TY  - BOOK
AU  - Muhr A H
AU  - Sulong M
AU  - Thomas A G
TI  - Rolling-ball rubber-layer isolators
PY  - 1997///
PB  - Journal of Natural Rubber Research
KW  - Rubber-layer isolates
N2  - A system has been developed for seismic isolation of light structures, with no restriction as to choice of deflection capacity, damping or period. It comprises: isolators consisting of balls rolling between tracks; damping provided by layers of dissipative material, such as rubber, bonded to the tracks and hence integral with the isolators; separate springs to provide a restoring force. The use of rubber layers to provide rolling resistance permits a very wide choice of effective damping level, and the rolling resistance can easily be arranged to be a preset function of displacement. The design of the isolators is thus more versatile than for sliding isolators, which are otherwise similar in concept. Experimental results are presented for the steady rolling resistance as a function of load, ball radius, rubber thickness, rubber nature and rolling velocity. The peak in horizontal force required to start the balls rolling depends on the length of time for which the load is applied before rolling starts as well as on the above parameters. This peak in force could be beneficial in providing resistance to wind loads, but if too high could prevent the isolation system operating in an earthquake
ER  -