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该文将起裂断裂韧度作为裂缝扩展的判定依据,应用ANSYS软件,对全级配混凝土Ⅰ型裂缝扩展过程进行数值模拟,分别计算了混凝土楔入劈拉试件的荷载-裂缝口张开位移曲线、临界裂缝长度和双K断裂韧度,并与溪洛渡大坝的断裂试验结果进行比较,吻合良好。同时,结合试验数据,将该文计算结果与《水工混凝土断裂试验规程》规定的标准尺寸试件断裂参数计算结果进行对比。结果表明:规程规定的方法也适用于大尺寸非标准试件双K断裂参数的计算,其误差率在5%以内。此外,对于全级配混凝土,只要通过试验测得其弹性模量、抗拉强度、抗压强度和起裂荷载,即可用该文提出的方法计算混凝土的双K断裂韧度和裂缝扩展全过程。应用该方法还可以得到全级配混凝土的KR阻力曲线。
In this paper, the fracture initiation toughness is taken as the criterion for fracture propagation. ANSYS software is used to simulate the type I crack propagation in the fully-graded concrete. The load-crack opening of the concrete wedged splitting tensile specimen is calculated separately Displacement curve, critical crack length and double K fracture toughness, and compared with the fracture test results of Xiluodu Dam, which are in good agreement. At the same time, the calculation results of the paper are compared with the calculation results of the fracture parameters of the standard-size specimens stipulated in the Rules for the Fracture of Hydraulic Concrete. The results show that the method prescribed by the rules is also applicable to the calculation of double K fracture parameters of large-size non-standard specimens with the error rate less than 5%. In addition, for the whole graded concrete, as long as its modulus of elasticity, tensile strength, compressive strength and initiation load can be measured experimentally, the method proposed in this paper can be used to calculate the double K fracture toughness and the whole process of crack propagation . The KR resistance curve of full grade concrete can also be obtained by this method.