FREQUENCY RESPONSE ANALYSIS OF HIGHER ORDER COMPOSITE SANDWICH BEAMS WITH VISCOELASTIC CORE

In this paper, the Hamilton's principle is implemented to derive the coupled partial differential equations of motion of composite sandwich beams with viscoelastic core. The sandwich beams model is based on the higher order theory for composite sandwich beams with viscoelastic core, which regards independent transverse displacements for the face sheets with linear variations along the depth of the core. The core Young's modulus and the beam rotary inertia effects are also taken into account. Frequency response analysis is examined by applying the Galerkin discretization approach on the adimensional equations of motion. The results are validated by comparison with the existing literature. An interesting study is managed for the frequency response sensitivity analysis to the core shear modulus variation. The novelty of this work, besides the study of the fiber angle effects on the frequency response, is finding more logical relationships for regarding or discarding the core Young's modulus and the beam rotary inertia contributions, during the frequency response analysis of the beam. The results indicate the significant role of the core Young's modulus and the beam rotary inertia effects on the frequency response of the beam. The outcomes illustrate regarding the core Young's modulus, contribution hardens the structure while consideration of the beam rotary inertia softens the structure.