Modal characteristics of micro-perforated sandwich beams with square honeycomb-corrugation hybrid cores: A mixed experimental-numerical study.

Abstract Modal performance of micro-perforated sandwich beams with honeycomb-corrugation hybrid cores was investigated. Finite element methods and modal analysis techniques have been used to predict their vibration characteristics (i.e. their natural frequencies and mode shapes). It is shown that the natural frequencies of sandwich beam with micro-perforation are slightly lower than those of corresponding order of sandwich beam without micro-perforation based on the experimental and three-dimensional finite element calculated results. To reveal the effect of micro-perforation diameters on the natural frequencies of sandwich beams, a dimensionless frequency parameter ϖ was proposed. The results demonstrate that the frequency parameter of sandwich panels decrease near-linearly with the increase of micro-perforation ratio. In addition, the frequency parameter ϖ is sensitive not to such parameters as the face sheet thickness ratio, the slenderness ratio of corrugated member and the relative density of filling honeycomb, but to the configuration of micro-perforation. Highlights • Novel lightweight sandwich constructions with micro-perforated square honeycomb-corrugation hybrid cores are proposed. • Natural frequencies increase with the facesheet thickness and filling honeycomb, decrease with the corrugation thickness. • Frequency parameter of sandwich panels decrease near-linearly with the increase of micro-perforation ratio. • Frequency parameter is not sensitive to geometry parameters, however, to the configuration of micro-perforation. [ABSTRACT FROM AUTHOR]