Dynamic crack propagation of granite subjected to biaxial confining pressure and blast loading
AUTOR(ES)
He, Chenglong, Yang, Jun
FONTE
Lat. Am. j. solids struct.
DATA DE PUBLICAÇÃO
02/07/2018
RESUMO
Abstract To great understanding the dynamic crack propagation of rock under in-situ stress and blasting, the static-dynamic loading experimental platform was built. With different confining pressure (0MPa, 2MPa, 4MPa, 6MPa, 8MPa) and different ratios (K) of horizontal-to-vertical pressure (0, 0.25, 0.5, 0.75, 1), nine texts have been carried out in quadrate granite samples. The dynamic strain gauges and high-speed (HS) camera were used to measure strain field and observe crack growth. According to experimental results, the centrosymmetric damage zone is generated around borehole when K=1, the circumference compressive stress is formed by confining pressure, and it reduces the circumference tensile failure by blast loading. The number and size of the broken radius significantly reduce with confining pressure increases. As K decrease from 1 to 0, the tensile stress concentration is obviously around borehole in the vertical direction, and radial cracks grow from the stress concentration zone and develop into boundary under tensile stress wave from blast loading. From the numerical analysis based on Johnson-Holmquist in AUTODYN, crack branching appear near free boundary obviously, meanwhile the radial cracks grow and run through sample by reflected wave at last. Compared to the experimental results, the evolution and final shape of cracks are agree with the experimental results, the central damage area is less than latter because JWL equation neglect the gas loading in numerical calculation.
Documentos Relacionados
- Laboratory study of dynamic mechanical characteristic of granite subjected to confining pressure and cyclic blast loading
- Crack propagation under variable amplitude loading
- A numerical simulation of metallic cylindrical sandwich shells subjected to air blast loading
- A study on the response of single and double circular plates subjected to localised blast loading
- Numerical dynamic analysis of stiffened plates under blast loading