Experimental study and theoretical analysis on mechanical properties of mortise-tenon joints in composite frames

Abstract

In order to explore the feasibility to develop tenon-and-mortise joints in steel-concrete composite structures, a novel type of steel-concrete composite assembly joints, i.e., tenon-mortise joint composite frame joints was proposed. Two full-scale tenon-mortise joint node were designed and manufactured. The monotonic static loading test at the beam end was carried out, and the finite element simulation analysis was carried out using ABAQUS software, and the influence of steel bar amount in the beam on the failure mode, bearing capacity, stiffness, bending moment-rotation angle relationship was discussed. The test results show that the joint has good load-bearing capacity and ductility. The increase in the steel bar amount in the beam improves the stiffness and positive moment bearing capacity of the joint to a certain extent, but has little effect on the negative moment bearing capacity. The failure modes of joints are mainly bulge deformation of column wall and tensile fracture of composite beam flange floor slab. The finite element simulation results are in good agreement with the experimental results, which verifies the validity of the finite element model. Finally, the shear mechanism of this type of joint was analyzed, and the results show that the shear bearing capacity of the core area of the joint is mainly provided by steel pipes, channel steel webs and concrete oblique bars in the core area. The superposition method was used to deduce the shear bearing capacity formular of this type of joint. The proposed formula can provide reference for the design of this type of joint.