Nonlinear Numerical Analysis on Seismic Performance of New-type Outer Hoop Box Column Joints

Abstract

The connection between the upper and lower structure is the key to seismic design of RC frame-lightweight steel mixed structure. This paper proposes a new type of outer hoop box column joint for this kind of mixed structure, which aims to strengthen the connection between exiting and new building, reduce the stiffness mutation and facilitate construct. In order to study the seismic performance of the new type of joint, the ABAQUS finite element software was used to carry out the numerical analysis of the new type of joint under the action of low-cycle cyclic loading with a 1/2 scale model, and the factors that affect the seismic performance were discussed in-depth. The results show that the hoop effect of the outer hoop steel plate strengthens the restraint on the core area of the joint and its surrounding members, which causes the plastic hinge position of the concrete beam to move outward, effectively protects the core area of the joint, and is beneficial to the bearing capacity of the new joint. Appropriately increasing the axial compression ratio can increase the bearing capacity, initial stiffness and yield displacement of the new joints to a certain extent.