A modified friction damper for diagonal bracing of structures

In this paper, the dynamic behavior of a recently developed friction damper has been demonstrated. It is made from nine steel stripes and nine high strength steel bolts and is applied in the diagonal bracing of structures. This device has a square geometric shape and should be installed in the square spans. During this research work, a prototype of the modified friction damper was tested by a universal machine. Then the damper was installed inside a SDOF steel frame and tested by the shaking table under several earthquake excitations. For numerical assessment of the system, the model of SDOF frame was created in SAP2000 and analyzed under the same excitations which had been applied during the shaking table tests. By comparing the results obtained from SAP2000 to those of experimental tests, the validity of numerical modeling was proved. In order to assess the behavior of damper in multi-story buildings, the model of a four story frame, with and without the modified damper, was created in SAP2000 and analyzed under several seismic records. The results were indicating that the lateral displacements and the base shears of the multi-story building have been significantly reduced by the installation of this modified energy absorber and a considerable energy has been dissipated by the damping system.