Optimum frictional elements in sliding isolation systems

✍ Scribed by R.S. Jangid

• Book ID: 104269225
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 583 KB
• Volume: 76
• Category: Article
• ISSN: 0045-7949
• DOI: 10.1016/s0045-7949(99)00126-1

✦ Synopsis

The optimum friction coecient of a sliding system with a restoring force for the minimum acceleration response of a base-isolated structure under earthquake ground motion is investigated. The stochastic model of El-Centro 1940 earthquake which preserves the non-stationary evolution of amplitude and frequency content of the original record is used for the model of earthquake. The base-isolated structure consists of a linear ¯exible multi-storey structure supported on the sliding system. The sliding system is modelled to provide a friction force (ideal Coulombfriction type) and a linear restoring force. The non-stationary stochastic response of the isolated structure is obtained using the time dependent equivalent linearisation technique as the force-deformation behaviour of the sliding system is highly non-linear. The response of the system is analysed for the optimum friction coecient of the sliding base isolation system. The criterion selected for optimality is the minimisation of the root mean square top ¯oor absolute acceleration. The optimum friction coecient of sliding isolation system is obtained under important parametric variations such as: period and damping of the superstructure, ratio of the base mass to the superstructure ¯oor mass, the damping ratio of the isolation system, the period of base isolation system and the intensity of earthquake excitation. It has been shown that the above parameters have signi®cant eects on optimum friction coecient of the sliding base isolation system.