عنوان مقاله [English]
Shape Memory Alloys (SMAs) are new material in structural engineering. They can be used as reinforcement for the concrete walls. In this research, a numerical
model was first developed based on an experimental test of a tall reinforced
concrete wall with steel reinforcement subjected to an earthquake, and the
numerical model responses were compared to the experimental model. Then, three other approaches were examined; first, the shape memory alloys were replaced only as vertical bars on the first story; in the second one, Shape memory alloy bars were replaced only on the first and sixth stories; and in the third
approach, the whole vertical bars were replaced with shape memory alloy bars.
Nonlinear time history analysis and comparison of model responses were
performed. In addition, the parametric study of the responses was also done by
changing some model characteristics such as axial force and earthquake
intensity. In all three approaches with the shape memory alloy bars, the base
moment demand value decreased by approximately 15% compared to the model with steel reinforcement. In the moment demand diagram, the amount of moment demand at the mid-height of the structure is relatively increased compared to the base moment demand. This is due to the effect of higher modes on wall behavior. The moment diagram graph is not uniformly decreasing along the height is not like a straight line. In addition, parametric study of the responses is also performed
by changing some model characteristics such as axial force and earthquake
intensity. With the formation of a plastic hinge at the base of the wall,approximately, the amount of moment demand in this area remains constant and the effect of higher modes increases the moment demand at the mid-height of the structure and may result in the formation of another plastic hinge at the mid-height of the structure.