动态荷载作用下细观混凝土的尺寸效应研究

Size Effect of Meso Concrete Under Dynamic Load

混凝土材料的尺寸效应问题是很复杂的但同时又非常重要。为了研究动态荷载作用下混凝土的尺寸效应,从数值试验出发,根据自行编制的程序,生成随机骨料模型,应用塑性损伤本构,数值计算了不同尺寸下混凝土的动态破坏强度。结果发现:在相同的加载速率下,随着试件尺寸的增大,材料的强度在增大,破坏位移也在增大;混凝土的动强度随应变率的增加而提高,当随着试件尺寸的增大时,其动强度的增大幅度更为明显。

Size effect of concrete materials is very complex and very important. In order to study the size effect of concrete under dynamic load, the numerical experiments were adopted in this research. Based on a program developed by the author a random aggregate generation model was developed. Based on the plastic damage constitutive theory the dynamic breaking strength of concrete at different sizes was numerically analyzed. The results show that at the same loading rate, with the increase of sample size the strength of the material in increasing damage displacement also increased. The dy- namic strength of concrete increases with the strain rate increase. Its dynamic strength increases significantly with the sample size increases.