多裂纹系在水工混凝土结构中的危害性评价

利用断裂力学的概念和方法,研究水工混凝土结构中多裂纹系应力强度因子的计算,根据“释放应力”的概念和修正ｃａｕｃｈｙ型奇异积分方程组,获得Ｆｒｅｄｈｏｌｍ积分方程组,并考虑裂纹之间,裂纹与边界间的相互作用的基础上,提出了虚拟荷载方法。最后,由所求得的应力强度因子和全场应力分析,判断出最危险裂纹扩展的位置,对带有多裂纹系的试样进行了实验,结果与计算值的吻合良好。

Evaluation of Harmfulness of Multiple Cracks in Concret Structures of Hydraulic Engineering

This paper dealt with the method of calculations for stress intensity factors caused by multiple-cracks in a concrete structure of hydraulic engineering. The concept and program of fracture mechanics was employed. According to the concept of "released stress" and modifying the Cauchy's singular integral equations, a Fredholm integral cquation system was obtained. Based on the consideration of interactions between the cracks and boundaries, the fictitious loading method was suggested. Finally, the S.I.F. and stress analysis could be finished. The judgement of the crack which was the most dangerous can also be solved. The cwperiments for the specimen with multiple-cracks were performed. The results showed good agreement with the calculation.