碳/环氧树脂复合材料应变率效应的实验研究

选择两种铺设方式( _S和 _S)的T300/Epoxy(炭纤维/环氧树脂)层合板, 利用MTS试验机以及Hopkinson拉伸杆分别对其进行了准静态拉伸试验(应变率为10-5~10-4 s-1)、 中应变率拉伸试验(应变率为100 ~101s-1)和高速冲击拉伸试验(应变率为102~104s-1)。静态、 动态实验的试件形状及尺寸均相同。获得了不同应变率加载条件下T300/Epoxy的应力-应变曲线。基于所获得的应力-应变曲线, 讨论了应变率对炭纤维增强复合材料力学性能的影响。研究结果表明: 复合材料T300/Epoxy是应变率相关的材料; 层合板的铺设方向对其应变率效应有着显著的影响; 随着应变率的增加, 材料的强度及弹性模量有较大程度的提高, 但破坏应变有所降低。通过对试验结果的数据拟合, 提出了材料应变率相关的动态本构模型。 

Experiment study on the strain rate behavior of carbon/epoxy composite materials

The strain rate dependent behavior of T300 carbon/epoxy matrix composite in tension was studied by testing two kinds of laminates S and S at different rates. The tensile test was carried out on an MTS machine at the quasi-static strain rates of approximately 10-5~10-4 s-1 and the intermediate strain rates of about 100~101s-1. The tensile high strain rate test was conducted with the tensile split Hopkinson bar technique at strain rates of approximately 102~104 s-1. The specimens with identical geometry were used in all the tests. The dynamic stress-strain plot was obtained and compared with the quasi-static tensile test result. The results of the study indicate that Carbon/Epoxy composites are strain rate dependent materials. The stacking sequence has a significant effect on the material response. The tensile strength of the composites increases with increasing the strain rate, and the failure strain decreases when the strain rate increases. A constitutive model for characterizing the strain rate dependent behavior of T300/Epoxy composites was derived by simulating the experimental data.