Nonlinearities in the deformation of composite sandwich beams

E. E. Gdoutos, Isaac M Daniel

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

An investigation was conducted on the nonlinear behavior of composite sandwich beams made of unidirectional carbon/epoxy facings and PVC foam cores under bending. The carbon/epoxy after an initial linear response exhibits a stiffening nonlinearity in tension and a softening nonlinearity in compression with the longitudinal strength in tension higher than that in compression. This implies that the neutral axis of sandwich beams under bending does not pass through the centroid of the cross section, but is displaced toward the tensile side of the beam. A simple equation was derived and used in conjunction with the stress-strain behavior of the facing material in tension and compression to determine the position of the neutral axis of the beam. Experimental results by moire measurements of the in-plane horizontal displacements of the core material corroborated the analytical predictions. These findings imply higher compressive and smaller tensile stresses in the core. The variation of the normal stresses along the height of the beam is nonlinear and should to be calculated by taking into consideration the nonlinear stress-strain behavior of the core material in tension and compression.

Original languageEnglish (US)
Title of host publicationSociety for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
Pages1662-1668
Number of pages7
StatePublished - Dec 1 2008
Event11th International Congress and Exhibition on Experimental and Applied Mechanics 2008 - Orlando, FL, United States
Duration: Jun 2 2008Jun 5 2008

Publication series

NameSociety for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
Volume3

Other

Other11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
CountryUnited States
CityOrlando, FL
Period6/2/086/5/08

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials

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