An improved higher order zigzag theory for the static analysis of laminated sandwich plate with soft core

An improved higher order zigzag theory is proposed for the static analysis of laminated sandwich plate with soft compressible core. The variation of in-plane displacements is assumed to be cubic for both the face sheets and the core and transverse displacement is assumed to vary quadratically within the core while it remains constant through the faces. The core is considered to behave as a three-dimensional elastic medium to incorporate the effect of transverse normal deformation. A computationally efficient C0C0 finite element is also proposed for this model. Numerical examples of laminated composite and sandwich plate are provided for different thickness ratios and aspect ratio to illustrate the accuracy of the present formulation by comparing the present results with the three-dimensional elasticity solutions. Some new results are also presented. The performance of the present model is excellent in calculating displacements and stresses for a wide range of sandwich plate problems with transversely flexible core.