Nonlinear finite element analysis of lattice core sandwich plates

Praneeth Nampally, Anssi T. Karttunen*, J. N. Reddy

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

14 Citations (Scopus)


A displacement-based, geometrically nonlinear finite element model is developed for lattice core sandwich panels modeled as 2-D equivalent single-layer (ESL), first-order shear deformation theory (FSDT) micropolar plates. The nonlinearity is due to the moderate macrorotations of the plate which are modeled by including the von Karman nonlinear strains in the micropolar strain measures. Weak-form Galerkin formulation with linear Lagrange interpolations is used to develop the displacement finite element model. Selective reduced integration is used to eliminate shear locking and membrane locking. The novel finite element model is used to study the nonlinear bending and linear free vibrations of web-core and pyramid core sandwich panels. Clamped and free edge boundary conditions are considered for the first time for the 2-D micropolar ESL-FSDT plate theory. The present 2-D finite element results are in good agreement with the corresponding detailed 3-D FE results for the lattice core sandwich panels. The 2-D element provides computationally cost-effective solutions; in a nonlinear bending example, the number of elements required for the 2-D micropolar plate is of the order 10(3) , whereas for the corresponding 3-D model the order is 10(5) .

Original languageEnglish
Article number103423
Number of pages12
Publication statusPublished - May 2020
MoE publication typeA1 Journal article-refereed


  • Constitutive modeling
  • Finite element
  • Geometric nonlinearity
  • Lattice material
  • Micropolar plates
  • Natural frequencies
  • Nonlinear bending


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