BEARING CAPACITY FORMULAS OF MULTI-PLANAR DKT-JOINT CONTAINING INTERNAL STIFFENERS UNDER AXIAL COMPRESSION

For the construction of steel structures of Beijing Daxing International Airport Terminal, and based on the completed full-scale multi-planar DKT-joint tests, 192 groups of finite element models with different parameters are simulated and analyzed to further study the mechanical mechanism of the DKT-joint. The influences of opening size, thickness and quantity of stiffeners on mechanical properties of the multi-planar DKT-joint are investigated. Multiple nonlinear regression towards the design and ultimate bearing capacity of the multi-planar DKT-joint containing various stiffener arrangements under axial compression is conducted, and the magnification coefficient η for design value and ultimate capacity of the DKT-joint is obtained. The formulas of design value and ultimate capacity of the multi-planar DKT-joint containing internal stiffeners are derived based on current Standard for design of steel structures. Experiments and finite element analysis (FEA) results indicate that the formulas of design value and ultimate capacity of the multi-planar DKT joint containing internal stiffeners meet the precision requirements well, and can provide reliable reference for the design of similar joints in practical engineering.