Title: The Deflection Capacity of Rubber Anti-Seismic Bearings

Author(s): A. H. Muhr

Publication: Symposium Paper

Volume: 164

Issue:

Appears on pages(s): 685-718

Keywords: Bearings; failure; rubber; shear properties; stability.

DOI: 10.14359/14323

Date: 11/1/1996

Abstract:
The linearised beam-column theory for the mechanics of laminated bearings is summarised and theory is presented for the "lift-off" behaviour seen at large shear deflections when bearings are located in recesses, rather than bolted. Experiments show that an axial load increases the dynamic shear stiffness and damping of a single high damping natural rubber layer, but in accord with the theory the shear stiffness of laminated bearings is reduced by an axial load while the damping is increased. Results of tests to failure for 17 permutations of axial load and bearing specification show that the shear capacity exceeds 70% of the plan dimension in all cases except for a squat design with thin endplates located in a recess. The shear capacity of such bearings is limited by yield of the endplates rather than rupture or instability.