Bracing FRP I-section beams to avoid lateral-torsional buckling

This article explains as to how lateral-torsional buckling can be avoided in fiber-reinforced plastic (FRP) beams having an I-shaped cross section and subjected to major-axis bending. To enable a FRP beam to be able to develop its maximum bending moment capacity corresponding to material cracking of the extreme fibers, a number of lateral braces need to be provided. Herein, a procedure is outlined for determining the required number of lateral braces for a FRP I-section beam. It is shown that a FRP beam loaded about its major cross-sectional axis can experience a drastic reduction in its bending moment capacity if such lateral bracing is not provided, whereas it can develop its maximum load-carrying capacity up to the cracking of the extreme fibers if a sufficient number of lateral braces are provided.