PASSIVE VIBRATION CONTROL VIA UNUSUAL GEOMETRIES - EXPERIMENTS ON MODEL AEROSPACE STRUCTURES

In a previous paper [1], one of the present authors described a method whereby passive vibration isolation could be designed into a lightwei ght aerospace structure by the adoption of unusual geometric configura tions. This was achieved by the use of Genetic Algorithm methods to op timize the isolation characteristics of the structure. The current bri ef paper follows on from that work and describes an experimental inves tigation into the performance of the structures designed in the earlie r study. It is shown that, although the detailed behaviour of the expe rimental models is somewhat different from that predicted theoreticall y, the same broadband vibration isolation characteristics shown by the theory exist in practice. It is seen to be possible to achieve an ave rage of 50 dB isolation in the vibrational energy transfer between the ends of a network of beams over a 100 Hz bandwidth in an essentially undamped structure. These experimental results are sufficiently encour aging that work is now underway to apply Genetic Algorithm based desig n methods to more complex structural vibration problems.