In this paper, theoretical and experimental studies are carried out to investigate the damping characteristics of carbon nanotube (CNT) reinforced epoxy nanocomposite beams. A modified Biot model is proposed to simulate the frequency-dependent damping characteristics of CNT reinforced epoxy nanocomposites and implemented into the finite element model for composite beams. The natural frequencies and modal damping ratios of CNT reinforced epoxy beams are predicted using the proposed finite element model. Then, CNT reinforced epoxy beam specimens are fabricated, upon which dynamic mechanical analysis and vibration tests are carried out. Comparison studies between theoretical and experimental results show that modified Biot model proposed here is more accurate than the original one in predicting loss factors of CNT reinforced epoxy nanocomposites. It is revealed that the damping ratios associated with the first three vibration modes of composite beam specimens initially increase and then decrease with the increment of CNT weight ratio. The first order damping ratio with 0.4 wt% CNT reinforcement has the maximum value of 0.591%, which is improved by 41% compared with that of pure epoxy.

在本文中，进行了理论和实验研究，以研究碳纳米管（CNT）增强环氧树脂纳米复合梁的阻尼特性。提出了一种改进的 Biot 模型来模拟 CNT 增强环氧树脂纳米复合材料的频率相关阻尼特性，并将其实施到复合梁的有限元模型中。使用所提出的有限元模型预测了碳纳米管增强环氧树脂梁的固有频率和模态阻尼比。然后，制作碳纳米管增强环氧树脂梁试样，对其进行动态力学分析和振动试验。理论和实验结果的比较研究表明，本文提出的修正 Biot 模型在预测 CNT 增强环氧树脂纳米复合材料的损耗因子方面比原始模型更准确。结果表明，随着碳纳米管重量比的增加，与复合梁试件前三种振动模式相关的阻尼比先增加后减小。0.4 wt% CNT增强的一阶阻尼比最大值为0.591%，与纯环氧树脂相比提高了41%。