The response of lightweight equipment in structures supported on resilient-friction-base isolators (R-FBI) subjected to harmonic ground motion and various earthquake ground motions is examined. The equipment-structure base system is modeled as a three degree-of-freedom discrete system (SDOF subsystems). An efficient semi-analytical numerical solution procedure for the determination of equipment response is presented. Parametric studies to examine the effects of subsystem frequency (isolator, structure, equipment), subsystem damping, mass ratio, friction coefficient and frequency content of the ground motion on the response of the equipment are performed. The equipment response on a fixed-base structure subjected to ground motion is also calculated. Friction type isolation devices can induce high frequency effects in the isolated structure due to the stick-slip action. These effects on equipment response are examined. The results show that the high frequency effect in the structure generated from a friction-type base isolator doesn't, in general, cause amplifications in the response. The R-FBI system appears to be an effective aseismic base isolator for protecting both the structure and sensitive internal equipment. / Graduation date: 1992