Seismic Performance of Joint between Timber–Concrete Composite Beams and Steel Column with Innovative Semirigid Connections: Experimental and Numerical Studies under Quasi-Static Cyclic Loading Conditions

Abstract

In this study, an interior joint between timber-concrete composite (TCC) beams and steel column was as tested under quasistatic cyclic loads. To obtain an acceptable seismic performance, a type of innovative semirigid beam-to-column connection with screwed-in threaded rods (STRs) and novel steel links was designed for the joint. For validation, the detailed three-dimensional finite element (FE) models considering the elastic-plastic damage behavior of the materials were established in ABAQUS version 6.14. The test results demonstrated that owing to the excellent energy dissipation capacity of the steel links, the joints showed good seismic performance with plump hysteretic curves. Also, the stiffness and load-carrying capacity of the joint composite with concrete slab were higher than those of the joint with bare timber beams. However, because the yielding and deformation capacity of the beam-to-column connections were primarily derived from the steel links, the presence of a concrete slab had limited improvement on the energy dissipation capacity of the joints. Additionally, the FE model could clearly present the failure modes of the TCC joint, including the fracture of steel components, cracking of concrete, and withdrawal slip of threaded rods. The FE numerical results also showed good agreement with the test results in terms of the hysteretic curves, energy dissipation capacity, and stiffness degradation behavior.