Constrained-layer damping

About: Constrained-layer damping is a research topic. Over the lifetime, 795 publications have been published within this topic receiving 15758 citations.

Experimental investigation of electromechanical surface damping

Abstract: Electromechanical Surface Damping (EMSD) is a hybrid technique that incorporates constrained layer damping (CLD) and shunted piezoelectric element methods for the suppression of vibration in light beam-like or plate-like structures. The EMSD technique enhances the damping effectiveness (peak amplitude suppression) at targeted resonant frequencies, and may therefore be used to extend the damping effectiveness of the constrained layer damping technique over a broader temperature and frequency range than CLD alone. This performance enhancement was demonstrated experimentally by comparing the steady state frequency response of partially treated cantilever beams with that of an untreated beam. The experimental results also agreed with the results of a corresponding analytical model.

Experimental and Finite Element Analysis of Stand-Off Layer Damping Treatments for Beams

Abstract: Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) damping treatments are presently being implemented in many commercial and defense designs. In a PSOL damping treatment, a stand-off or spacer layer is added to a conventional passive constrained layer damping treatment. In an SSOL damping treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL damping treatments. In these beams, the bonding layers used to fabricate these treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modeling delamination.Copyright © 2007 by ASME

Application of viscoelastic damping for passive vibration control in automotive roof using equivalent properties

Abstract: In this study, a simplified approach to modeling the dynamic characteristics of passive constrained layer damping treatments in finite element models is presented. The basic concept is to represent multi-layered composite structures using an equivalent single layer. The equivalent properties are obtained by using the RKU (Ross, Kerwin and Ungar) equations. Comparisons are given between results obtained by the dynamic analysis of the simple models implemented in MSC/NASTRAN and by test measurements. Surface damping treatments are applied to automotive panels as well as simple structures. Using the proposed equivalent modeling technique, higher computational efficiency for the damped composite structures has been obtained.

Topology Optimization of Constrained Layer Damping Structures Subjected to Stationary Random Excitation

Abstract: This paper deals with an optimal layout design of the constrained layer damping (CLD) treatment of vibrating structures subjected to stationary random excitation The root mean square (RMS) of random response is defined as the objective function as it can be used to represent the vibration level in practice To circumvent the computationally expensive sensitivity analysis, an efficient optimization procedure integrating the pseudoexcitation method (PEM) and the double complex modal superposition method is introduced into the dynamic topology optimization The optimal layout of CLD treatment is obtained by using the method of moving asymptote (MMA) Numerical examples are given to demonstrate the validity of the proposed optimization procedure The results show that the optimized CLD layouts can effectively reduce the vibration response of the structures subjected to stationary random excitation

Constrained layer damping system and method of making the same

Abstract: A method of producing a constrained layer damping system including a constraining layer, a damping layer, a viscous thermally-activated decoupler (VTAD) layer and a base blank layer. The method includes the steps of blanking a constraining layer, applying a damping layer to the constraining layer to form a constraining/damping construct. A VTAD layer can be applied onto the damping layer to form a layered constraining/damping/VTAD construct in which the VTAD layer has at least one exposed surface. The exposed surface of the VTAD layer on the constraining/damping/VTAD construct is pressed onto a cleansed side of a base blank layer to form a constrained layer damping system.