Research on Shear Capacity of Concrete-Filled Square Steel Tubular Column to Unequal Height Steel Beam Joint with External Diaphragm

Abstract

In order to study the shear bearing capacity of joints with concrete-filled square steel tubular column and unequal height steel beam, 4 joints specimens were tested under low-reversed cyclic lateral loading. 17 models with different parameters were established by using OpenSees finite element software, and the nonlinear finite element analysis had been carried out. The failure models and shear strain changes of the specimens were observed. The results showed that the shear failure modes of joints can be divided into a small core panel zone mode and an entire panel zone mode. Based on the test and numerical simulation results, the simplified shear model of joints with unequal height steel beam is established, and the method for calculating the shear capacity of the joint is put forward, which is composed of the steel tube webs of the panel zone, the concrete of the panel zone, the steel tube flange of the panel zone and the external diaphragm. The calculation results are in good agreement with the experimental values and numerical simulation results. The calculation method can accurately evaluate the shear bearing capacity of this type of joints and can be used as a reference for the application of practical engineering.