When a loading wave passes from one medium to another, one part of the wave is transmitted and the other part is reflected. The amplitude of these wave depends on the difference in an impedance between the two media, which is influenced by the material and geometrical properties. For the experimental determination of the concrete impedance long concrete cylinders were placed between the input and output bars of the split Hopkinson bar (SHB). The propagation of the waves were recorded by strain gauges applied directly to the concrete and the bars. Analytical relationships were used to draw conclusions about the elastic wave propagation velocity and the impedance of concrete. The modulus of elasticity was determined based on the propagation velocity of the longitudinal wave as well as from the stress equilibrium of the wave components at the interface between bar and concrete. In addition, a quasi-static modulus of elasticity was determined on concrete specimens with the same dimensions as the specimens that were used in the SHB. By comparing the statically and dynamically determined moduli of elasticity, it can be found out which one is more suitable for determing the dynamic stress-strain-relationship of concrete under compression.
|Title of host publication||Modern Developments in Performance of Structures under Extreme Loading - Proc. of PROTECT 2019|
|Publisher||Banthia, N.; Soleimani-Dashtaki, S.; Kodur, V.; Wu, B.; Fujikake, K.; Suresh, N.|
|Publication status||Published - 16 Sept 2019|