Behaviour of structural glulam beams from sustainable fibre composite sandwich panels

This paper presents the results of experimental investigation into the flexural and shear behaviour of glue-laminated (glulam) fibre composite sandwich beams with a view of using this material for structural applications. The building block of these structural beams is a new generation composite sandwich structure made up of glass fibre reinforced polymer skins and high strength core material. In the experimental investigation, beams with 1, 2, 3, and 4 composite sandwich panels glued together were subjected to 4-point static bending and asymmetrical beam shear tests in the flatwise and in the edgewise positions. The results of the flexural test showed that the glulam sandwich beams in the edgewise position failed with higher strength but have slightly lower bending stiffness than beams in the flatwise position. The results however indicated that the bending stiffness of the flatwise specimens converges to that of the edgewise specimens with increasing laminations. More importantly, the specimens in the edgewise position failed with greater ductility due to the progressive failure of the fibre composite skins while the specimens in the flatwise position failed in a brittle manner due to debonding between the skin and core. Under shear loading, the behaviour of the sandwich beams is significantly influenced by the shear strength and modulus of the fibre composite skin. It has been demonstrated that the glue-laminated sandwich beams exhibited better performance than the individual sandwich beams. The results of the study suggest the high possibility of using composite sandwich construction in the development of structural laminated beams