Minimum mass optimization of curved grid-honeycomb sandwich panels with cutouts under buckling constraints

Frame-type stiffened structures are commonly used in engineering, the addition of the grids to the core of the sandwich panel is equivalent to adding stiffeners to the structure. The curved grids are more designable, and the load-bearing capacity can be increased through rational layout. In this paper, the curved grid-honeycomb sandwich structures with cutouts were proposed, and the optimization of the layout of the curved grids was achieved based on the minimum mass requirement under buckling constraints. A parametric model for linear buckling under uniaxial compression was established, and the parametric studies revealed that sandwich panels with curved grids had a stronger buckling resistance compared to straight grids. Combined with the Adaptive Simulated Annealing (ASA) algorithm, the layout of the curved grid was further optimal designed to solve for the minimum mass under buckling constraints, and the optimized model also included orthogonal and angle grids in engineering. The results of the optimization showed that the curved grid-honeycomb sandwich panels achieved the lightest mass, which provided the highest weight reductions of 42.76% and 24.32% compared to orthogonal and angle grids, respectively. Furthermore, the minimum number of curved grids in the optimal solution was beneficial to the manufacturing cost and structural integrity.