Effects of Ply Stacking Sequence in 3D Fiber Reinforced Foam Core Sandwich Structures with Defects

Foam core sandwich composites are widely used in primary structural components of launch vehicles and spacecraft. These structures exhibit complex failure modes and are highly sensitive to butt-joints, core mismatches, impact damage, voids, and facesheet delaminations. 3D Fiber Reinforced Foam Cores (3DFRFC) represent a new class of core material designed to replace standard foam core in future aerospace structures. An analysis program is being developed to investigate the effect of ply stacking sequence on debond buckling in 3DFRFC structures with defects. The detailed microstructure is modeled using the embedded element method to investigate the local interaction between the facesheet and the core. Linear and nonlinear buckling analysis was used to understand the sensitivity of the predicted buckling load to the ply stacking sequence. Preliminary results show that the effect of ply stacking sequence on the buckling load is consistent across variations to the core types, modeling methods, and defect sizes investigated.