多损伤复合材料加筋壁板高周疲劳特性及剩余压缩强度

为研究常用于飞机垂尾的复合材料加筋壁板的冲击疲劳特性,设计了该型加筋壁板多点冲击试验、高周疲劳试验及剩余压缩强度试验。讨论了不同冲击能量对筋条边缘冲击损伤的影响,及施加低应力水平的疲劳载荷后各冲击损伤区域的扩展情况,对比分析了疲劳对冲击后剩余压缩强度的影响。结果表明:40J能量冲击后的损伤面积和凹坑深度较大,C扫描损伤形貌很不规则。100万次低应力疲劳后主损伤区附近衍生出新损伤,导致压缩破坏时产生向上、下夹具扩展的裂痕。该型加筋壁板疲劳后破坏载荷保持率为95.6%,有较好的抗冲击疲劳能力,为加筋壁板耐久性及后屈曲设计提供了思路。

High cycle fatigue characteristics and residual compressive strength of composite stiffened panels with multi-damage

To study the impact and fatigue properties of composite stiffened panels, which are widely used in aircraft vertical tail, the multi-impact, high cycle fatigue and residual compressive strength tests were designed based on the composite stiffened panels. The effects of different impact energy on impact damage of stiffener edge were discussed, and damage area development condition under fatigue load of low stress level was also studied. The effect of fatigue on residual compressive strength after impact was given. Results show that the damage areas and dent depth of 40 J impact energy are large, and the damage morphologies of C-scan test are more irregular. The new damage is promoted from main damage area after one million low stress fatigue, and the crack induced by compression failure is propagated to the top and bottom fixed jig. The stiffened panels exhibit better impact and fatigue damage resistance since the retention rate of breaking load after fatigue is about 95.6%. The results can be used for durability and postbuckling design of stiffened panels.