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ABSTRACT Auxetic foam is a new material that exhibits a negative Poisson' s ratio. It gets fatter when stretched and thinner when compressed. This property results from its re-entrant cell shape. Auxetic foam has been fabricated by heating and compressing to force the cell rib into permanent buckle and deformation, and then the cells were converted from converx shape to re-entrant shape. The Poisson's ratio is such a important property of a material that a negative Poisson's ratio will significantly affect the material's mechanical performance . The new material here is the core of composite sandwich plates, and a finite element method is developed to analysis the dynamic performance of the plates with low velocity impacted. We will discuss the difference of contact force, displacement, and strain between composite sandwich plates with auxetic foam and usual foam . The method we developed is using finite element method to model the face plate that based on the Mindlin's plate theory and lamination theory. A nine-node isoparametric element is employed in the finite element programming. The displacement fields of the sandwich core are linearly interpolated in terms of the displacements of two face plates
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