Analytical and experimental results demonstrate that the performance improvements from active control systems can also be achieved with passive and semi-active fluid dampers. However, passive or semi-active fluid dampers offer the advantages of low cost, no or minimal demand for external power, longevity and reliability.
This paper describes a large variety of passive energy dissipating devices which can be used within a structural system to absorb seismic energy. These devices can produce significant reductions of inter-story drifts in moment- resisting frames. Furthermore, these devices may under elastic conditions, reduce the design forces.
This experiment demonstrated how various types of shock absorbers can reduce the overall shock response spectra of a structure subjected to high impact shock. This was accomplished by measuring the acceleration on a weight dropped onto three different shock absorbers from various heights and analyzing the resulting data. A baseline test was performed with a steel hard mount. This was followed by tests with three different soft isolation mounts; a half inch thick neoprene pad, a urethane rubber tube on its side and a hydraulic liquid spring type shock absorber. Results show that both the dominant frequencies and the peak acceleration get lower as the isolation system gets softer. This information can be valuable in the design of isolation systems.
This specification covers the set of ten linear fluid viscous dampers along with their mounting brackets and pins for the Rockwell Building located at Jamboree Road and Birch in Newport Beach, California. These dampers provide an output force in either tension of compression that is directly proportional to the relative velocity between the two ends of the dampers. The damper output force varies only with velocity and does not change with damper stroke position or orientation angle. The function of the dampers is to absorb earthquake energy, thereby reducing the amount the building moves when an earthquake occurs.