采用荷载-裂缝张开口位移曲线确定混凝土三点弯曲梁的断裂能  

Determination of fracture energy of three-point bending concrete beam using relationship between load and crack-mouth opening displacement

作　　者：张秀芳[1] 徐世烺[1] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《水利学报》2008年第6期714-719,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点项目(50438010);国家973项目(2002CB412709)

摘　　要：在采用荷载-裂缝口张开位移曲线确定断裂能思路的启发下,假设带缺口梁旋转点为等效虚拟裂缝的尖端点,根据旋转角和断裂功的概念,推导出了由三点弯曲梁试验测定的荷载-裂缝口张开位移曲线计算断裂能的计算公式,进行了不同高度的三点弯曲梁断裂试验,使用新公式计算了断裂能。结果表明,在试验范围内由荷载-裂缝口张开位移曲线计算的断裂能接近于采用RlLEM方法确定的断裂能,且变化较为稳定,可认为不存在尺寸效应。Based on the assumption that the rotation point of the notched three-point bending beam under loading is the tip of effective fictitious crack, a new formula for calculating the fracture energy of concrete according to the measured relationship between load and crack-mouth opening displacement （CMOD） of three-point bending beam is proposed. Fracture tests are carried out with different depths of beam. The fracture energy obtained from the proposed formula is approximately the same as that from the traditional RILEM formula.

关 键 词：裂缝口张开位移 断裂能 三点弯曲梁 旋转角 尺寸效应 

分 类 号：TV313[水利工程—水工结构工程]