Filiatrault, Tremblay, and Kar 2000
The evolving concept of the use of passive energy dissipators in seismic design is discussed in this paper. In particular, a self-centering friction mechanism is analyzed numerically and evaluated experimentally. Characterization component test are conducted along with half scale shake table testing in order to assess the seismic performance of the damper system.
System Concept
The seismic damper consists of a ring spring, or a friction spring, as the dominant energy dissipator. The assembly consists of outer and inner rings. As the damper is axially loaded, the rings begin to slide on the conical friction surface. The outer ring is put into circumferential tension and the inner right experiences compression force. Characterization test of the damper exhibited force-displacement hysteresis loops which were self-centering, repeatable, stable, identical in tension-compression, and identically at almost all frequencies considered.
Experimental Study, Results and Discussion
Shake table test were performed on a half scale specimen representing a single-story MRF. Lateral load resistance was provided by rigid connections between the floor beam and the columns as well as a bracing member. Tests were conducted for the specimen with and without the damper retrofit. The prototype model was subjected to a push over analysis and four different seismic simulations of the 1940 El Centro earthquake record.
The friction spring damper provided effective reduction of lateral displacement and acceleration levels. Hysteresis loops, resembling those found in the characteristic tests, were also found in the shake table tests proving the self-centering and energy dissipation concepts. The energy dissipation in all tests were found to be sufficient to protect the structure from undergoing severe inelastic deformations.
Reference
Filiatrault, A., Tremblay, R., and Kar, R. (2000). ”Performance Evaluation of Friction Spring Seismic Damper,” Journal of Structural Engineering, 126(4), pp. 491–499.