碳纤维/环氧树脂复合材料在爆炸冲击下的微损伤分析

Damage in carbon fiber/epoxy resin composites under explosive impact

采用光学显微镜和 JEM- 6 30 1F场发射扫描电镜 ,观察了多向编织碳纤维 /环氧树脂复合材料在不同载荷下的断口和微损伤形貌 ,并分析其破坏形式和损伤过程。目的是为复合材料的结构设计和制造提供依据。实验结果表明 :低速加载下断裂过程依赖于应力的传递特性 ,表现为脆断 ,纤维断裂主要是由纤维表面缺陷引起的。在爆炸冲击下 ,试件碎裂区纤维呈现出剪切断裂和脱粘拔出 ,纤维间树脂呈层状或河流状花样 ;爆炸产生的复杂应力将首先择优作用于编织束界面上 。

The changes in the mechanical properties resulting from damage to carbon fiber/epoxy resin composites resulting from explosive impact were studied by optical microscope and field emission gun scanning electron microscope (SEM). The results show that the fracture morphology of the material varied with loading rate and the fracture process depends on the stress transfer behavior. The material exhibited brillte fracture characteristics which originated from the plastic constraints of the fiber. Fiber fracture was caused by defects on the surface of the carbon fibers at low loading rate. An explosive impact test, carried out in a special attachment, showed that the material had superior energy absorption capability and damage tolerance. Analysis of the fracture process showed that the damage included sheared fibers and epoxy flaking off under the ablation region. The propagation path of the macro crack is mainly in the braided sheaf and along the sheaf interface under the ablation region.