Hits:

Indexed by:会议论文

Date of Publication:2011-01-07

Included Journals:EI、CPCI-S、Scopus

Volume:163-167

Page Number:908-912

Key Words:Concrete; Mode I-II; Crack propagation; Fracture mechanics; FEM

Abstract:The crack criterion is important to determine the crack propagation for mode I- II fracture in concrete. The paper aims to obtain the initial crack criterion of four-point shearing beams experimentally, which can be applied in the numerical simulation for crack propagation process. A series of experiments of four-point shearing notched beams of concrete with five different heights of 80mm, 100mm, 120mm, 140mm and 160mm respectively were carried out to measure the initial loading P(ini). The different combinations of K(I)(ini) and K(II)(ini) corresponding to P(ini) were obtained according to different positions of pre-cracks in the specimens, and the initial crack criterion was fitted using the combinations of K(I)(ini) and K(II)(ini). With the assumption that the crack will extend when the difference between the stress intensity factor at the crack tip caused by the load P and the one caused by the cohesive force attained the above K(I)(ini) - K(II)(ini) curve, the criterion was applied to simulate the crack propagation process in the paper. It was found that the numerical analysis showed a good agreement with the experimental results and that the size effect is not remarkable for the K(I)(ini) -K(II)(ini) curves of different heights specimens in the test.