Evaluation of seismic behavior of eccentric braced dual steel frames equipped with shape memory alloys

Due to the suitability of the eccentric bracing system in terms of optimal performance and ductility on the other hand, as well as the effect of reversible materials such as shaped memory alloy in reducing the residual displacement at the end of the earthquake and seismic evaluation of structures with the different number of stories, structures with eccentric bracing dual steel bending frame system within 5, 10 and 15 stories equipped by shaped memory alloy rods, were subjected to the nonlinear dynamic analysis of time history. Maximum absolute displacement of the roof and relative displacement of stories, the maximum residual displacement of the roof, maximum base shear, and roof acceleration in the desired frames were evaluated and compared. Survey results showed that the absolute and relative inter-story drift in all three models due to the lower elastic modulus of shape memory alloy has been greater than models that have not been equipped with shape memory alloys. On the other hand, the residual displacement values of structural models due to the super-elastic property of the shape memory alloy materials and the shear stories and acceleration of the roof of structural frames due to the increase in period time and structural softness have shown a sudden sharp drop compared to models that have not been equipped with shape memory alloys. Comparison of structural responses in different models also showed a further reduction effect on the plastic displacement of the 5-stories model and base shear and roof acceleration of 10 and 15-stories structures.