Bending performance of GFRP-wood sandwich beams with lattice-web reinforcement in flatwise and sidewise directions

This paper investigates the flexural behaviors of novel composite sandwich beams that feature Paulownia or Southern pine wood core and glass fiber reinforced polymer (GFRP) face-skins reinforced with lattice-webs. A vacuum-assisted resin infusion process was employed to mold sandwich beams with different numbers of webs. Two control wooden beams and eighteen lattice-web reinforced sandwich beams were subjected to four-point bending to determine their stiffness, load capacity, and failure mechanisms in the flatwise and sidewise directions. The experimental results revealed that the composite sandwich beams in flatwise bending tests failed under a lower load but yielded a larger deflection than those in sidewise bending tests. With an increase in the number of lattice-webs, pseudo-ductility was found to increase in the flatwise directions but decrease in the sidewise directions. Analytical equations were developed for calculating the bending stiffness, load capacity, and pseudo-ductility of the GFRP-wood sandwich beams, and the corresponding analytic results were found in good agreement with the experimental results.