543 面外集中荷重を受けるフォームコアサンドイッチ梁の損傷挙動(高分子/高分子基複合材料(5),ものづくりにおける基礎研究と先端技術の融合)

Abstract

Foam core sandwich structures are integral constructions consisting of two composite facesheets and a lightweight foam core. Since they have excellent mechanical properties, application of foam core sandwich structures to primary aircraft structures is highly expected. However, since the composite facesheet is very thin and the lightweight foam core is weak, they can be easily damaged when an impact or indentation load is applied. The facesheet locally deflects and the core is crushed. A residual dent induced by the core crushing significantly degrades the mechanical properties of the foam core sandwich structure. However, underlying mechanism of the residual dent formation is not sufficiently clarified. This study investigated quasi-static indentation response of foam core sandwich beams. First, the indentation loading-unloading response and the subsequent relaxation behavior were evaluated using quasi-static indentation tests. The indentation behavior was then analyzed by extending a "segment-wise model", which was formulated for honeycomb sandwich beams in a previous study. It was shown that the reaction force from the core to the facesheet controls the residual dent formation and that the relaxation behavior of the facesheet dent can be predicted by considering the stress relaxation of the crushed core.