STUDY OF IMPACT MECHANICAL RESPONSE AND STATISTICAL DAMAGE CONSTITUTIVE MODEL OF CERAMIC FIBER REINFORCED CONCRETE
A 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus is used to study the dynamic mechanical properties of ceramic fiber reinforced concrete(CRFRC) experimentally.The validity of the test has been approved.The statistical damage constitutive model of CRFRC under uniaxial impact compressive load is established based on an improved parallel bar system model(IPBS) to simulate the dynamic damage process.The results show that ceramic fibers can enhance the strength and the toughness of plain concrete remarkably,especially when the specimens are loaded in a high strain rate.The stress equilibrium and the constant strain rate are satisfied during the test by means of pulse shaping technique.The stress-strain curves derived from the constitutive model are consistent with the test results,and enable to predict the stress-strain relationship of CRFRC accurately before its damage.