The Experimental Research on the Flexural Behavior of Steel Plate Strengthened Pre-Stress Glue-Lumber Beams

In this paper, the experimental research was conducted on the flexural behavior of 18 steel plate strengthened pre-stress glue-lumber beams (the steel plate was fixed by glue or glue & screws), and compared it with ordinary steel plate strengthened glue-lumber beams (simplified as OB). The results showed that, compared with OB, when the 2mm or 3mm thick steel plate was glued, the bearing capacity was similar, while when 4mm thick was glued, there were no separation between glue-lumber and steel plate, and the bearing capacity improved by 19.5%; when the same thick steel plate was glued and fixed it by screws, its bearing capacity had no much difference, while the probability of out-of-plane stability increased. With the increase of steel plate thickness, the beam deformability increased, and compared with OB, the deflection decreased obviously, and the pre-stress had no influence on beam stiffness. The section strain of steel plate strengthened pre-stressed glue-lumber beam was accorded with plane section assumption, therefore, for this kind of member, on the basis of tensile and compressive failure mode, the bending capacity calculation formula was proposed, and compared it with experimental results, the average error between theoretical value and experimental value was no more than 10%.