Analysis of Sandwich Plates with Isotropic Face Plates and a Viscoelastic Core

Abstract

Experimental and analytical validations of a Galerkin assumed modes analysis of sandwich plates are presented in this paper. The 3-layered sandwich plate specimen consists of isotropic face-plates with surface bonded piezo-electric patch actuators, and a viscoelastic core. The experimental validation is conducted by testing sandwich plates that are 67.31 cm (26.5 in.) long, 52.07 cm (20.5 in.) wide and nominally 0.16 cm (1/16 in.) thick. The analysis includes the membrane and transverse energies in the face plates, and shear energies in the core. The shear modulus of the dissipative core is assumed to be complex and variant with frequency and temperature. The Golla-Hughes-McTavish (GHM) method is used to account for the frequency dependent properties of the viscoelastic core. Experiments were conducted on symmetric and asymmetric sandwich plates with aluminum face-plates under clamped boundary conditions to validate the model for isotropic face-plates. The maximum error in damped natural frequency predictions obtained via the assumed modes solution is <11 percent. Analytical studies on the influence of the number of assumed modes in the Galerkin approximation have been conducted. Error in the first plate bending mode is 112 percent when only a single in-plane mode is used; error reduces to 3.95 percent as the number of in-plane modes is increased to 25 in each of the in-plane directions. [S0739-3717(00)00703-0]

Analysis of Sandwich Plates with Viscoelastic Damping Using Two-Dimensional Plate Modes

“…Then, we can nd the location that can excite up to fourth mode in each direction. This simple scheme was validatedby our experiment.To reach up to mode (1,4), the excitation location was located at .x; y/ D .265:879; 50:8/ mm [.10 5 8 ; 2/ in.] for the aluminum plate with PCLD.…”

“…4;13 A large number of modes, especially in-plane modes, were needed to achieve acceptable accuracy of frequency predictions compared to experimental data. 4 The number of assumed modes plus additional internal dissipation coordinates in the GHM method lead to a large degree-of-freedom model.…”

“…However, an effective and accurate way to solve these problems numerically is needed. In previous work, 4 the Galerkin assumed modes method was successfully applied, in conjunction with the method of Golla-Hughes-McTavish (GHM) (see Ref. 5), to the analysis of sandwich plates with isotropic face plates and a viscoelastic core using one-dimensionalbeam and rod mode shapes.…”

Free In‐Plane Vibrations of Orthotropic Rectangular Plates by Using an Accurate Solution

“…In theory, the aforementioned methods for studying transverse vibration characteristics of rectangular plates also have potential to conduct the analysis of in-plane vibration characteristics. According to the current research situation, there are relatively few related literatures on in-plane vibration characteristics of rectangular plates; the importance of which, however, has been shown in the complicated plate structures and sandwich plates [9][10][11][12][13][14][15][16]. As a matter of fact, the publications pertaining to in-plane vibrations have been increasing.…”

Dynamic properties comparisons between experimental measurements and nondeterministic numerical models of viscoelastic sandwich beams

“…Among these time-domain based methods for VEM, those that introduce extra dissipation coordinates or internal variables in order to apply the Finite Element Method (FEM), has been applied in several situations such as the ones presented by [5][6][7][8]. In this context, It is possible to observe that Golla-Hughes-McTavish (GHM) method [9,10] is frequently chosen in order to simulate the dynamic response of VEM.…”