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Multiobjective optimization for vibration reduction in composite plate structures using constrained layer damping
Published in Alphose Zingoni, Insights and Innovations in Structural Engineering, Mechanics and Computation, 2016
J.F.A. Madeira, A.L. Araújo, C.M. Mota Soares, C.A. Mota Soares
Constrained Layer Damping (CLD) is an efficient way of reducing vibration levels and sound radiation in lightweight structures. The CLD treatments are applied as patches on structural surfaces, consisting of a viscoelastic material layer with a constraining layer on top. This viscoelastic layer, which is sandwiched between the base structure and the stiffer constraining layer, deforms mainly in shear due to the different displacements between the two constraining materials. The result is the conversion of energy into heat which reflects in added damping to the structure. The pioneering work on CLD can be traced back to Kerwin (1959) who developed a simplified theory to calculate the loss factor of a plate with a CLD treatment. Different approaches were presented afterwards for the modeling of structures with viscoelastic core and the calculation of energy dissipation (DiTaranto 1965, Mead & Markus 1969, Rao & He 1993). Active Constrained Layer Damping (ACLD) is an alternative form of CLD that uses an active piezoelectric layer to replace the passive constraining layer in order to increase damping (Baz 1998, Shen 1994). ACLD is quite effective in the low frequency range but is more expensive and more complex to implement than the passive CLD.
Evanescent morphing for tuning the dynamic behavior of composite lightweight structures: Theoretical assessment
Published in Mechanics of Advanced Materials and Structures, 2021
Klaudiusz Holeczek, Bingquan Zhou, Pawel Kostka
Another group of passive damping solution is based on a selective implementation of different kinds of damping layers. A FRP-compatible form of such a measure is the integration of damping layers or patches of different size and shape between the reinforcing plies at different depths during the manufacturing phase [13]. The damping mechanism is based in this case on the shear induced between the damping layer and the constraining composite layers. A more general approach consists in the application of damping layers on the component’s surface after its fabrication. In this configuration, extra constraining top layers are typically applied for the shear induction. Such solutions are usually referred to as constrained layer damping (CLD) treatment and are widely used for vibration damping in vehicles and machines. Governing mathematical models of damping mechanism of CLD with viscoelastic materials and basic kinematic dependencies were established [14]. Many derivatives assuming additional deformation components, e.g. [15], are objects of investigation. The size, shape, and position of CLD can be determined separately for each problematic component’s vibration mode [16] enabling an efficient tuning of the component’s dynamic behavior for a number of application-relevant vibration modes. Such solution is therefore especially suitable for influencing of a relatively low number of vibration modes and could be therefore successfully implemented in applications with well-defined and narrow excitation spectrum.