze the multiple axis dynamic stress-strain curves. Compared with experimental data it is shown that the analytical result is in good agreement with the experimental data, and it can be used as the basis for dynamic properties research of large aggregate concrete. Finally, nonlinear seismic responses of a concrete arch dam are analyzed with this model and the model of endochronic and damage mechanics with normal concrete. The experimental results show that the effect of strain rate and aggregate size on the strength and stiffness of concrete structures is remarkable and should be paid attention to in analysis.