Abstract:Changes of the material fracture energy consumption with crack propagation can be described by a crack extension resistance curve, one of the fundamental fracture criteria in crack mechanics. Recently, experimental observation of the fracture behavior in concrete was used to develop a new fracture criterion, the crack extension GR resistance curve, to analyze crack propagation during the entire concrete fracture process. The variation of the crack extension resistance is mainly associated with the energy consumption in the fracture process zone ahead of the stress-free crack tip. The crack extension resistance is then a function of the softening curve, which is a basic mechanical property in the fracture process zone. The relationship between the softening curve and the crack extension GR resistance curve is then analyzed based on results of three-point bending beams tests. The results indicate that the characteristic points of the crack extension resistance GR curve is closely related to the characteristic point on used tension softening curve.
Xu Shilang, Zhang Xiufang. The new GR crack extension resistance asa fracture criterion for complete crack propagation in concrete structures. China Civil Engineering Journal, 2006, 39 (4): 19―28 (in Chinese)
Zhang Xiufang. New GR crackextension resistance and energy transformation analysis during thewhole fracture process in concrete. Dalian: Dalian University of Technology, 2007 (in Chinese)
Hillerborg A. Aanalysis of crack formation and crack growth in concrete by meansof fracture mechanics and finite elements. Cement and Concrete Research, 1976, 6(6): 773―782 doi: 10.1016/0008-8846(76)90007-7
Xu S L, Reinhardt H W. Determination of double-K criterion for crack propagation in quasi-brittlefracture. Part II: Analytical evaluatingand practical measuring methods for three-point bending notched beams.International Journal of Fracture, 1999, 98(2): 151―177 doi: 10.1023/A:1018740728458
Reinhardt H W, Xu S L. Crack extension resistancebased on cohesive force in concrete. EngineeringFracture Mechanics, 1999, 64(5): 563―587 doi: 10.1016/S0013-7944(99)00080-6
Tada H, Irwin G R. Stress Analysis of CrackHandbook. Hellertown, USA: Del Research Corporation, 1972
Reinhardt H W, Cornelissen H A W, Hordijk D A. Tensile tests and failure analysis of concrete. Journal of Structural Engineering, 1986, 112(11): 2462―2477 doi: 10.1061/(ASCE)0733-9445(1986)112:11(2462)