Optimum Design and Control of Active Constrained Layer Damping

Abstract

Conventional Passive Constrained Layer Damping (PCLD) treatments with viscoelastic cores are provided with built-in sensing and actuation capabilities to actively control and enhance their vibration damping characteristics. The design parameters and control gains of the resulting Active Constrained Layer Damping (ACLD) treatments are optimally selected, in this paper, for fully-treated beams using rational design procedures. The optimal thickness and shear modulus of the passive visco-elastic core are determined first to maximize the modal damping ratios and minimize the total weight of the damping treatment. The control gains of the ACLD are then selected using optimal control theory to minimize a weighted sum of the vibrational and control energies. The theoretical performance of beams treated with the optimally selected ACLD treatment is determined at different excitation frequencies and operating temperatures. Comparisons are made with the performance of beams treated with optimal PCLD treatments and untreated beams which are controlled only by conventional Active Controllers (AC). The results obtained emphasize the potential of the optimally designed ACLD as an effective means for providing broad-band attenuation capabilities over wide range or operating temperatures as compared to PCLD treatments.