Abstract Carbon Nanotubes (CNTs) are considered a promising reinforcement for engineering advanced structures, such as aerospace applications. It became inevitable to tailor structures not only by conventional geometric but also by mechanical properties tailoring, to acquire the maximum load-carrying capacity. Therefore, this research presented a novel Finite Element (FE) modeling of Axially Functionally Graded CNT Reinforced Composite (AFG-CNTRC) beams, based on Timoshenko beam theory. However, an obstacle is raised due to properties discontinuity produced between consecutive elements in axial gradation. A solution is proposed based on the ladder-pattern concept. It defined a locally specific value at each element, satisfying the overall required distribution. It followed by a convergence test, static, and dynamic analysis with comprehensive parametric studies. The obtained results showed that the model is convergent, accurate, free of shear-locking, and suitable for axial gradation. Moreover, this study introduced an advanced technique for axial properties tailoring, utilizing privileges of CNT and aggregation. The longitudinal tailoring depends on both the CNT orientation angle and gradation index, which played a crucial role in response control and adjusting beam stiffness together with strength. This approach could solve enormous engineering problems, especially at critical cross-sections design and constraint response, without affecting the total weight.

中文翻译：

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功能梯度碳纳米管增强复合梁的纵向建模和性能裁剪：一种新方法

摘要 碳纳米管 (CNT) 被认为是工程先进结构的有前途的增强材料，例如航空航天应用。为了获得最大的承载能力，不仅通过传统的几何形状而且通过力学性能的裁剪来裁剪结构变得不可避免。因此，本研究基于 Timoshenko 梁理论，提出了一种新型的轴向功能梯度 CNT 增强复合材料 (AFG-CNTRC) 梁的有限元 (FE) 建模。然而，由于轴向渐变中连续元素之间产生的属性不连续性，会增加一个障碍。提出了一种基于阶梯模式概念的解决方案。它在每个元素上定义了一个局部特定值，满足整体所需的分布。然后是收敛测试，静态，和动态分析与全面的参数研究。计算结果表明，该模型收敛性好、精度高、无剪切锁死、适用于轴向级配。此外，这项研究引入了一种先进的轴向特性裁剪技术，利用了 CNT 和聚合的特权。纵向剪裁取决于碳纳米管取向角和梯度指数，这在响应控制和调整梁刚度和强度方面起着至关重要的作用。这种方法可以解决巨大的工程问题，尤其是在关键横截面设计和约束响应方面，而不会影响总重量。这项研究引入了一种先进的轴向特性裁剪技术，利用了 CNT 和聚合的特权。纵向剪裁取决于碳纳米管取向角和梯度指数，这在响应控制和调整梁刚度和强度方面起着至关重要的作用。这种方法可以解决巨大的工程问题，尤其是在关键横截面设计和约束响应方面，而不会影响总重量。这项研究引入了一种先进的轴向特性裁剪技术，利用了 CNT 和聚合的特权。纵向剪裁取决于碳纳米管取向角和梯度指数，这在响应控制和调整梁刚度和强度方面起着至关重要的作用。这种方法可以解决巨大的工程问题，尤其是在关键横截面设计和约束响应方面，而不会影响总重量。