【摘要】 采用非接触式单丝模量测试系统对单丝炭纤维拉伸过程中的模量变化进行测量和分析。对比研究了聚丙烯腈基和沥青基炭纤维5种样品的模量和非线性行为。实验结果表明,5种单丝炭纤维均呈现出拉伸变形的非线性行为,但其非线性力学行为特征有所不同。研究发现,随着炭纤维模量的增大,非线性系数明显增加。聚丙烯腈基炭纤维T300和T700样品的模量接近,计算得到的非线性系数较一致,分别为19.3和19.7,而模量较高的M40J的非线性系数增加至22.3。自制沥青基炭纤维则表现出更强的非线性行为,分别为41.8和63.5,且随着模量增加,非线性系数增加的程度高于聚丙烯腈基炭纤维样品。更多还原

【Abstract】 A non-contact laser micrometer was introduced to a conventional single filament tensile testing instrument to directly measure the small displacement of single carbon fiber samples, allowing the modified system to measure and monitor the change of Young’s modulus during the fiber stretching process simultaneously and accurately. The non-linear behaviors of single carbon fibers from both polyacrylonitrile and mesophase pitch feedstock were studied and compared in terms of the coefficient describing the modulus dependency on strain. It was found that all five types of carbon fibers exhibit similar non-Hookean elastic behaviors, which increases with the initial modulus. The non-linear coefficients of polyacrylonitrile based carbon fibers are similar with those of T300 and T700, which are 19.3 and 19.7, respectively. While for M40 J with higher Young’s modulus, the non-linear coefficient is around22.3. The self-manufactured mesophase pitch based carbon fibers with similar initial modulus to that of polyacrylonitrile based carbon fiber, had much higher non-linear coefficients(41.8 and 63.5), which presents stronger non-linearity in mechanical properties.The increment of nonlinear coefficient with the initial modulus for mesophase pitch-based carbon fibers was much higher than that of polyacrylonitrile-based carbon fibers as well.更多还原