论文部分内容阅读
混凝土是一种非均质的材料,在细观层次上将混凝土看作由骨料、砂浆和两者之间的界面组成的三相复合材料。本文在对混凝土进行单轴压缩试验的基础上,根据CT扫描图像反映的细观破损过程,分析了基于CT数平均值变化规律的特点;将混凝土材料的损伤过程进行了分段,提出了损伤变量的提取方法。随后结合试验得到的宏观应力应变曲线,经过拟合得到损伤变量与宏观应变的关系公式,建立了新的分段损伤演化方程及损伤本构模型。通过对比分析,验证了损伤变量的计算结果和试验结果整体吻合较好。以此深入研究了混凝土材料细观破损机理。
Concrete is an inhomogeneous material that, at the microscopic level, treats concrete as a three-phase composite composed of aggregate, mortar and the interface between the two. Based on the uniaxial compression test of concrete, based on the mesoscopic damage process reflected in the CT scan images, the variation characteristics of CT average value are analyzed. The damage process of concrete is segmented, and the damage Variable extraction method. Then the macroscopic stress-strain curve obtained by the experiment is combined to obtain the relationship formula between the damage variable and the macro-strain, and a new segment damage evolution equation and damage constitutive model are established. Through comparative analysis, it is verified that the calculation results of the damage variables are in good agreement with the experimental results as a whole. In order to further study the meso-damage mechanism of concrete materials.