The fracture process zone associated impacted, three-point bend (TPB), precrack was analyzed by a hybrid finite element analysis. The crack "'"""J.J.""' ... dynamic mode I resistance, K1dyn, sliding resistance was undetectable resistance increased under this mixed .... , .. '",,.,…
The fracture process zone associated impacted, three-point bend (TPB), precrack was analyzed by a hybrid finite element analysis. The crack "'"""J.J.""' ... dynamic mode I resistance, K1dyn, sliding resistance was undetectable resistance increased under this mixed .... , .. '",,., 1 The fracture process zone (FPZ), as an "zone in which the material undergoes strain-softening 11 is the strip yield or cohesive force zone ductile fracture 6, 1985) designated -cohesive Hillerborg et al ( 197 concrete as the fictitious crack where opens upon reaching the tensile fracture energy, exceeds a 179 relates crack closing stress (CCS) versus crack opening displacement (COD) the FPZ, has been modeled theoretically by Horii et al (1989) and Bazant (1987) and experimentally by Du et al (1990). Theoretically the fictitious crack model requires only a single parameter ft for stable crack growth the crack tip of a traction free crack. In practice, however, this crack tip cannot advance without the extension of the FPZ crack and thus requires an additional critical GJ for crack propagation. The two-parameter fracture criterion of Jenq et al (1985, 1987), which FPZ by a critical crack tip opening displacement, dt, is appealing since it retains linear elastic fracture mechanics aspect of concrete fracture through a critical stress intensity, factor, KJC. This criterion has been extended to mixed Modes I and II fracture of concrete replacing the Mode I stress intensity factor, with an effective stress intensity factor, Kr2 = [KI2 + Kn2] 1/2 and the vector sum of the opening and sliding crack tip displacements . FPZ model with a crack tip singularity (Yon et al, 1990), referred to as S-FPZ model, utilizes the FPZ of the fictitious crack model without the sharp rise in the CCS near the crack tip and a crack tip stress intensity factor similar to (Jenq et al, 1985).