Seismic performance of an innovative cold-formed thin-walled steel–timber composite beam-column joint

Fast-growing timber has a short growth cycle, wide distribution, and abundant reserves, making it suitable for extensive application in building structures. However, due to its low strength, numerous defects, and high dispersion, it is not suitable for direct use as a structural material. Based on the ideology of improving the mechanical properties of fast-growing timber using cold-formed thin-walled steel, this paper proposes an innovative cold-formed thin-walled steel–fast-growing timber composite beam-column joint. Pseudo-static tests are conducted on 6 joints to study their failure modes, stiffness degradation, strength degradation, ductility and energy dissipation. The results show that the addition of stiffener rib to the joint can increase the positive and negative load-bearing capacities of the joint by 65.06 % and 94.04 %, respectively. The hysteretic response analysis and parametric analysis of the joints are conducted using ABAQUS finite element software. The results indicate that increasing the length of the stiffener rib, the diameter of the screws, and the thickness of the L-shaped steel are effective measures to enhance the seismic performance of the joints. The simplified spring unit model of the joint is established using the component method to calculate the initial rotational stiffness of the joint. Based on different failure modes of the joints, the calculation method for the flexural bearing capacity of the joints is established. The theoretical results can reflect the mechanical performance of the joints, providing a reliable design basis and reference for the design and application of the joints.