小当量近场爆炸冲击下CFRP层合板失效机理及吸能特性

Failure Mechanism and Energy Absorption Characteristic of CFRP Laminates under Small⁃quantity and Near⁃field Blast Loading

为研究碳纤维增强环氧树脂基复合材料(Carbon Fiber Reinforced Polymer,CFRP)在小当量近场爆炸冲击下的失效机理及吸能特性,对CFRP层合板分别开展了自由场爆炸试验和扫描电镜试验。同时,建立采用3D Hashin失效准则的复合材料层合板损伤模型,针对近场爆炸冲击下CFRP层合板的动响应行为进行了数值模拟,结合试验结果分析了CFRP层合板在近场爆炸冲击下的失效机理及吸能特性。结果表明:CFRP层合板迎爆面与背爆面失效模式存在差异,层合板迎爆面受到冲击波直接作用,出现基体开裂、纤维断裂或中心穿孔失效,分层出现在纤维⁃基体界面;背爆面由于反射拉伸波的作用,出现大面积的分层失效与裂片飞出,分层出现在基体内部。在层合板动响应过程中,高应力区域集中在穿孔区域边界,沿纤维方向分布,0°与90°铺层的应力水平高于±45°铺层。与迎爆面相比,背爆面处的层合板吸收转化大部分能量,约占总吸能的52%~56%。

To study the failure mechanism and energy absorption of carbon fiber reinforced polymer(CFRP)composites subject⁃ed to small⁃quantity and near⁃field blast loading,free⁃field blast tests and scanning electron microscope(SEM)tests were carried out on CFRP laminates.Meanwhile,a damage model was established based on the 3D Hashin failure criterion,and the dynamic response of CFRP laminates under near⁃field blast loading were simulated.Combined with the test results,the failure mechanism and energy absorption of CFRP laminates were analyzed.Results show that there are differences in the failure modes between the facing and back blast surfaces of CFRP laminates.The matrix cracking,fiber fracture or center perforation mainly appear on the facing blast surface,and the delamination occurs at the fiber⁃matrix interface.The large⁃area delamination failure and the frag⁃ment dispersion of the back blast surface are mainly due to the influence of the reflected tension wave,and the delamination of appears inside the matrix.During the response process of laminates,the high stress area is concentrated on the boundary of the center perforation and distributed along the fiber direction,and the stress levels of 0°ply and 90°ply are larger than that of±45°ply.Compared with the facing blast surface of laminates,the layers of the back blast surface absorb and transform large energy,accounting for 52%-56%of the total energy absorption.