| A new adjustable damper is evaluated in this study. The damper is capable of providing different levels of damping based on the fluid pressure differential across the piston and fluid flowing through an adjustable orifice. Such dampers can be used for seismic protection of structures. This study is aimed at evaluating the effectiveness of adjustable dampers for mitigation of earthquake excitations. The new damper is tested under cyclic and ramp loadings. From the tests, the damping properties are established. Analytical studies are performed based on the test results. A two-story base isolated structure with adjustable damper is studied analytically. The analytical model is subjected to several near-fault earthquakes. It is shown by means of experimental and analytical studies that the adjustable damper is effective in reducing the seismic response of base isolated buildings subjected to near-fault earthquakes. |
