ABSTRACT:

Dynamic uniaxial compressive strength of Pennsylvania blue sandstone was investigated using split Hopkinson pressure bar both physically and numerically. A hybrid finite-discrete element code called CA3 was employed to simulate the physical tests. The incident and transmitted bars were modeled using finite elements while the rock specimen was represented by a bonded particle discrete system. The incident stress pulse measured in the physical test was utilized as the input for the numerical simulation and was applied to the free end of the incident bar. Analysis of the numerical results suggests an underestimation of the dynamic rock strength; the effect of axial and circumferential inertia of the specimen didn’t manifest the strength value consistent with the physical observation. Therefore, a parameter called rock strength enhancement coefficient was introduced which increases the bond strength between the particles as a function of the relative velocity of particles at the contact points. A much better match between the physical and numerical results is observed if this coefficient is applied in the numerical simulation.

This content is only available via PDF.
You can access this article if you purchase or spend a download.