Effect of Diameter and Number of Bolts on the Rotation Stiffness of Beam-to-Column Timber Joints

Beam-to-column joints affect the behavior of the building. This research aims to obtain an empirical equation of the rotational stiffness of the beam-to-column timber joints with variations in the number and diameter of bolts. The method used is the destructive method to obtain elastic and post-elastic history of load and deformation of timber joints. The scope of the research is the timber using red meranti (Shorea spp.) species, with a cross-sectional size of 50mm x 100mm, bolts using various diameters of 8, 10, and 12mm. Beam-to-column timber joints use a variety of one, two, and three bolts. Testing uses a monotonic loading type. The behaviors reviewed are load-carrying capacity and rotational stiffness. The results obtained from this research, which are the proposed bilinear moment-rotational stiffness relationship curve model for beam-to-column timber joints, can provide benefits in modeling and analyzing the structure of multi-storey wooden buildings, especially in modeling parameters of spring elements for beam-to-column joints of red meranti (Shorea spp.) timber. The proposed equation for moment capacity and rotational stiffness in terms of elastic range, namely My and θy, has an R2 of 0.86 and 0.87, respectively. These results indicate a strong relationship between moment capacity, bolt diameter size, and number of bolt variables in a statistical model. In the design context, the parameters used are at elastic limit range conditions. The results of the research show that the number of bolts has a significant effect on the beam-to-column joint, namely the non-linear moment and rotational capacity increases.