不同等级损伤复合材料层压板的压缩失效行为

Compression Failure Behavior of Composite Laminates with Low-velocity Impact Damage

研究了目视不可检与可检损伤对CF3052/5224复合材料层压板冲击后压缩失效行为的影响。对复合材料进行了低速冲击和冲击后压缩试验,采用超声C扫描、宏观断口观察等手段将两种损伤等级试样的失效模式进行了对比,同时分析了冲击凹坑深度随冲击能量变化中存在拐点的现象。结果表明:目视不可检损伤层压板主要是基体开裂和分层,目视可检损伤层压板除基体开裂和分层严重外,还存在大量的纤维断裂;两种等级损伤层压板在冲击损伤中心区域的侧面断口上可见由冲击造成的微屈曲失效特征,冲击损伤边缘未受冲击影响,其失效模式与无损伤层压板失效模式相同,均为剪切分层失效。

The effect of visually-undetected and detected damages on the compression failure behavior of CF3052/5224 composite laminates after impact was studied.Low-velocity impact and compression tests were carried out on the composite laminates.The failure modes of the composite laminates with the two type damages were compared.And the knee point in the relationship curve of the impacted pit depth with impaction energy variation was analyzed.The results show that the main failure mode of the composite laminates with visually-undetected damage is crack and delamination of the matrix.However,the composite laminates with visually-detected damage,besides crack and delaminating of the matrix,fiber fracture is seen.The micro buckling feature caused by impacting exists at the side fracture surface of the impaction damage central region,and the brim of the impaction damage region is not affected.The failure mode of the composite laminates with damage is a shearing and delaminating failure,the same as the undamaged composite laminates.