VIBRATION CONTROL IN MACHINES AND STRUCTURES USING VISCOELASTIC DAMPING

Abstract The work on vibration control of machines and structures incorporating viscoelastic materials in suitable arrangements, is highlighted for situations involving vibration excitations over a broad frequency range. The principle involved is that of vibratory energy dissipation due to a damping as a result of deformation of viscoelastic materials. The characteristics of viscoelastic materials have to be suitably modelled in view of their dependence on several factors like type of dynamic excitation, temperature, strain, etc. The main objective of the paper is to review some of the salient work, done at I.I.T. Delhi, relating to constrained layer damping for structures, optimisation studies and support damping for rotor systems. Some results, which have either not been published or are not easily available, are also included. Brief reference to related work, carried out at other places, it also made, the list being by no means exhaustive, due to space constraints. Efforts have been made to predict the future trends in theoretical and experimental work in the analysis, optimisation and use of viscoelastically damped structures.