Search

The free vibration and buckling behaviors of foam-filled composite corrugated sandwich plates under thermal loading are investigated theoretically. A refined shear deformation theory is extended incorporating two different combinations of hyperbolic and parabolic shear shape functions. Equivalent thermoelastic properties of the foam-filled corrugation are obtained using the method of homogenization based on the Gibbs free energy. Based on hyperbolic-polynomial variation of all displacements across the thickness of both face sheets and sandwich core, the shear plate theory accounts for both transverse shear and thickness stretching effects. The theoretical predictions are validated against existing results as well as finite element simulations. The effects of geometric and material parameters on natural frequency and critical temperature change for buckling are systematically investigated. The proposed theory is not only accurate but also simple in predicting the free vibration and thermal buckling responses of composite sandwich plates with foam-filled corrugated cores.

A novel lightweight sandwich construction with honeycomb–corrugation hybrid core is fabricated by filling the interstices of aluminum corrugations with trapezoidal aluminum honeycomb blocks. The performance of the hybrid structure under quasi-static out-of-plane uniform compression is investigated, both experimentally and theoretically. When all the interfaces in the hybrid structure are fixed using epoxy glue, the proposed structure is found to have strength and energy absorption capacity significantly greater than the sum of those of empty corrugated sandwich and honeycomb-cored sandwich. It is demonstrated that the interaction effect between honeycomb insertions and corrugated plates stabilizes buckling and changes the crushing deformation mechanisms of both constituents, leading to enhanced strength and energy absorption. Comparison with competing lightweight sandwich constructions having equal mass reveals that the proposed hybrid structure exhibits superiority in both strength and energy absorption in the low-density regime. Keywords: Honeycomb–corrugation hybrid, Strength, Energy absorption, Finite element analysis

A combined analytical and numerical study is carried out for the structural stiffness, collapse strength and minimum mass design of foam-filled corrugated sandwich beams under transverse three-point bending. Both close-celled aluminum foam and polymer foam as the filling material are considered. Based upon a micromechanics-based model, effective elastic constants of foam-filled corrugations are derived using the homogenization method. To analytically predict the initial collapse strength, six different failure modes are considered, with the effect of loading platen width accounted for. Finite element simulations are performed to validate the analytical predictions, with good agreement achieved. Minimum mass design is obtained as a function of structural strength, and the influence of foam material and loading platen width is quantified. The structural efficiency of foam filling to reinforce the sandwich is assessed on the basis of equal mass and the underlying mechanisms explored. It is shown that polymer foam-filled corrugations are more weight efficient than unfilled ones of equal mass.