ROBUST-CONTROL OF ACTIVE CONSTRAINED LAYER DAMPING

Conventional Passive Constrained Layer Damping (PCLD) treatments with visco-elastic cores are provided with built-in sensing and actuation c apabilities to actively control and enhance their vibration damping ch aracteristics. The control gains of the resulting Active Constrained L ayer Damping (ACLD) treatments are selected, in this paper, for fully treated beams using the theory of robust controls. In this regard, an optimal controller is designed to accommodate the uncertainties of the ACLD parameters, particularly those of the visco-elastic cores which arise from the variation of the operating temperature and frequency. T he controller is also designed to reject the effects of the noise and external disturbances. The theoretical performance of beams treated wi th the optimally controlled ACLD treatment is determined at different excitation frequencies and operating temperatures. Comparisons are mad e with the performance of beams treated with PCLD treatments. The resu lts obtained emphasize the potential of the optimally designed ACLD as an effective means for providing broadband attenuation capabilities o ver a wide range of operating temperatures as compared to PCLD treatme nts. (C) 1998 Academic Press Limited.