玻璃纤维增强铝合金层板低速冲击力学特性及低温影响研究

Low velocity impact performance of glass fiber-reinforced aluminum laminates and effect of exposure temperature

为研究玻璃纤维增强铝合金层板(FMLs)抗低速冲击力学特性以及受低温处理的影响,采用2A12铝合金板和单向S2-glass/epoxy预浸料制成FMLs,通过落锤低速冲击试验设备对其抗低速冲击力学特性进行研究。并采用较高冲击能量对经过-25℃和0℃低温处理1 h后的FMLs进行冲击试验,与未低温处理结果对比研究低温处理对FMLs冲击力学特性的影响。结果表明:未低温处理的FMLs在低速冲击条件下,正面铝合金铺层主要发生成坑、环向裂纹以及穿孔等损伤,背面铝合金层则发生鼓包、单向裂纹和花瓣开裂等损伤。峰值冲击载荷随着冲击能量的提高而增大,但当冲击能量达到FMLs临界穿透能后峰值冲击载荷基本保持稳定。随着冲击能量的提高,峰值位移逐渐增大,能量回弹系数逐渐减小。另一方面,低温处理可提高FMLs抗冲击性能,但会降低FMLs中铝合金/复合材料铺层界面黏结效果。处理温度越低,FMLs峰值冲击载荷越高,峰值位移越小,FMLs中复合材料和铝合金铺层发生脱胶损伤的面积越大。

In order to investigate the low velocity impact performance of fiber metal laminates （FMLs） and the effect of exposure temperature on their impact performance, a series of low velocity impact tests on FMLs made of 2A12 aluminum alloy and S2-glass/epoxy composite prepregs were conducted with drop weights. Some FMLs were then cooled at -25℃ and O℃ for one hour and impacted with higher impact energy. The experimental results showed that when FMLs without cooling are impacted at low impact velocity, denting, circumferential cracking even perforation occur in the front aluminum layer of FMLs, and bulging, linear cracking even petaling occur in the rear aluminum layer; the peak impost force increases with increase in impact energy until the impact energy reaches the perforation energy of FMLs, then the peak impact force is almost constant after perforation; the peak displacement increases with increase in impact energy but the energy restitution coefficient decreases with increase in impact energy; the low velocity impact performance of FMLs after cooled at -25℃ and 0℃ for 1 hour is improved in contrast to that without cooling but the bonding performance at the aluminum-composite interface is reduced; the peak impact force and the damage area of debonding at the aluminum- composite interface increased with decrease in exposure temperature but the peak displacement decreases with decrease in exposure temperature.