Research on Mechanical Mechanism of Circle Tubular Steel Column-I-Shaped Section Dual-Lintel Joints in Traditional Style Buildings

The dual-lintel-column joints in traditional style buildings have special construction， and their most obvious feature is that the dual-lintel divide the joint domain into three core zones from top to bottom. In order to study the mechanical mechanism of circle tubular steel column- I-shaped section dual-lintel joints in traditional style buildings， two all-welded inner joints and two all-welded exterior joints were tested in the quasi-static test. The wall thickness of the core zone was weakened in order to obtain the damage mechanism in the core zone of the joints. The test results indicated that the core area of the dual-lintel joint had three core zones， which consisted of upper lintels， lower lintels and circle tubular steel columns. The three zones of I-shaped section dual-lintel joints in traditional style buildings differed in their stresses， and were overall concentrated in the middle and lower core zones of the joint， with the lower core zone being the main damage area. The middle core zone was dominated by severe lateral buckling， while the lower core zone was deformed by bending shear in the direction of diagonal depression. The final damage of the inner joint was that the base material at the lower end of the lower core was torn and the crack passed through the welding process hole， whereas the failure mode of the exterior joint was the fracture of the weld between the upper flange of the upper beam and the column. The maximum shear stress of the lower core of the joint was derived， and the shear stress factor in the lower core was corrected considering the effects of axial compression ratio and joint form based on the test results.