薄面板复合材料蜂窝夹层结构冲击穿透试验与失效机理

为研究薄面板复合材料蜂窝夹层结构冲击穿透损伤的失效机理,对具有3层平面编织复合材料面板的蜂窝夹层板试验件进行了多种能量的冲击试验.并在考虑了面板材料的渐进失效以及面内剪切非线性应力应变关系基础上,运用LS-DYNA有限元分析软件建立了夹层板的数值模型,用以分析失效过程.结果 表明,数值模拟结果与试验结果一致.上面板穿透或整体贯穿时面板均呈花瓣状裂开,前者蜂窝以压溃损伤为主,后者则额外产生蜂窝芯体与下面板间的界面脱粘以及蜂窝壁的断裂损伤.无面板穿透时,冲击接触力将保持纤维断裂损伤阈值力大小直至冲头回弹;面板穿透则使冲击区域刚度下降,接触力随之下降,其中板整体贯穿时接触力会出现两个峰值.薄面板复合材料蜂窝夹层结构冲击穿透过程中的主要能量耗散在复合材料面板的纤维拉伸断裂,蜂窝的压溃和断裂过程也消耗部分能量.

Experimental and Perforation Mechanism of Thin-facesheets Sandwich Panels Subjected to Impact Loading

In order to investigate the perforation mechanism of honeycomb sandwich panels with thin composite face-sheets subjected to impact loading, experimental tests with different impact energies were carried out in this study. Specimens with 3 plain woven plies were impacted with different values of impact energy. Numerical simulations are also carried out with the usage of LS-DYNA to analyze the failure process. The progressive failure and in-plane shear nonlinear stress-strain relationship of face-sheet are taken into consideration. The numerical results are compared well with experimental results. Face-sheet splits as petals. The honeycomb crush take place when the top face-sheet is perforated while the interfacial debonding between the honeycomb core and bottom face-sheet and the honeycomb fracture take place when the whole panel is perforated. The contact force will remain the threshold load of fiber fracture until impactor spring back without perforation occurring. Two wave crest emerge on the contact force curve when the whole panel perforated. The reason of face-sheet perforated is fiber fracture damage appearing in petal root. The tensile strength of face-sheet contribute a lot to the perforation resistance of sandwich panels.