Local Buckling and Failure of Pultruded Fiber-Reinforced Plastic Beams

An experimental investigation of the local compression flange buckling and failure of commercially produced pultruded fiber-reinforced plastic (FRP) I-shaped beams is described in this paper. Results of tests on pultruded E-glass/polyester and E-glass/vinylester composite material beams are described. The test configuration was designed to cause local buckling and ultimate failure of the compression flange of the beams and to prevent global lateral-torsional buckling. The beams were stiffened to prevent crippling and warping at the supports, and local tensile failure at the load points. All beams were monitored with strain gages and LVDT’s. Buckling loads, failure loads, buckling stresses, deflections, and failure modes are reported. Effective mechanical properties of the beams, obtained from overall flexural and shear strain data, are presented. A discussion of the different failure characteristics of the polyester and the vinylester beams is provided.