Performance of Multilayer Constrained Layer Damping Structures: A Comprehensive Study Using RKU, FEM, and Experimental Approaches

The complex dynamics of structures under external excitations, with emphasis on the design and analysis of Constrained Layer Damping (CLD) structures was studied using FEM and modified Ross-Kerwin-Ungar (RKU) model.

The 5-layer CLD structures consisting of mild steel substrate, NBR-PVC (5-5) 20HAF viscoelastic damping layers (2 no’s) paired with Aluminum (configuration-1) and GRP (configuration-2) as constraining layers (2 No’s) were fabricated. Series of vibration experiments were conducted on electrodynamic vibration shaker integrated with data acquisition system. Modal and harmonic analysis was also carried out using modified RKU, FEM to predict frequency response and system loss factor for two CLD configurations.

It is observed that, two CLD configurations exhibited substantial variation in the system loss factor (0.012 to 0.19), compared to the substrate, which is well below 0.01. Further, the CLD with Aluminum as constraining layer indicated superior damping performance compared to its counterpart GRP. The comparison of results from FEM and modified RKU method with experimental data revealed, deviations of approximately 5–15% and 15–23% respectively indicating relative accuracy of FE simulation data, especially in complex structural scenarios.

The study offers valuable insights into the distinct performances of different constraining layers, improves our understanding of the dynamic behavior of multilayer CLD structures.