Modeling of GFRP-reinforced concrete slabs under various impact masses and velocities

Abstract

Fiber-reinforced polymer (FRP) bar is increasingly employed, due to their advantages in higher tensile strength, light weight and corrosion resistance than steel bars. A numerical model was created and verified using existing testing data to explore the impact behavior of concrete slabs reinforced with Glass FRP (GFRP) under varied impact masses and velocities. The damage process was determined using calibrated model that depicted the failures of concrete slabs reinforced with GFRP bars when subjected to impact loading. Moreover, the influence of the impact velocity and impact mass on the impact behavior of the slabs was systematically examined. It is found that the characteristic of the time histories of central displacement and impact force has a certain functional relationship with impact velocity or impact mass. From the viewpoint of impact energy, the maximum central displacement grows linearly as impact energy increases, while the peak impact force and energy satisfy the quadratic function. In addition, as the impact velocity or mass increases, the response of the slabs transforms from global dominant to local dominant. Under the impact loads, the concrete dissipates most of the impact energy. Finally, both the normalized peak and residual displacements of the slabs vary in a practically linear form concerning the change of their natural frequency.