As a composite material, glulam can enhance the mechanical properties of wood beams. In order to obtain glued laminations of any length, the wooden beams are connected in the form of finger joints. The finger joint structure can remove the knot defects and extend the short members into long members. These advantages make finger joint wood a common engineering component in the wood industry. Nowadays, the analysis of finger-joined materials is mostly based on bamboo, and the main researches mostly focus on the processing technology and parameter optimization, and there is little analysis of the damage form. Based on this paper, the following aspects are mainly studied.
Through the comparison of mechanical properties of finger-joined wooden beams and solid wood beams strengthened by CFRP, the displacement load curves of solid wood beams, the displacement load curves of finger-jointed wooden beams, the displacement load curves of solid wood beams and the displacement load curves of finger-joined wooden beams were obtained The relevant damage types were classified and shown a corresponding distinction between the various types of damage characteristics. CFRP improved the reinforcement strength of finger jointed wooden beams by 70% and the impact on solid wood beams by 22% in this paper. The results showed that the reinforcement strength of CFRP on finger jointed wooden beams due to the slip effect of CFRP-restricted finger joints, and the original crack propagation was changed due to the presence of damaged structures inside the material.
Through the analysis of the reinforcement values and experimental data of different components, the corresponding displacement load curve, stress-strain relationship curve and flat section assumption relationship diagram are obtained. Due to the large dispersion of wood, the experimental data results are not completely consistent with the numerical analysis, which is related to the real complex structural heterogeneity inside the wood. The most important influencing factors are damage and knots.
The finite element analysis of finger joints was carried out by ABAQUS software. The finger jointed wood and CFRP simplified model were established. The analysis theory was combined with the experimental results and numerical simulation. By using XFEM model, the relevant node deformation map was obtained. The corresponding wood components were calculated and analyzed. Ultimate bearing capacity distinguishes different forms of damage. By analyzing the damage form of the interface, reasonable suggestions were given. Considering the mechanical relationship of the damage relationship on the finger-joined wooden beams strengthened by carbon fiber cloth, the damage structure was researched, and the influence of the reinforcement on the internal force of the section was under consideration.