A Novel Approach to the Design of Hybrid Anti-Vibration Mounts

Abstract

Vibration isolation of aerospace structures that support high precision instrumentations demand a novel design approach. In order to create a design that is suitable for use in harsh environments with no risk of drift in alignment of the structure, the commonly used viscoelastic elements should ideally be eliminated. The novel isolator proposed here is a space-frame structure that is folded in on itself to act as a mechanical filter over a defined frequency range. The design uses a genetic algorithm based geometric optimisation routine to maximise passive vibration isolation hybridised with a geometric feasibility search. To complement the passive isolation, an active system is incorporated in the design which in effect adds damping to the system. The active-passive structure is shown to achieve transmissibility of about 19 dB over a range of 1–250 Hz. The design has no or little consequent weight and cost penalties whilst maintaining its effectiveness with the vibration levels. The results indicate the promise of a new breed of anti-vibration mounting design.