基于内联三维网络复合材料自修复实验及数值模拟

Experiment and numerical simulation of composites with interconnected three dimensional mendable polymer networks

通过用热塑性树脂纤维EMAA将铺层好的预浸料沿厚度方向进行缝合及平面方向进行编入,建立起内联三维自修复网络,固化成型之后加工成双悬臂梁(DCB)试件。根据ASTM D5528—01标准测试了试件的Ⅰ型层间断裂韧性。实验结果表明,内联自修复网络层合板的Ⅰ型层间断裂韧性比无自修复网络层合板提高了约116%,自修复后,试件断裂韧性得到很好的恢复,修复效率约为164%。同时,在基于粘聚区的界面单元法基础上,建立了模拟修复剂及树脂基体的双分区粘聚区模型,通过有限元分析方法研究了无修复剂试件、含内联自修复网络试件及自修复后试件的分层裂纹扩展过程,数值结果与实验结果基本吻合,更好地解释了含内联自修复网络试件的层间增韧及自修复机理。

Composite prepreg was stitched in the through-thickness and plane direction to create a 3D self-healing network of EMAA fibres. Then the composite laminates were cured and cut into double cantilever beam （DCB） specimens. The mode I inter- laminar fracture toughness was measured according to ASTM D5528--01 standard. The experimental results show that the stitched EMAA fibres increase the mode I interlaminar fracture toughness （by ~ 116%） of the laminate, and the laminates using mendable polymer stitching have high recovery in the delamination fracture toughness （ - 164% compared to the original material）. In addi- tion, based on the interface element method of the cohesive zone, the cohesive zone model with two partitions was established to simulate the healing agent and the epoxy resin. The propagation of cracks for the specimens was analyzed by using the finite element method including before and after self-healing. The numerical results are well in agreement with the experimental results and the toughening and self-healing mechanism of the laminates with three dimensional mendable polymer networks is explained by numeri- cal analysis.