Behavior and modeling of shear-critical RC beams under impact loading

Abstract

The lack of a complete understanding of shear behavior under high dynamic conditions hindered the efforts for accurate prediction of impact behavior, since severe shear mechanisms may dominate the behavior of RC structures when subjected to impact loads. This current study involves a well-instrumented experimental program that was undertaken to contribute to our understanding of the effects of shear mechanisms on the behavior of reinforced concrete (RC) structures under impact loads. The test results showed that the shear characteristics of the RC beam specimens played an important role in their overall behavior. All specimens, regardless of their shear capacity, developed severe diagonal shear cracks, forming a shear-plug under the impact point. Furthermore, the application of the Disturbed Stress Field Model (DSFM) as an advanced method of modeling shear behavior under impact conditions is also investigated. A two-dimensional nonlinear finite element reinforced concrete analysis program (VecTor2), developed previously for static loads, was modified to include the consideration of dynamic loads such as impacts. VecTor2 analyses of the test specimens were satisfactory in predicting damage levels, and maximum and residual displacements. The methodology employed by VecTor2, based on the DSFM, proved to be successful in predicting the shear-dominant behavior of the specimens under impact.