Influence of Temperature on FLD and CLD Damping Treatment

The damping capabilities of viscoelastic materials depend heavily on the operating temperature. Since these materials are used for passive vibration damping, it is necessary to determine the damping properties of selected materials across a range of temperatures. This paper presents the results of an experimental investigation into the effect of temperature on the damping performance of viscoelastic materials applied to aluminium cantilever beams using free-layer damping (FLD) and constrained-layer damping (CLD) techniques. Butyl rubber and bituminous materials were experimentally tested by modal analysis over a temperature range from 22 °C to -2 °C. Frequency response functions, resonance frequencies, resonance amplitudes, and modal loss factors were determined for selected bending modes. The results show that CLD provides better damping at room temperature, particularly for butyl rubber, due to enhanced shear deformation in the viscoelastic layer. However, as the temperature decreases, material stiffening alters the damping efficiency, and FLD becomes more competitive or superior in several modes. The findings confirm that passive damping effectiveness is strongly dependent on temperature, material type, and vibration mode.