Analysis of Seismic Behaviour of Welded Steel Connections and Frames with Differently Constructed Connections

Connection construction has an important effect on the ductility and capacity of steel structures subject to seismic excitation. In order to study the seismic behaviour of steel connections and frames with differently constructed members and connection, nonlinear 3-D finite element analyses based on ABAQUS have been conducted. Firstly, the use of multi-scale nonlinear finite element models has been proved appropriate after comparing their predictions with those of tests, including the hysteretic behaviour of nine steel variously constructed members and connections. Secondly, nine steel frame multi-scale models provided with different member and connection designs were established, and dynamic elasto-plastic seismic performance evaluation analyses were carried out. The results show that: all different connection and member designs studied do not have significant effects on the macro seismic behaviour of steel frames, but they does exist an improvement of the fracture tendency at welded toe for failure forms to be affected. Reinforced construction of connections results in no base shear forces increase. Reduced construction details, such as the use of web holes and 'dog bone' members, does not seriously weaken the basic behaviors of connections and does provide good energy dissipation characteristics when subject to earthquake excitation.