Bonded Sleeve Connections for Joining Tubular Glass Fiber–Reinforced Polymer Beams and Columns: Experimental and Numerical Studies

Abstract

A bonded sleeve connection was developed for joining tubular glass fiber–reinforced polymer (GFRP) beams and columns. It utilizes a sleeve connector made by welding a steel tube to a steel endplate. The steel tube is then inserted into and adhesively bonded with the GFRP beam end and the endplate is connected to the GFRP column using through-bolts. Four beam-to-column specimens with different bond lengths between the GFRP beam and steel tube and different numbers of bolts were tested. The moment-rotation responses, failure modes, and local strain responses were experimentally received and comparatively studied. The measured initial rotational stiffness of the proposed bonded sleeve connections was evaluated against a standard classification and compared to existing connection systems. Numerical analysis was also performed through finite element (FE) modeling. Paired contact elements and pretension elements were used to model the bolted connections, taking into account effects of friction, pretension force, and bolt hole clearance. Relevant failure criteria were also used to indicate yielding of the steel endplate and cohesive failure. Modeling and experimental results compared well in terms of moment-rotation behavior and failure modes. Further parametric study evidenced dominant effects of endplate thickness on the initial rotational stiffness of the connections.