Abstract
The paper describes a numerical study on CHS (Circular Hollow Section) steel column semi rigid connections. Connections here is that gusset plates (flange plates) or H-beams are welded directly to columns. The numerical work was carried out by FEA with 118 model of the specimens subjected to tension or compression load through flange plates and 114 model of the subassemblage specimens under symmetrical loading. It was involved 90 numerical analyses of Finite Element models with parameters of the diameter to thickness ratio (D/t) and the flange width to diameter ratio (Bf/D). Evaluations of the numerical results showed as follows: (1) the affective parameters on the behaviour of the connections is the D/t and the Bf/D ratio, (2) the compression strength is less than the tension one in case of D/t >27, and it is not less than the tension strength in case of D/t <22, (3) the empirical formulae obtained by regression analysis estimate well the elastic-plastic behaviour of the connections.
