Static and dynamic behavior of concrete and granite in tension with damage

A series of dynamic and static tensile-splitting experiments were performed on concrete and granite specimens to investigate the effect of induced dam age on their tensile strength. These experiments were performed as part of a larger effort investigating the penetration process into the two material s. The strain rate each specimen was subjected to remained constant for the se experiments, while the level of induced damage was increased. Damage was induced into the specimens through repeated drop-weight impacts and quanti fied using a statistical technique. The dynamic splitting experiments were performed using a split Hopkinson pressure bar (SHPB), while the static spl itting experiments were conducted per the ASTM standard procedures D3967 an d C496. As part of the investigation, photoelastic dynamic tensile-splittin g experiments were also performed to establish the validity of using static relations for the determination of dynamic tensile strength. The experimen ts showed that the static splitting strength was highly dependent on the or ientation of the induced damage with regard to the applied loading; however the dynamic tensile strength decreased with increasing damage with no appa rent dependency on the random damage orientation. Photoelastic experiments have shown that the mechanism of failure changes for the dynamically tested damaged specimens, reducing their dependence on damage orientation. (C) 20 01 Elsevier Science Ltd. All rights reserved.