New Formulation for Composite Sandwich Shell Finite Element

Sandwich shell finite element formulation is developed and presented. The sandwich shell element formulation allows for orthotropic faces and core material. The sandwich shell element is based on first shell order shear deformable theory utilized by most shell finite elements for isotropic materials. Consequently, the presented procedure can be adopted for any shell element available in commercial finite element packages. The formulation is based on the equalities of stress and moment resultants between a sandwich shell element and a typical homogenous shell element. The developed element is implemented in the nonlinear finite element code DYNA3D to validate and check its accuracy, efficiency and overall performance. The predicted results show good agreement with results obtained from far more complicated and computationally intensive 3-D analyses.