Flexural behavior of finger joint connected glulam wooden beams strengthened with CFRP strips

Abstract

Laminated wood beams have become a preferred solution compared to standard solid beams due to their ability to carry larger loads and in larger spans (greater distances). The increase in wood usage and the varieties of its applications have highlighted the necessity for the enhancement of the maximum load-carrying capacity and overall load-displacement behavior of laminated wood beams. Among the various strengthening options applied to increase the maximum load-carrying capacity and material performance, the most commonly preferred choice is strengthening with CFRP (Carbon Fiber Reinforced Polymer). Within the scope of this study, a total of 26 glulam wooden beam test specimens were produced. Variations were introduced in terms of the number of laminated layers, the distance between finger joint connection points, finger joint orientation, the use or lack of use of strenghthening, and distance between CFRP strips. The specimens were subjected to monotonic static loading through a four-point bending test, allowing for an examination of how these variables influenced the bending behavior. The values obtained from the experimental study and the numerical study conducted using the finite element software ABAQUS were compared and interpreted. These values included ultimate load capacity, displacement at ultimate load, initial stiffness, displacement ductility, and energy dissipation capacity. Based on the conducted analyses, it was observed that the strengthening method involving CFRP strips developed within the extent of this study significantly increased the load-bearing capacity of finger jointed glulam wooden beams. Furthermore, it was shown to have a highly positive impact on the overall load-displacement behavior.