基于虚拟裂缝模型,提出一种计算混凝土三点弯曲梁等效断裂韧度的解析方法,并将虚拟裂缝面上黏聚力分布曲线简化为双线性。采用该方法,只要测得混凝土弹性模量Ee和抗折强度fr,就可以计算梁的极限荷载Pmax和临界等效裂缝长度ar进而求得等效断裂韧度K^sIC,而不需要进行断裂试验。
Based on fictitious crack model, an analytical solution to calculate the effective fracture toughness of standard three-point bending notched concrete beams is proposed.In the present study, the shape of softening curve in the fictitious crack is simplified to be bilinear.By using the proposed analytical solution ,when the elastic modulus Ecand the flexural tensile strength f of the beams are measured,the maximum applied load Pmax, the critical effective crack length a and the effective fracture toughness Kic can be predicted without any experiment.