【摘要】 断裂能G_r是一个基于虚拟裂缝模型(FCM)并考虑了混凝土软化特性的断裂参数,此参数在混凝土结构的非线性开裂计算中是必不可少的。RILEM推荐采用三点弯曲梁作为测定G_r的试件,标准试件的断面尺寸为100mm×100mm,但也可采用更大尺寸的试件。因而,G_r的尺寸效应问题就必需研究。据此,作者进行了100mm×100mm×400mm,400mm×200mm×1600mm和800mm×400mm×3200mm三种尺寸的混凝土三点弯曲梁G_r的系列测试,发现G_r具有显著的尺寸效应。这一结论对大型混凝土结构的开裂分析有着重要的价值。本文就影响G_r尺寸效应的一些主要因素进行了分析和讨论。更多还原

【Abstract】 Fracture engrgy G,is a fracture property parameter which is based on the Fictitious Crack Model(FCM)and can well reflect the strain softening of concrete.It is necessary for the nonlinear cracking calculation of concrete.The three-point bending beam is recommended by RILEM to testing fracture energy of concrete.For the standard specimen,the size of cross section is 100mm×100mm, but larger ones can also be used.Therefore,the size effect on G_F needs to be studied.Three specimens of 100mm×100mm×400mm,400mm×200mm×1600mm and 800mm×400mm×3200mm were tested by the authors.The result is of important value for cracking analysis of large concrete struc- tures.In this paper,the influence of some main factors on the size effect is also discussed and ana- lyzed.更多还原