Farzad hatami - Assistant professor / Institute of Petroleum Industry
ali ghamari - M.sc . structure student / azad islamic univercity-yazd unit

A reinforced concrete buildings are usually designed as a moment resisting frame or frame with a concrete shear wall. Steel shear walls can be used in lateral force bearing systems in the design of new buildings and the retrofit of existing ones . In slender shear walls , steel plates are expected to buckle along compressive diagonals under relatively small shear forces . after buckling , the tension field action of the diagonal become the primary mechanism to resist shear forces .In this paper , the retrofit of concrete frames by steel shear walls are considered and their seismic parameters will calculated. A numerical approach has been used to investigate the effect of chainging of thickness of the steel plate on system behavior under lateral load. The results show that the steel plate goes into nonlinear zone while the boundary frame remains in linear zone. Also , the steel plate is able to yield at predetermined force level and dissipate the seismic energy.

Concrete , frame ,Steel shear wall ,Nonlinear ,Behavior