碾压混凝土坝诱导缝端应力强度因子计算研究

Analysis of Stress Intensity Factor in Crack Director Transection of RCC Dams

针对碾压混凝土坝双向间隔诱导缝,提出了更加符合实际的Ⅰ型断裂矩形简化分析模型,与一般的椭圆形简化分析模型进行了对比分析。分别采用基于位移法和J积分的应力强度因子三维有限元计算方法,得到诱导缝断面裂纹尖端的应力强度因子。通过对有限元计算结果分析,论述了两种简化分析模型各自特点及适用性;并且对影响诱导缝应力强度因子的因素进行研究,得出双向间隔诱导缝应力强度因子的回归计算公式。其结论对双向间隔诱导缝断裂设计具有一定的参考价值,同时也为诱导缝断裂性能试验研究提供一定的参照依据。

For contrasting with ellipse predigestion analysis model, rectangle predigestion analysis model is put forward; it accords with actual two direction interval crack director of rolled compacted concrete dams much more. Stress intensity factors of crack tip in the crack director transect are separatly calculated by three-dimensional finite element method based on displacement method and J integral. By analysis FEM results, characteristics and applicability of the two kinds of predigestion analysis model are discussed;influencing factors of stress intensity factors in the crack director are investigated;and a regression formula of the two direction interval crack director is educed. The conclusions have some reference values for fracture design of the crack director;and provide some consulting grounds for fracture capability test of the crack director.