基于试验非拟合混凝土本构方程

目的建立混凝土单轴拉伸和压缩应力-应变方程．方法基于混凝土单轴拉伸和压缩的试验数据，研究应力-应变变化规律，抛弃传统的拟合方法，直接由混凝土基本性能（初始弹性模量、峰值应力、峰值应变和应变软化性态）导出应力-应变方程．结果全程应力-应变方程由强化方程和软化方程给出，在峰值应力之前，强化方程为单调增且二阶导数为负的曲线，与试验结果曲线相符．在峰值应力之后，用不同的软化方程表示试验软化曲线．结论笔者提出的混凝土本构方程与很多实验数据相符，方程中的参数具有明显的力学意义，形式简单，便于理解，能很好的应用于混凝土本构关系的研究中．

Non-Fitting Concrete Constitutive Equation Based on Experiments

Based on experimental data of uni-axial tension and compression of concrete, variation law of stress-strain is studied and stress-strain equation is given directly using basic properties, such as initial elastic modulus, peak stress, peak strain and strain softened property. Whole stress-strain equation is composed by strength equation and softened equation. Before peak stress, the strength equation is of monotone increasing and the negative second order derivative curve. The curve is consistent with the experimental results. After peak stress, the softening curve is expressed with different equation. The equation presented by the authors is simple to understand and agrees with many experimental data. Since the parameters in the equation are of mechanical significant, the equation could be widely used.