Viscoelastic Damping Technologies-Part II: Experimental Identification Procedure and Validation

Abstract

c � HyperSciences.Publisher Abstract: This is the second of two companion articles addressing an integrated study on the mathematical modeling and assessment of the efficiency of surface mounted or embedded viscoelastic damping treatments, typically used to reduce structural vibration and/or noise radi- ation from structures, incorporating the adequate use and development of viscoelastic (arbitrary frequency dependent) damping models, along with their finite element (FE) implementation, and the experimental identification of the constitutive behavior of viscoelastic materials. In the first article (Vasques, C.M.A. et al., Viscoelastic damping technologies-Part I: Modeling and finite element implementation, Journal of Advanced Research in Mechanical Engineering 1(2): 76-95 (2010)) viscoelastic damping has been tackled from a mathematical point of view and the implementation, at the global FE model level, of time and frequency domain methods, namely the internal variables models, Golla-Hughes-McTavish (GHM) and anelastic displacement fields (ADF), and the complex modulus approach based ones, direct frequency response (DFR), iterative modal strain energy (IMSE) and an iterative complex eigensolution (ICE), respectively, were described and formulated. This second article is a natural extension of the first one. It presents a generic methodology to identify the complex shear modulus of viscoelastic materials. In this case, the complex shear modulus of the well-known viscoelastic material 3M ISD112 is identified and up-to-date values for this material are used and curve-fitted in order to obtain the modeling parameters of the GHM and ADF models. Afterward, a viscoelastic sandwich (three-layered) plate specimen and the correspondent FE model are considered numerically and experimentally. Measured and predicted frequency response functions (FRFs) are compared with the purpose of assessing the performance of the damping models presented in the companion article. The analysis allows to assess the validity of the methodology to determine the frequency dependent complex modulus, the GHM and ADF parameters identification procedure and the outcomes and drawbacks of the DFR, IMSE, ICE, GHM and ADF viscoelastic damping modeling strategies and their FE implementations, with the aim of assisting structural designers in the selection of the most appropriate viscoelastic damping modeling approach for their specific needs.