Kevlar短纤维增韧碳纤维/铝蜂窝夹芯板三点弯曲与面内压缩性能

Three-point bending and in-plane compression properties of carbon-fiber/aluminum-honeycomb sandwich panels with short-Kevlar-fiber toughening

介绍了碳纤维/铝蜂窝夹芯结构的Kevlar短纤维界面增韧方法。通过三点弯曲实验和面内压缩实验,对比增韧试件与未增韧试件的载荷位移曲线、破坏模式等特征,发现未增韧试件往往先发生界面分层破坏,继而面板和芯体分别发生局部破坏;而增韧试件通常发生整体破坏。实验数据显示,Kevlar短纤维界面增韧可以使碳纤维/铝蜂窝夹芯板的抗弯强度、压缩强度、能量吸收等力学性能分别至少提高14.06%、55.80%和61.53%。对破坏后界面的SEM观测发现:增韧试件并未发生界面脱粘,而是由于芯体撕裂造成面/芯剥离,揭示了Kevlar短纤维的界面增韧机制。对具有Kevlar短纤维界面增韧的碳纤维/铝蜂窝夹芯结构进行有限元建模,并分别对其在三点弯曲和面内压缩载荷下的力学行为进行数值分析,以指导该类夹芯结构的分析与设计。

The short-Kevlar-fiber toughening method for carbon-fiber/aluminum-honeycomb sandwich panels was introduced.Three-point bending tests and in-plane compression tests were conducted.The load-displacement curves and failure modes were compared for toughened specimens and non-toughened specimens,which indicated that interface debonding followed by local failures occurred on the non-toughened specimens,whereas the toughened specimens behaved global failure with structural integrity.The results demonstrate that the bending property,compressive property and energy absorption of the carbon fiber/aluminum honeycomb sandwich panels are respectively increased by more than 14%,55% and 61% by the short Kevlar fiber toughening.The observations of the damaged interface by SEM reveal that the toughened interface is kept bonded,while the face-core separation of the toughened specimen is caused by the fracture of honeycomb core.The FEM modeling was conducted to numerically analyze the three-point bending and in-plane compression performance of carbon fiber/aluminum honeycomb sandwich structures with and without short Kevlar fiber toughening.The FEM results provide general guidance for the designing of such sandwich structures.