Abstract:A new type of SMA laminated variable stiffness horizontal universal damper was developed utilizing the superelastic properties of NiTi shape memory alloy (SMA) wires, and the essential configuration and working mechanism were introduced. The calculation model of damper restoring force-displacement hysteretic curve was established and the parameter analysis was carried out. Results shows that the restoring force-displacement hysteretic curve of the damper presented a full spindle shape, the damper possessed good energy dissipation capacity, self resetting function, large stroke and unique variable stiffness characteristics; the maximum stroke of the damper decreased continuously whereas the unit cycle energy dissipation increased at first and decreased afterwards with the pre-tension strain of SMA wire increasing from 0.03 to 0.06; with the increase of SMA wire diameter, the stiffness and energy dissipation capacity of the damper increased whereas the maximum stroke and equivalent damping coefficient remain unchanged; the maximum stroke and unit cycle energy consumption increased wheras the stiffness decreased continuously with the increase of the number of damper layer; with the number of SMA wires in each damper layer increasing from 8 to 16 and 32, the stiffness and unit cycle energy dissipation increased, however, the change of the maximum stroke and equivalent damping coefficient was not obvious.