复合材料桨叶典型铺层低速冲击后静力及疲劳性能试验研究

Post-impact static and fatigue properties of typical skins of helicopter composite blade

  • 摘要: 为了研究直升机复合材料桨叶典型铺层的低速冲击力学性能,开展了典型混合铺层EW250F(0/90)/CF3052(45/−45)3/CF3052(0/90)层合板落锤式低速冲击试验,测定了低速冲击响应曲线,通过凹坑深度和损伤面积研究了该层合板的低速冲击损伤特性,分析了损伤模式和机理;对低速冲击后层板进行了准静态拉伸试验和拉-拉疲劳试验,测定了冲击后层板的拉伸剩余强度、剩余模量和疲劳极限强度。试验结果表明,(1)当冲击能量为2.9 J和3.6 J时,试样的主要损伤模式为分层和基体开裂,残余挠度几乎为零,能量吸收能力变化不大,拉伸剩余强度显著下降,剩余模量仅略有下降;(2)冲击能量为7.2 J和9.0 J时,纤维断裂成为主要损伤模式,残余挠度显著增大,能量吸收能力显著提高,拉伸剩余强度略有下降,而拉伸剩余模量显著下降;(3)冲击后拉-拉疲劳的主要失效模式为分层损伤和纤维断裂,疲劳极限随冲击能量的增加而显著降低,且玻璃纤维与碳纤维层界面性能差异是分层损伤的主要原因。

     

    Abstract: To investigate the low-velocity impact mechanical properties of typical layups in helicopter composite rotor blades, low-velocity impact tests were conducted on a typical hybrid layup EW250F(0/90)/CF3052(45/−45)3/CF3052(0/90) laminate using a drop-weight apparatus. The low-velocity impact response curves were measured, and the damage characteristics were analyzed through dent depth, damage area, damage modes, and failure mechanisms. Quasi-static tensile tests and tension-tension fatigue tests were subsequently performed on the impacted laminates to determine their post-impact tensile residual strength, residual modulus, and fatigue limit strength. The experimental results revealed that: (1) At impact energies of 2.9 J and 3.6 J, the primary damage modes were delamination and matrix cracking. Residual deflection remained nearly negligible, with minimal variation in energy absorption capacity. However, the tensile residual strength exhibited a significant reduction, while the residual modulus showed only a slight decrease. (2) At impact energies of 7.2 J and 9.0 J, fiber breakage became the dominant damage mode. A pronounced increase in residual deflection and energy absorption capacity was observed. The tensile residual strength decreased marginally, whereas the tensile residual modulus declined substantially. (3) The primary failure modes during post-impact tension-tension fatigue were delamination and fiber breakage. The fatigue limit decreased significantly with increasing impact energy. The interfacial performance disparity between glass fiber and carbon fiber layers was identified as the primary cause of delamination damage.

     

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