Bending Optimization of Composite Sandwich Panels with Second-Order Corrugated Cores

Second-order corrugated cores are one type of hierarchical cores that use the common corrugated cores as constituent elements for the main core. This paper attempts to identify and optimize the bending properties of composite sandwich panels with second-order corrugated core. To this end, both first- and second-order corrugated cores are constructed and force-displacement diagrams are extracted in three-point bending tests. Finite element models are created and the deflection results are validated by experiments. Based on the Taguchi method, various finite element models with different geometrical parameters are modeled and reaction force and stiffness are determined. Stiffness formulas for first- and second-order corrugated cores are determined by using regression analysis. The constrained-optimization results are determined to optimize the stiffness of sandwich panels with first- and second-order corrugated cores, separately. The global optimization problem is implemented to compare the first- and second-order configurations.