含低速冲击损伤复合材料层合板剩余压缩强度及疲劳性能试验研究

对T300/QY8911复合材料层板进行了低速冲击、 冲击后压缩以及冲击后疲劳试验研究。通过对冲击后的层板进行目视检测和超声C扫描获得了层板受低速冲击后的若干损伤特征; 在压-压疲劳试验中, 测量了损伤的扩展情况。讨论了冲击能量与损伤面积以及冲击后剩余压缩强度的关系, 分析了含冲击损伤层合板在压缩载荷及压-压疲劳载荷下的主要破坏机制。结果表明, 低速冲击损伤对该类层板的强度和疲劳性能影响很大, 在3.75 J/mm的冲击能量下, 层板剩余压缩强度下降了65%; 在压-压疲劳载荷作用下, 其损伤扩展大致可分为两个阶段, 占整个疲劳寿命约60%的前一阶段损伤扩展较为缓慢; 而疲劳寿命的后半阶段损伤则开始加速扩展, 并导致材料破坏。

Experiment research on residual compressive strength and fatigue performance of composite laminates with low velocity impact damage

Residual compressive strength and compression-compression fatigue tests of T300/QY8911 laminates with low velocity impact damage were studied.The damage characteristic of impacted laminates was measured by visual check and ultrasonic C-scan.Damage propagation in compression-compression fatigue test was measured in detail.The relationship between damage area,compressive strength after impact(CAI) and impact energy was discussed.The major damage mechanism of damaged composites under compressive or compression-compression fatigue load was also analyzed.The results show that low velocity impact damage has a great effect on the compressive strength and fatigue performance of laminates,residual compressive strength reduces by 65% when the laminates is impacted by energy of 3.75 J/mm.The damage propagation under compression-compression fatigue load can divide in two stages,on the first 60% of fatigue life,damage grows slowly;and on the rest of fatigue life,damage has a rapid growth.