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Proceedings of the International Conference on
Advances and New Challenges in Earthquake
Engineering Research, Hong Kong Volume
DYNAMIC ANALYSIS OF FRICTION-DAMPED STRUCTURES
L. L. Chung 1 , L Y. Wu 2 , and Y. P. Wang 3
1 National Center for Research on Earthquake Engineering, Taiwan
Department of Civil Engineering, National Taiwan University, Taiwan
Department of Civil Engineering, National Chiao-Tung University, Taiwan
ABSTRACT
In this paper, the feasibility of friction damper as a passive control devices is verified through
theoretical and numerical investigation. The stiffness and damping may be enhanced simultaneously
by adding friction dampers to the conventional structures. Significant reduction in dynamic response
can be achieved. After the friction dampers are added to the structure, friction mechanism makes the
structural system highly non-linear and the motion of the friction damper may be shifted from the nonsliding
mode to the sliding mode, and vise versa. No matter in the non-sliding or sliding mode, either
the kinematic or kinetic condition is known. A simple and efficient numerical method is developed for
the dynamic analysis of friction-damped structures. Only a single equation of motion is used to
describe the dynamic system for both non-sliding and sliding modes. The stability and accuracy are
guaranteed even though the time step of integration remains constant during the process of the
solution.
INTRODUCTION
Friction damper is one of the promising passive control devices for civil engineering structures. The
stiffness and damping may be enhanced simultaneously by adding friction dampers to the conventional
structures. With appropriate allocation of friction dampers, vibration energy will be dissipated
efficiently when the structure is subjected to environment loads. The research on slotted bolted
connection for friction damper can be traced back to 1976 (Venuti 1976). The friction damper consists
of two outer plates and one inner plate. Circular holes are drilled on the outer plates and slotted holes
are drilled on the inner plate for the bolted connection so that relative sliding between the inner and
outer plates is allowed. Energy is dissipated through friction mechanism (Pall and Marsh 1979;
Fitzgerald et al 1989; Roik et al 1988). In 1982, X-shaped bracing system was used to mount the
friction damper (Pall and Marsh 1982). The stiffness is induced from the tension of the bracing. At
the connection of the X-shaped bracing, energy is dissipated by the friction mechanism of the link and
braking pad (Filatrault and Cherry 1987; Pekau and Guimond 1991). Such kind of friction damper has
been put into real application (Pall et al. 1993).