碳/芳纶混杂纤维增强波纹夹芯结构低速冲击性能

Low-velocity impact properties of carbon/aramid hybrid fiber reinforced corrugated sandwich structure

采用碳纤维和芳纶纤维增强复合材料对波纹夹芯结构的面板进行层间混杂铺层设计,通过真空辅助树脂灌注(VARI)成型工艺制备混杂波纹夹芯结构。在60 J、80 J和100 J三种不同冲击能量下,研究了面板混杂铺层方式对波纹夹芯结构低速冲击性能及冲击后压缩强度的影响,并利用超声C扫和工业CT断层成像两种无损检测技术对波纹夹芯结构的冲击损伤机制进行了分析。结果表明:冲击能量较低时,波纹夹芯结构的吸收能量基本不受面板的混杂铺层方式影响,而凹坑深度随表层碳纤维层数增加而减少。冲击能量较高时,面板为分层式混杂(碳/芳纶纤维单层交替铺层)的波纹夹芯结构的抗冲击性能最好,纤维断裂损伤和层间分层主要发生在试样表层,但损伤面积较大;面板为夹层式混杂(以碳纤维为蒙皮、芳纶纤维为芯材)的波纹夹芯结构具有较高的吸收能量,整个上面板的纤维都发生了断裂破坏,但损伤面积较小。碳/芳纶混杂波纹夹芯结构的面板采用分层式和夹层式的混杂铺层设计时,具有较高的冲击后压缩强度。

The carbon/aramid hybrid fiber reinforced composite laminates were used here as skins to design corrugated sandwich structures,which were fabricated by vacuum assisted resin infusion(VARI)process.Low-speed impact tests were conducted by three levels of energy,60 J,80 J and 100 J,and compression after impact tests were then carried out on these structures.Later,non-destructive testing techniques,including ultrasonic C-scan and industrial CT tomography,were applied to analyze the damage mechanism.The effects of hybrid modes on the lowspeed impact properties and post-impact residual compression strength of the structures were investigated.The results show that at lower impact energy,the energy absorption of the corrugated sandwich structures is basically not affected by the fiber stacking sequence of the skins,but the dent depth decreases with the increase of carbonfiber layers on the surface.By increasing the impact energy,the corrugated sandwich structure with inter-layer hybrid skins exhibits better impact performance because fiber fracture and interlayer delamination mainly occur between the external layers but larger damage area.On the other hand,the corrugated sandwich structure with sandwich-like hybrid skins can absorb more energy by penetration of the skins in small area.In conclusion,better post-impact compression capacity can be achieved for carbon/aramid hybrid fiber reinforced corrugated sandwich structures by the adoption of inter-layer or sandwich-like hybrid skin designs.