Study of joints in wooden structures with glue and screw connections for stiffening diaphragms and disks in multi-story buildings

Introduction. The stiffness of prefabricated disks and diaphragms is considered a key parameter in designing multi-story buildings with wooden frames. Under the action of horizontal wind and seismic loads, the stiffness of wooden structures and their connections affects the distribution of forces among the structural elements and floors of the building. The stiffness and ductility of the joints in disks and diaphragms determine the dynamic characteristics of the building frame, such as the structural logarithmic decrement and damping ratio. The stiffness of vertical and horizontal joints influences the natural frequencies of multi-story buildings, while ductility affects the efficiency of energy dissipation during seismic events. Aim. To investigate the load-bearing capacity, stiffness, and ductility of joints with glue and screw connections for horizontal and vertical joints in stiffening diaphragms and disks in multi-story wooden buildings. Materials and methods. Following the methodologies outlined in State Standard 33082-2014, a comprehensive experimental study was conducted to assess the strength and deformation characteristics of connections using glued and screwed rods and joints based on them for inter-slab and inter-panel joints in stiffening diaphragms and disks made from laminated wood structures. Results. The load-bearing capacity, stiffness coefficients, and ductility of glue and screw connections with varying depths of screw rod insertion and joint connections for wooden disks and diaphragms were determined under various loading types (shear, tension, and compression). Conclusions. The analysis showed that the developed joints for wooden structures with glue and screw connections meet the requirements for high stiffness and can be utilized for joints in floor disks and wall diaphragms of multi-story wooden buildings. The obtained values of ductility coefficients for the tested joint connections indicate their capability to effectively dissipate energy during seismic impacts on the structure.