Different models of connection flexibility in dynamic analysis of plane frame systems

Abstract

Nowadays, in Vietnamese structural design standards for steel frames and semi-precast reinforced concrete structural frame systems, the connections of beams and columns are commonly considered as perfectly hinged or rigidly fixed. This is adopted because of the simplicity in design and analysis procedure but it is not consistent with the condition taking into account actual behaviour in practice of structural systems. The connections between columns and beams have partial restraint depending on the type of used connections. 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 connection flexibility in the case of lack of suitable analysis method. The paper presents the dynamic analysis of plane frame systems with different models of semi-rigid connections using finite element method. The used models in dynamic analysis are rotational spring and rotational-lateral spring. The analysis procedure was implemented using MathCad programming software and the results of this study will obtained by conducting of numerical examples. From there, the conclusions and recommendation of dynamic analysis for steel and semi-precast concrete frames with models of connection flexibility and the differences between used models will be proposed.