碳纤维-超高分子量聚乙烯纤维混杂增强环氧树脂复合材料低速冲击性能与失效机制  

Low-velocity impact properties and failure mechanism of carbon fiber-UHMWPE fiber hybrid reinforced epoxy resin composites

作　　者：仲越 徐铭涛 王萍 李媛媛 张岩 ZHONG Yue;XU Mingtao;WANG Ping;LI Yuanyuan;ZHANG Yan(National Engineering Laboratory for Modern Silk(Suzhou),School of Textile and Clothing Engineering,Soochow University,Suzhou 215006,China)

机构地区：[1]苏州大学纺织与服装工程学院,现代丝绸国家工程实验室(苏州),苏州215006

出　　处：《复合材料学报》2022年第7期3202-3211,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金青年项目(11802192);江苏省自然基金青年项目(BK20180244)。

摘　　要：碳纤维/环氧树脂基复合材料层合板在航天、汽车等领域应用广泛,使用中难免遇到低速冲击事件(生产使用过程中工具坠落等)产生安全隐患,分层破坏是其受到低速冲击后的主要损伤形式,会严重影响复合材料层合板的强度和使用寿命。为提高其抗冲击性能,通过短纤维增韧的方式探究超高分子量聚乙烯短纤维的铺层数量和铺层位置对复合材料层合板低速冲击性能的影响。研究结果表明:添加6层短纤维的复合材料层合板最大载荷由3.19 kN增加到4.86 kN,吸收能量由18.27 J增加到28.89 J,分别提高了52.3%和58.12%。冲击后剩余强度明显提高,两层短纤维铺层增韧方式的复合材料层合板冲击后剩余强度最大,为164.73 MPa,相比原样提高95%。超高分子量聚乙烯短纤维加入后复合材料层合板的冲击损伤阻抗提高,冲击后的凹痕深度下降,并且抗分层能力提升。其增韧机制是断裂面表面能增加,冲击使部分纤维被拔出,出现纤维桥联现象,拔出的纤维会降低分层前沿的应力集中,增大分层扩展的阻力,使分层破坏在扩展过程中需要消耗更多的能量,有效阻碍了裂纹的传播。Carbon fiber/epoxy matrix composite laminates are widely used in aerospace automobile and other fields. It is inevitable to encounter low-speed impact events(falling of tools during production and use) in use, resulting in potential safety hazards. Delamination damage is the main damage form after low-speed impact, which will seriously affect the strength and service life of composite laminates. In order to improve its impact resistance,the toughness effect of ultra-high molecular weight polyethylene(UHMWPE) short fiber on the low-velocity impact behavior of composite laminates was studied. Both toughness fiber number and position were investigated. The results show that the maximum load and absorbed energy of composite laminates with 6 short fiber layers increase from 3.19 kN to 4.86 kN and 18.27 J to 28.89 J, ultimately increasing by 52.3% and 58.12% than the virgin laminates,respectively. The residual strength(164.73 MPa) of the modified composite laminates with 2 layers is the highest,which is 95% higher than the original laminates. Both impact damage resistance and delamination resistance of the modified composites are improved, while the dent depths after impact decrease. The toughening mechanism is that the surface energy of the fracture surface increases, and the impact pulls out some fibers, resulting in fiber bridging phenomenon. The pulled out fibers will reduce the stress concentration at the front of delamination, increase the resistance of delamination propagation, make the delamination failure consume more energy in the propagation process, and effectively hinder the propagation of crack.

关 键 词：碳纤维/环氧树脂基复合材料 层间增韧 超高分子量聚乙烯(UHMWPE) 低速冲击 失效机制 

分 类 号：TB332[一般工业技术—材料科学与工程]