Experimental Study on Composite Sandwich Beams with Longitudinal GFRP Webs

This study focused on the bending performance of sandwich beams composed of GFRP skins, PU foam core, and longitudinal GFRP webs. The longitudinal webs were distributed along the length direction of the beam. Six beams were tested to validate the effectiveness of longitudinal webs for increasing the ultimate bending strength. Compared to the control specimen, a maximum of an approximately 316% and 59% increase in the ultimate bending strength and bending stiffness can be achieved, respectively. The influences of longitudinal web thickness, fiber paly angle and web spacing on failure mode and bending stiffness were also investigated. Test results demonstrated that the ultimate bending strength and initial bending stiffness can be enhanced by increaseing the web thickness and reduce web space. Meanwhile, various failure modes were summarized, including core shear failure, skin compressive failures, and webs buckling failure, due to the presence of the longitudinal webs. (paper)