Design of 1-3/0-3 viscoelastic composite layer for augmented active/ passive constrained layer damping of structural vibration
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In this dissertation, two kinds of viscoelastic composite (VEC) layers are proposed by the names of 1-3 and 0-3 VEC layers. The 1-3 VEC layer is comprised of the inclusion of unidirectional graphite wafers or strips, while the other one (0-3 VEC) is composed of a rectangular array of thin rectangular graphite-wafers. The objective in these designs of the VEC layers is to augment the damping in the unconstrained layer damping (UCLD), passive constrained layer damping (PCLD) and active constrained layer damping (ACLD) treatments of structural vibration. First, the1-3 VEC layer is employed as the damping layer in the UCLD and PCLD treatments of vibration of a substrate beam, and the corresponding damping mechanisms especially due to the graphite inclusions within the viscoelastic layer are investigated by developing a finite element (FE) model of the beam. The results reveal significantly enhanced magnitudes of the transverse shear and extensional strains within the viscoelastic phase for the presence of inclusions. So, the damping capacities of both the UCLD and PCLD treatments improve significantly. These observations motivate to extend the investigation for ACLD treatment of beams using the 1-3 VEC layer, and it is revealed that the active-passive damping in the ACLD treatment improves due to the use of 1-3 VEC layer instead of the conventional pure viscoelastic layer.
Supervisor: Satyajit Panda