Influence Factors on the Load-Carrying Capacity of Bolted Timber Connections with Slotted-In Steel Plates

The load-carrying capacity of bolted timber connections with slotted-in steel plates is a critical guide for the practical design of timber buildings. This work investigates various factors that influence the load-carrying capacity of bolted timber connections through testing and gives a comparison of the calculated load-carrying capacity from different standards. A total of 72 bolted timber connections with a range of bolt diameters and wood thicknesses were investigated during pull-out tests. The test results indicated that these connections exhibited three typical failure modes. These different failure modes can be distinguished with the slenderness ratio. The obtained initial stiffness and peak force from the measured force-deformation curves are used to define regression equations, considering the factors of wood thickness and bolt diameter. Then, an analysis formula for the calculation of load-carrying capacity is derived by considering the failure mechanism. The load-carrying capacity calculated from the analysis formula agrees with the test data, demonstrating that the derived formula is reasonable. In addition, the load-carrying capacity calculated from the analysis formula is compared with those obtained from different standards. This work enhances the understanding of the failure mechanisms of bolted timber connections with slotted-in steel plates and the factors influencing their load-carrying capacity, providing guidance for practical design.