NUMERICAL-ANALYSIS OF HIGH-STRAIN RATE SPLITTING-TENSILE TESTS

Experimental splitting-tension tests were conducted on 2-in. diameter concrete specimens in a Split Hopkinson Pressure Bar at strain rates o f 4.4, 10.6, and 14.7/sec. The specimens were instrumented with electr ical resistance strain gages and break circuits to detect crack initia tion and growth. Experimental results indicate that there is a shift o f crack initiation time relative to the peak stress. Also, experimenta l strength vs strain rate data reveal that the dynamic tensile strengt h of concrete is significantly higher than the static tensile strength . A comprehensive numerical analysis was conducted on the splitting-te nsile experiments to investigate the effects of varying the uniaxial t ensile strength of the concrete on the crack initiation time, stress s tate, crack growth characteristics, and failure mode in the concrete s pecimens. The results of the numerical analyses are used to enhance th e understanding of concrete tensile strength strain rate sensitivity.