Constrained Layer Damping Treatment: Analysis of multi-strip application on thin plates

This paper focuses on analysing the effects of using multiple strips of Constrained Layer Damping (CLD) treatments to cover entirely a thin aluminium plate and assess the vibration performance for various strips orientation. In particular, for a fixed type of CLD treatment, three strips orientation are considered: (i) parallel to the long axis of the plate, (ii) perpendicular to the long axis, and (iii) 45^º to the long axis. By using both experimental and Finite Element (FE) modelling, it is shown that depending on the mode shape curvature and corresponding nodal line positions, the strip orientation would strongly affect the amount of energy that can be dissipated at one particular resonance. An approximate topology optimisation technique is investigated to target the first bending mode of the structure and is validated experimentally. This technique involves optimising a uniform CLD topology for maximum stiffness (using a topology optimization feature of a FE commercial software) and then manually locating optimal strip placement by taking into account orientation effects. (paper)