Experimental research on seismic behavior of unstiffened overlapped CHS K-joints.

Quasi-static tests on four full-scale unstiffened overlapped CHS K-joints specimens with welded and non-welded hidden welds were conducted under low cycle load to study the behavior of unstiffened overlapped CHS K-joints of truss structure of steel pipe. The deformation characteristics, failure mode and energy dissipation were investigated. The hysteretic loops, skeleton curves, bearing capacity, ductility and energy dissipation were obtained. Test results indicate that the bearing capacity of unstiffened overlapped CHS K-joints is affected with welded and non-welded hidden welds, however, the hysteretic behavior of the joints is not very significantly affected. The typical failure mode is the local buckling of bracing member and the connecting weld damage between the braces and the chord member. Hysteretic property of the joints in which the hidden weld is non-welded is much better than that of the joints with welded hidden weld. The hidden weld that is non-welded deforms 1. 1-1.2 times more than the welded hidden weld. [ABSTRACT FROM AUTHOR]