Frequency and temperature dependent viscoelastic vibration damping capability of a novel local CLD treatment

As lightweight and stiffened structures, aircraft are prone to vibration. Constrained Layer Damping (CLD) treatment is a popular method to increase the vibration damping of such structures. Constrained by a top and bottom layer, the viscoelastic core layer is forced under shear strain and causes a dissipation of vibrational energy. However, the damping behaviour of viscoelastic materials is highly dependent on frequency and temperature, and has to be considered during the design process. In this paper, the influence of frequency and temperature on the damping behaviour of bromobutyl rubber is presented. The material is modelled by a generalized Maxwell model, which can be implemented in finite element (FE) calculations for damping layout. Additionally, a novel setup for local CLD treatment is introduced, causing higher shear strain in the core layer. The damping results are compared to those of different damping treatments. Finally, the impact of bromobutyl rubber on the damping capability of the local CLD treatment is examined for various excitation frequencies and temperature levels.