Energy Dissipation Bracing Systems in Steel Frames Using FRP Composite Materials

Abstract

Passively damped bracing systems in steel frames, in which the conventional materials of the joint are replaced by high damping viscoelastic materials, have the potential of being effective practical means for passive vibration control of dynamically loaded civil engineering structures. However, this potential can be realized only if the associated structural penalties are reduced within acceptable limits. This paper describes a rational methodology for the development of an advanced joining type for structural systems capable of providing enhanced dissipation of vibration energy without serious penalties in strength, stiffness, or weight characteristics. One such configuration is that of a V-type bracing system with a joint which provides a beneficial deformation coupling between the direction of load transfer and less critical offset directions. A comprehensive parametric study has been carried out in order to establish design guidelines for favorable tradeoffs between damping benefits and the associated stiffness and strength penalties in an FRP V-type joint. The results are compared with the corresponding tradeoffs for a V-type joint made from conventional materials.