Optimal Design For Using Smart Materials in Shear Walls in Different Stories Level For Rehabilitation of Reinforced Concrete Buildings

Background and The main purpose of seismic design is to increase ductility and seismic energy dissipation by entering the structures into the non-linear area. Many concrete structures are destroyed and reconstruct after the earthquake due to permanent over-deformations and high cost of re-construction. In order to prevent the destruction of these structures, we need materials with the feature of hyperelasticity and the capacity to recover its original shape after unloading. The use of shape-memory alloys in concrete shear walls to solve this problem has been proposed by researchers. The most important characteristics of shape memory alloy is the capability of maintaining their original shape and ultra-reactionary. These alloys having super-elastic behavior can tolerate up to about ten percent strains without leaving residual strains. With these features, the use of these alloys in the structure can improve its seismic behavior. However, due to the high cost and complex implementation of this type of alloys, their use is limited. So, it is necessary to optimally use of them using an optimal design.
the behavior of concrete frames with the shear walls improved by shape-memory alloys has been investigated in different floors, three, five, seven and nine concrete frames with different modes using shape-memory alloys materials under non-linear dynamic analysis time of the history by finite element software. In this study, we have tried to examine the optimal placement of the shape-memory alloy.
In this study, the parameters of floors relative lateral displacement, floors residual relative lateral displacement, and foundation cutting have been studied. Reducing the structure residual displacement and consequently, reducing the cost of rebuilding after the earthquake can be mentioned as the main advantages of using shape-memory alloys.
according to the findings of this study, the behavior of the structures in which, shape-memory alloy is used in the first thirty percent of the height of the structure, has little difference with the structures in which, shape-memory alloy is used in their all floors. So, in case of using shape-memory alloy materials in only 30% of the height of buildings, the cost of smart armatures is reduced to one-third and it is and recommended that shape-memory alloys are only used in 30% of height of the intended structure.