Carbon nanotube (CNT) yarns have demonstrated promising mechanical properties and scalability for composite applications. In this study, a commercially available continuous CNT yarn and two modified versions at large gauge lengths (~110 mm) were tested to reveal engineering properties. The as-received yarns with a large cross-section demonstrated the highest specific tensile strength (0.911 ± 0.137 N/tex), while the highly densified yarns showed the lowest specific tensile strength (0.337 ± 0.217 N/tex). Results suggest that alignment governs the ultimate tensile strength, while defects dictate how yarns fail and the harnessed strength potential. Of the two failure modes detected, brittle edge failures experienced greater ultimate tensile strengths ranging from ~8 to 20% depending on the yarn type. The test results were fitted to 2-parameter Weibull distributions to further confirm the failure behavior. These results indicate valuable properties for industrial CNT yarn applications and provide a baseline for large gauge length CNT studies.

碳纳米管（CNT）纱线已证明具有广阔的机械性能和可扩展性，可用于复合材料。在这项研究中，测试了市售的连续CNT纱线和两个大规格长度（〜110 mm）的改性版本，以揭示其工程性能。收到的横截面大的纱线显示出最高的比抗张强度（0.911±0.137 N / tex），而高密度的纱线显示出最低的比抗张强度（0.337±0.217 N / tex）。结果表明，对齐方式决定了最终的拉伸强度，而缺陷则决定了纱线如何断裂以及线束强度的潜力。在检测到的两种破坏模式中，脆性边缘破坏会承受更大的极限拉伸强度，具体取决于纱线类型，其极限拉伸强度范围约为〜20％。将测试结果拟合为2参数Weibull分布，以进一步确认失效行为。这些结果表明了工业CNT纱线应用的宝贵性能，并为大规格CNT研究提供了基线。