摘要
将线弹性断裂理论与虚拟裂缝模型相结合 ,利用楔入劈拉试件在实验中测得的最大荷载Pmax及对应的裂缝口张开位移 umc、断裂能 Gf等参数得到了混凝土裂缝亚临界扩展量Δac的解析解 ,据此计算了尺寸为 4 50 mm× 4 50 mm× 4 50 mm 4组不同骨料最大粒径混凝土试件的起裂断裂韧度 Kini Ic、失稳断裂韧度 Kun Ic(即双 K断裂参数 )及临界裂缝尖端张开位移 utc.结果表明 ,Kini Ic、Kun Ic 随骨料最大粒径 Dmax 的变化而变化 .当 Dmax ≤ 4 0 mm时 ,Kini Ic、Kun Ic 随 Dmax 的增大而增大 ;当 Dmax >4 0 mm时 ,Kini Ic、Kun Ic 随 Dmax 的增大而减小 ,而 utc 则与 Dmax 无关 .
Based on the linear elastic fracture mechanics combined with the fictitious crack model, the precritical crack propagation length Δa c of concrete was analytically evaluated by using the maximum load P max , critical crack mouth opening displacement u mc and fracture energy, et al. measured in experiment by means of wedge splitting specimen. According to the analytical solution of Δa c, the initiation fracture toughness K ini Ic , unstable fracture toughness K un Ic (double K fracture parameter) and critical crack tip opening displacement u tc were analytically determined, in which the specimen size is 450 mm×450 mm×450 mm with four series of different aggregate sizes. Results show that the double K fracture parameters K ini Ic and K un Ic vary with D max . When D max is less than or equal to 40 mm, K ini Ic and K un Ic increase with the increase of D max , and when D max is larger than 40 mm, K ini Ic and K un Ic decrease with the increase of D max , but the u tc value is independent of D max of concrete.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2000年第3期358-361,共4页
Journal of Dalian University of Technology
基金
国家杰出青年科学基金资助项目!( 5 962 5 814 )
辽宁省自然科学基金资助项目!( 9810 80 0 1)
