ahmad modhej - Department of Civil Engineering, college of Technical and Engineering, Saveh Branch,Islamic Azad University,Saveh,Iran.
Seyed Mahdi zahrai - professor school of civil eng ,college of eng,the university of tehran tehran iran
mansour ziaeifar - associate prof international institute of earthquake eng.&seismology IIEES,tehran Iran

In the last few years, dampers with viscoelastic material as passive energy dissipation devices have been considered with dual behavior in the modern methods of seismic performance based design. In these new dampers, energy dissipation of viscoelastic material, unlike ordinary viscoelastic dampers which obtained by shear strain is provided by amplified axial strain. In this paper, a new passive energy dissipation device called Visco-Plastic damper with dual behavior is introduced and investigated. This device combines and enhances many of the proven characteristics of both displacement-dependent and velocity-dependent devices

High Damping Rubber (HDR); Hyperelasticity; Viscoelastic damper