Implementation of Third Order Plate Theory for use in Existing Finite Element Software

Sandwich plates and layered composites are common in many structural applications because of their combination of high stiffness and low weight. These plates combine top and bottom layers of high Young's modulus with intermediate layers of material carrying predominantly shear loads. Finite elements developed for the analysis of sandwich plates need to accurately model transverse shear stresses through the plate thickness. This study was inspired by an Office of Naval Research project to investigate the suitability of steel sandwich plates as ship hulls. A finite element implementation based on a third-order shear deformation element was used in a standard finite element program to model transverse shear stresses in a simply supported plate. Four elements based on third-order theory are developed and tested. Using static condensation to reduce the number of degrees of freedom required by a third-order plate element does not preserve the element's accuracy in either displacements or stresses, and stresses do not converge with refinement of the mesh. For the thin isotropic plate case, some condensed elements give reasonable displacement and stress results, but only for certain choices of mesh and the element is less versatile than one based on first order plate theory. None of the condensed elements give good results for composite plates of any thickness.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Aerospace and Ocean Engineering

Department dc:contributor.department

Aerospace and Ocean Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2006

Author dc:creator

• Portier, Sarah

Chair dc:contributor.committeechair

• Kapania, Rakesh K.

Committee members dc:contributor.committeemember

• Hughes, Owen F.
• Patil, Mayuresh J.

• Static Condensation
• Finite element method
• Third Order Plate Theory
• Plate Element

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Dc Identifier Other

etd-05192006-093252

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/79680