SEMIANALYTICAL TECHNIQUES FOR THE DETERMINATION OF THE DYNAMIC-RESPONSE OF EQUIPMENT IN STRUCTURES SUPPORTED ON COULOMB-FRICTION ELEMENTS

Techniques for the analysis of equipment in structures supported on a Coulomb friction type support that is subjected to harmonic and earthq uake ground motion are presented. The behaviour is governed by two pha ses-a sliding phase and a non-sliding phase. Since the behaviour in ea ch of the phases is linear, an analytical expression for equipment res ponse can be obtained in terms of the roots of an appropriate characte ristic polynomial. The times of phase transition are determined by an iterative scheme. The methodology is accurate, less computationally in tensive, and avoids the difficulties that can be encountered with stan dard numerical integration techniques for highly non-linear systems.