混凝土复合型裂缝的断裂能及其判据研究

首先通过理论分析得到断裂能与能量释放率的关系,继而根据试验研究测出的单一型裂缝的断裂能,进行单一型裂缝断裂能与断裂韧度的相关性分析,得到了单一型裂缝的断裂能与能量释放率之间的关系,再进行数值模拟,获得混凝土复合型裂缝的断裂能。基于Ⅰ型、Ⅱ型、Ⅲ型、二维复合型(Ⅰ-Ⅱ、Ⅰ-Ⅲ、Ⅱ-Ⅲ)和三维复合型(Ⅰ-Ⅱ-Ⅲ)的应力强度因子断裂临界曲线和临界曲面(即完整的系列K判据),通过各复合型裂缝的断裂韧度,得到相应的能量释放率,进而获得复合型裂缝的断裂能,绘出断裂能临界曲线和曲面,从而建立了完整的系列断裂能G判据。

Research on Fracture Energy of Mixed Mode Crack in Concrete and Its Criteria

Through theoretical analysis,this paper presents the relationship between fracture energy and energy release rate.According to fracture energy of single-mode crack measured in test research,the correlation analysis between fracture energy of single-mode crack and fracture toughness was carried out and the relationship between fracture energy of single-mode crack and energy release was obtained.In use of numerical simulation,the fracture energy of concretes mixed type crack was acquired.Based on stress intensity factor fracture critical cureve of Type I,Type Ⅱ,Type III,two-dimensional compound(Ⅰ-Ⅱ,Ⅰ-Ⅲ,Ⅱ-Ⅲ)and the critical surface of three-dimensional compound(Ⅰ-Ⅱ-Ⅲ)(i.e.a series of complete K criterion),the energy release rate of mixed mode crack can be calculated by use of their fracture toughness.Furthermore,the fracture energy of mixed mode crack was gotten,critical curve and critical surface of fracture energy was drawn,so that a series of complete G criterion was established.