STATE-OF-THE-ART REVIEW OF SYMMETRIC AND ASYMMETRIC FRICTION CONNECTIONS: SEISMIC BEHAVIOR AND DESIGN METHODS

This paper reviews the state of the art of symmetric and asymmetric friction connections in the last 40 years. The frictional connections can be employed to dissipate seismic energy and mitigate seismic response of structures. Low damage of structures and its toughness with the frictional connections can be achieved through proper design. To achieve stable and repeatable hysteretic performance is one of the main targets of the studies in this field. Friction and wearing mechanisms occurring on the sliding surfaces in both the microscopic and macroscopic levels are introduced. The effect of different shim materials on the seismic performance of friction connections is discussed in the viewpoint of friction and wearing. The effect of bolt clamping forces and surrounding atmosphere on the seismic behavior of frictional connections are described. Applications of the frictional connections in steel structures are illustrated in three aspects, namely, braces, beam-to-column joints and column base joints. Design methods for the above joints are also introduced. Existing problems in the friction connections are summarized, and suggestions for future study are made.