Dynamic analysis of plane frame systems with different models of connection flexibility

Abstract

Nowadays, in Vietnam, in the current design standards for steel frame and semi-precast reinforced concrete structural systems, the connections of main elements such as beams and columns are commonly considered as either perfectly hinged or rigidly fixed. This assumption is adopted because of the simplicity in design and analysis process but it is not consistent with the condition encountered and actual behaviour in practice of structural systems. The connections between columns and beams have partial restraint depending on the type of used connection. The presence of connection flexibility tends to reduce frame stiffness in comparison with the case of fully fixed connection and hence increases the frame’s natural period of vibration. However, it is also more time required because of complexity of analysis process with consideration of flexibility of connections in the case of lack of suitable calculation method.