Enhancement effect analysis of lattice-webs to GFRP-wood sandwich beams in flatwise and sidewise bending

This paper investigates the flexural behavior in flatwise and sidewise positions of novel generation composite sandwich beams with Paulownia and southern pine wood core and glass-fiber reinforced polymer (GFRP) facesheet and lattice-webs. A vacuum assisted resin infusion process (VARI) was employed to form sandwich beams with different numbers of webs. Two control wooden beams and eighteen lattice-web reinforced sandwich beams were subjected to four-point bending tests to determine their stiffness, capacity, and failure mechanisms in the flatwise and sidewise positions. The experimental results revealed that the composite sandwich beams failed in flatwise bending tests under lower load but produced a greater deflection compared to the beams in sidewise bending tests. With the increase in the number of lattice-webs, ductility was found to increase in flatwise positions while decreasing in sidewise positions. Analytical formulas for calculating the bending stiffness, capacity, and ductility of the GFRP-wood sandwich beams were provided, and the analysis results for mechanical performance showed good agreement with the experimental results.