International Journal of Advanced Structural Engineering
This paper presents analytical and numerical models for semirigid timber frame with Lagscrewbolt (LSB) connections. A series of static and reverse cyclic experimental tests were carried out for different beam sizes (400, 500, and 600 mm depth) and column–base connections with different numbers of LSBs (4, 5, 8). For the beam–column connections, with increase in beam depth, moment resistance and stiffness values increased, and ductility factor reduced. For the column–base connection, with increase in the number of LSBs, the strength, stiffness, and ductility values increased. A material model available in OpenSees, Pinching4 hysteretic model, was calibrated for all connection test results. Finally, analytical model of the portal frame was developed and compared with the experimental test results. Overall, there was good agreement with the experimental test results, and the Pinching4 hysteretic model can readily be used for full-scale structural model.
Moment resisting joint with lagscrewbolts shows good mechanical performance and aesthetic. However, beam and column joints rarely showed a brittle shear failure in a panel zone of a column in previous studies. Therefore, a joint system reinforced by long screws was developed to prevent from the failure in this research. The maximum shear strength of the joint increased with increasing the number of long screws. However, the average of six screws specimens was lower than that of four screws, because the glulam and some of the screws were damaged due to the narrow space between the screws during an inserting process of the screws.