摘 要:随着纤维增强复合材料的广泛应用,研究其在湿热环境下的动态力学性能具有重要的理论研究意义与工程应用价值。本文首先对碳纤维增强环氧树脂基(Carbon/Epoxy)复合材料层合板试件进行了湿热处理,其后采用分离式霍普金森压杆(SHPB)技术开展了干/湿态试件高应变率压缩实验并对实验结果进行分析。研究结果表明:材料脱(吸)湿过程呈现出两段式特点,存在“二次脱(吸)水”现象;Carbon/Epoxy层合板的强度在垂直铺层方向具有显著的应变率敏感性,随着应变率从1500s-1增加至6000s-1,其强度增加近三倍,与此同时应变率对其弹性模量的影响却非常微弱;此外,湿热处理有助于提升该种材料的动态力学性能,经20天吸湿后材料动态强度有最大12.45%的增幅,吸湿引致材料动态强度的上升在应变率较低时比较明显。
关键词:碳纤维增强复合材料;湿热环境;高应变率;动态压缩;SHPB
Abstract: With the extensive application of fiber reinforced composite, the study on its compression property under hygrothermal environment therefore is provided with theory research significance and practical application value. In this paper, the impact mechanical performances of carbon fiber reinforced resin matrix (Carbon/Epoxy) composite laminates under the condition of hygrothermal and high strain rate were investigated using split hopkinson pressure bar (SHPB). First, both hygrothermal treated specimens and dry specimens were prepared. And then impact mechanical behaviors of carbon fiber laminates under hygrothermal environment were studied using SHPB impact experiments. The results indicate that Carbon/Epoxy laminates have the strain rate sensitivity in the vertical direction, the maximum stress of the composite specimens increases nearly threefold as the strain rate increases from 1500s-1 to 6000s-1,, with an extremely slight change of the elastic modulus. Meanwhile, hygrothermal treatment can also improve the dynamic mechanical performance of this kind of material, the wet specimens exhibit higher dynamic compression strength perpendicular to the fiber ply, up to 12.45% compared to the dry specimens after 20 days hygrothermal treatment, and this phenomenon is more significant when the strain rate is relatively low.
Keywords: carbon fiber reinforced composites; hygrothermal environment; high strain rate; dynamic compression; SHPB
作者:吴以婷等,清华大学 航天航空学院,北京
通讯作者:葛东云,清华大学 航天航空学院,北京
全文详见中国知网学术期刊优先数字出版。