Numerical investigation on structural glass beams with GFRP-embedded rods, including effects of pre-stress

The bending performance of laminated glass (LG) beams with Glass-Fibre-Reinforced-Polymer (GFRP)-embedded rods is numerically assessed in this paper, based on earlier experimental investigations. Compared to existing literature efforts related to reinforced glass beams – typically including external steel or FRP tendons and/or reinforcement sections adhesively bonded to glass edges in tension – careful consideration is given to the still rather innovative concept of traditional LG beams that contain pultruded GFRP rods embedded within the interlayer foils. Taking advantage of past experimental results and preliminary Finite Element (FE) outcomes for hybrid glass beams, the quasi-static bending performance at room temperature of several geometrical configurations of LG beams with GFRP-embedded rods is compared. These geometrical configurations include variations in number, size and position of rods. The effects and possible benefits due to initial pre-stressing forces for the GFRP rods are also investigated. As shown for some selected configurations only, GFRP-embedded rods can provide active contribution to traditional LG beams, both in terms of post-cracked resistance and ductility. At the same time, given a reference geometry, a certain level of initial pre-stress can further exploit the potential of the same GFRP rods, acting as pre-tensioned tendons thereby enhancing the initial fracture strength. Several aspects should be properly taken into account to assess and optimize the overall performance of these systems, however, since both their elastic and post-cracked performance are highly sensitive to various mechanical and geometrical input parameters.