Optimum design of honeycomb sandwich constructions with buckling constraints

Optimum design of honeycomb sandwich constructions with buckling constraints is treated in this paper. Four modes of instability for honeycomb sandwich structures are considered in buckling constraints, including overall buckling, core shear instability, face wrinkling, and monocell buckling. The face thicknesses, core depth, cell wall thickness, and diameter of an inscribed circle in a honeycomb cell are taken as design variables. Eight-nodal quadrilateral honeycomb sandwich isoparametric shell elements and hybrid approximation techniques in combination with the dual solution are used. Some comparisons are also made between the cases with and without buckling constraints. Numerical results are given for four examples.