摘要
该文研究了超高韧性水泥基复合材料的断裂性能评价准则。对纤维体积掺量为1.5%、2.0%与2.5%的超高韧性水泥基复合材料试件进行了弯曲断裂试验,基于非线性断裂力学,应用双J参数评价其断裂性能,并分析了其JR阻力曲线。结果表明,该材料的弯曲断裂表现出延性特征。应用双J参数评价该材料的断裂性能,当流入裂缝塑性区的能量大于起裂断裂能JIC时,裂缝出现;随后,裂缝稳定扩展;当流入塑性区能量大于失效断裂能JIF时,局部裂缝出现,材料进入失稳发展阶段。该材料的JR阻力曲线存在三阶段线性关系,分别以宏观裂缝出现点与主裂缝局部化点为分界点。在UHTCC的变形稳态发展阶段,相同面积的裂纹发展量消耗的能量相同。
A three-point fracture test was taken out on single notched beams of ultra-high toughness cementitious composites （UHTCC）, with three fiber volume fractions of 1.5%, 2.0% and 2.5%, in order to investigate the fracture property of this material. Ductile fracture exhibits for this material. On the basis of nonlinear fracture mechanics, the double-J criterion, that is the starting point of ductile stage, Jlc, and the starting point of failure stage, JIF, is applied to estimate the fracture toughness of UHTCC. When J〈 J/c, there is no macrocrack; J〉JIF, the failure crack is localized; and J1c〈J〈~Jle, the deformation develops stably. Based on the experimental results, the JR curve of UHTCC has three stages, with the dividing points of initial cracking and crack localizing. Furthermore, equal fracture energy is required for the equal quantity of crack growth.
出处
《工程力学》
EI
CSCD
北大核心
2013年第9期63-69,共7页
Engineering Mechanics
基金
中央高校基本科研业务费专项资金项目(BLX2012046)
国家自然科学基金重点项目(51008270)
关键词
结构工程
延性断裂评价准则
双J参数
超高韧性水泥基复合材料
JR阻力曲线
structural engineering
evaluation criterion for ductile fracture
double J-integral parameter
ultra-high toughness cementitious composites
JR curve
