Flexibility of beam to column connections in hollow construction

The objective of this study is to predict the behaviour of cold-formed steel hollow rectangular beam to column joints made of direct welded connections. The column chosen is a stub column so that the overall buckling of the column does not influence the joint behaviour. The beam chosen is a short-span beam with a concentrated load being applied at the free end to test the joint under such increasing loads. These joints with columns are so designed that major and minor axes of columns are used as parameters to generate different test cases and these joints are tested to failure. In all the experiments conducted, the stiffness of the connection, the ductility characteristics and the moment rotation behaviour are studied. The Moment–rotation characteristics of the joints are idealized as either bilinear or trilinear form and this can be used to predict load deflection behaviour of such beam-column joints. Based on the study, different degrees of flexibility effects can be included on these types of joints, so that frame behaviour can be predicted. These results paved the way for generating a simplified beam model including the flexibility of connection and this is validated by the Finite Element models using ANSYS and experimental results.