本文讨论了混凝土非线性分析中的单元尺寸效应,并基于断裂能和钝裂缝带模型提出把开裂应变作为开裂位移与积分点单元特征长度的函数,应用于塑性损伤模型中,保证了断裂能的唯一性,有效地消除混凝土塑性损伤分析中的单元尺寸效应。利用本文开发的有限元程序对混凝土单轴受拉和koyna重力坝地震损伤分析的实例计算表明,本文提出的方法是有效可行的。
This paper discusses element-size effect on nonlinear analysis of concrete.Crack strain is considered as a function of crack displacement and element length at the integration point,and a model of fracture energy and blunt crack band is developed.This model is used to improve the plastic-damage model in ensuring the uniqueness of fracture energy and effectively eliminating the element-size effect on plastic damage analysis of concrete.Application of these models to a case study of koyna gravity dam shows that the proposed method is effective in simulation of concrete uniaxial tension and analysis of seismic damage.