摘要
采用真空辅助传递模塑(VARTM)工艺制备了铺层为[45°/-45°/0°/90°]2s的缝合/未缝合泡沫夹芯结构复合材料,并在15 J的冲击能量下对其进行了五种不同冲击次数的落锤反复低速冲击实验,通过Micro-CT扫描对冲击后的纤维面板内部不可见的损伤进行表征,从而揭示其内部损伤机理。结果表明:泡沫夹芯结构复合材料损伤形式主要包括分层损伤、基体开裂和纤维断裂。经历前五次冲击后,泡沫夹芯结构复合材料主要产生分层损伤和基体开裂,纤维断裂仅出现在冲击位置;随着冲击次数的增加,纤维断裂的现象愈加明显。面板层间损伤从冲击表面至材料内部的主要损伤模式不同,其损伤面积呈递增状,靠近泡沫的第7—8层的层间分层所带来的损伤面积最大。缝线树脂柱能够有效改善泡沫夹芯结构的抗冲击性能,与未缝合相比,缝合泡沫夹芯复合材料在相同冲击次数下的残余最大冲击载荷的提升幅度为33.4%~48.1%。此外,还得到了15 J能量下冲击次数及凹坑深度的关系曲线图,并拟合出相应的数学公式,再结合曲线拐点位置,能够实现对复合材料损伤模式的预测。
The stitched/unstitched foam sandwich structures with a layer of[45°/-45°/0°/90°]_(2s) were prepared by the vacuum assisted transfer molding(VARTM)process.Subsequently,five repeated low-velocity impact experiments with different falling hammer impact times were carried out on them under the impact energy of 15 J,and then the invisible damage inside the fiber panel after impact was characterized by Micro-CT scanning,thus revealing the internal damage mechanism.The results show that the damage patterns of foam sandwich composite materials mainly include delamination damage,matrix cracking and fiber fracture.After the first five impacts,the foam sandwich structure composite material mainly produces delamination damage and matrix cracking,and the fiber fracture only appeares at the impact position;with the increase in the number of impacts,fiber fractures become more serious.The main damage pattern of the interlayer damage of the panel is different from the impact surface to the inside of the material;the damage area is increasing and the damage area of the 7th to 8th interlayer delamination close to the foam is the largest.In addition,the stitch resin column can effectively improve the impact resistance of the foam sandwich structure.Compared with unstitched,the residual max impact force of the stitched foam sandwich composite material with the same impact times can be increased by 33.4%—48.1%.The relationship curve between the number of impacts and the depth of the pit under 15 J energy is obtained,and the corresponding mathematical formula is fitted.With the inflection point position of the curve combined,the damage pattern of composite material can be predicted.
作者
罗志强
赖家美
黄志超
莫明智
李美艳
LUO Zhiqiang;LAI Jiamei;HUANG Zhichao;MO Mingzhi;LI Meiyan(Polymer Processing Research Lab,Nanchang University,Nanchang 330031,China;Key Laboratory for Conveyance and Equipment of the Ministry of Education,East China Jiao Tong University,Nanchang 330013,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第19期214-221,共8页
Materials Reports
基金
国家自然科学基金(51763016,51875201)。
关键词
泡沫夹芯结构
反复冲击性能
CT扫描
损伤机理
拐点
foam sandwich structure
repeated impact performance
CT scanning
damage mechanism
inflection point
作者简介
罗志强,2019年9月至2022年6月硕士就读于南昌大学,主要从事聚合物成型方面的研究;赖家美,南昌大学机电工程学院副教授。2004年毕业于南昌大学,获得材料加工工程专业博士学位。主要从事聚合物基复合材料制备和性能研究,主持国家自然科学基金2项、江西省青年科学家培养对象计划项目1项、省(部)级科研项目3项等,发表EI论文10余篇。laijm@163.com。
