A feasibility study on pre-compressed partially bonded viscoelastic dampers. (15th December 2019) - Ghotb, M.R.
Highlights: An innovative sandwich-type pre-compressed, partially bonded, viscoelastic damper is introduced. The elastomeric pads of the damper are reinforced by layers of carbon fiber fabric. The fiber-layers provide a new source of energy dissipation in the elastomeric pads and the damper. The elastomeric pads are subjected to a permanent compression to exhibit a higher effective damping. The pads are partially bonded, to exhibit rollover shear deformations and decreased effective stiffness. Abstract: The conventional viscoelastic damper devices employ high damped elastomeric pads that are chemically bonded at their entire contact surfaces to the steel plates of the device. The hysteretic load-deformation characteristics of the device are governed by the inherent response properties of the elastomeric material under cyclic shear deformations. The high damped viscoelastic material of the device is typically made of a particular copolymer of patented formulation. The main objective of this paper is to improve the hysteretic characteristics of a viscoelastic damper by applying physical changes to the configuration of its viscoelastic pads. As such, innovative pre-compressed partially bonded viscoelastic damper devices have been introduced. The proposed dampers employ fiber-reinforced viscoelastic pads that are partially bonded to the inner and outer steel plates of the damper, and are subjected to a desired level of permanent pre-compression. A set of full scale prototype damper devices of different geometrical configurations have been examined experimentally. Results of cyclic shear tests indicate that the pre-compressed stresses increase the effective inherent damping of the viscoelastic material. Moreover, the fiber reinforcing layers provide an additional source of energy dissipation as the partially bonded pads exhibit rollover deformations under cyclic shear loads. Based on the results of this proof-of-concept study, the pre-compressed partially bounded viscoelastic dampers are found to be quite feasible.