Novel Ductile Moment-Resisting Frame Compound of Steel Gusset Plate for Beam-to-Column Connections and I-Shaped FRP Profile Sections

Moment-resisting frames (MRFs) are characterized by high energy dissipation capacity relying on plastic hinge formation at the two ends of beams. Despite their numerous advantages, Fiber-Reinforced Polymer (FRP) profile sections used in MRF systems suffer from low ductility, which remains a dilemma. FRP profiles have emerged as a novel and valuable material with significant advancement in structural engineering. In this paper, an MRF system composed of novel gusset plate steel connections (to provide ductility) and FRP profile sections for beams and columns is proposed and investigated numerically and parametrically. The results indicate that up to a rotation of 0.04 rad, the proposed gusset plate dissipates energy, whereas the beam and columns remain essentially elastic. Accordingly, with an increase in the ratio of vertical length to thickness of the gusset plate, energy dissipation is reduced. Through an increase in the ratio of horizontal length to thickness of the gusset plate from 63.5 to 127 and 254, the ultimate strength of the connection is reduced by 4% to 10% and 3% to 7%, respectively. It is suggested that gusset plate thickness be selected in such a way that its slenderness is not less than 47. Subsequently, the required equation is proposed to achieve the optimum performance of the system.