碳纳米线的拉伸应变传感特性

为开发用于三维编织复合材料原位结构健康监测的碳纳米线传感器，建立了碳纳米线应变传感实验系统，通过纵向拉伸实验，分析了碳纳米线的机械性能（应力和应变）和电性能（初始电阻和应变灵敏系数）之间的关系，并对性能参数进行了Weibull 统计分析，系统研究了碳纳米线的应变传感特性。结果表明：纵向拉伸负载期间，碳纳米线相对电阻变化与应变呈现良好的线性关系；碳纳米线具有与传统应变监测相当的应变灵敏系数，适合用于检测破坏极限应变远小于碳纳米线应变（碳纳米线的破坏应变均值10％，最小值为2.5％）的复合材料的损伤，是复合材料结构健康监测传感器的良好候选材料。

Tensile strain sensing characteristics of carbon nanoyarns

In order to develop carbon nanoyarn sensors used in three-dimensional braided composites in-situ structural health monitoring,a carbon nanoyarn strain sensing experiment system was established.By the longitudinal tensile experiment, the correlation between the mechanical properties (stress and strain) and the electrical properties (initial resistance and strain sensitivity coefficient) of carbon nanoyarns was investigated, andWeibull statistical analysis onperformance parameters was conducted.The strain sensing characteristics of carbon nanoyarns weresystematically studied.The results show that the relative resistance variation and the strain of carbon nanoyarns under longitudinal tensile load have a good linear correlation. Besides, carbon nanoyarns provide a strain sensitivity coefficient equivalent to conventional strain monitoring, which is very suitable for monitoring composites whose failure strain limit is far less than the strain of carbon nanoyarns(carbon nanoyarns damage strain mean of10% andthe minimum value of 2.5%). Therefore, carbon nanoyarns become a good candidate material of sensors for composite structural health monitoring.