The study of the mechanical characteristics and microwave absorption capabilities of multifunctional composite materials in complex environments has attracted considerable interest in recent years. Inspired by the structure of bamboo in nature, a novel double-layer microwave absorber structure, a CB/PLA-TPU composite bionic bamboo joint’s structure, was conceived and manufactured for this investigation. This structure ingeniously integrates the load-bearing attributes of bamboo joints with the microwave absorption qualities of CB composites. At the material level, enhancing the CB particle content enhances the matrix's folds and defects, thereby improving its dielectric polarization loss capacity. An effective absorption bandwidth of 3.84 GHz was achieved, with a minimum reflection loss of −60.24 dB at a 2.58 mm thickness and a 9.2 GHz frequency. The bionic bamboo absorber's unit structure is meticulously engineered, with experimental simulations validating its performance. According to the findings, the structure attains a 10.03 GHz broadband absorption and a yield strength of 11.6 MPa. It maintains broadband absorption capabilities above 9 GHz even at oblique incidence angles for TM polar wave (0–60°) and TE polar wave (0–30°). The biomimetic design based on bamboo offers significant potential for engineering applications in stealth technology under adverse conditions.

中文翻译：

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基于CB/PLA-TPU复合材料的双层仿生竹结构吸波体的制备及其宽带微波吸收特性

近年来，复杂环境下多功能复合材料的力学特性和微波吸收能力的研究引起了人们的广泛兴趣。受自然界竹子结构的启发，本次研究构思并制造了一种新型双层微波吸收体结构，即CB/PLA-TPU复合仿生竹节结构。这种结构巧妙地将竹节的承重特性与炭黑复合材料的微波吸收特性结合在一起。在材料层面，提高CB颗粒含量可以增强基体的褶皱和缺陷，从而提高其介电极化损耗能力。实现了 3.84 GHz 的有效吸收带宽，在 2.58 mm 厚度和 9.2 GHz 频率下的最小反射损耗为 -60.24 dB。仿生竹吸波器的单元结构经过精心设计，并通过实验模拟验证了其性能。根据研究结果，该结构实现了 10.03 GHz 宽带吸收和 11.6 MPa 的屈服强度。即使在 TM 极波 (0–60°) 和 TE 极波 (0–30°) 的斜入射角下，它也能保持 9 GHz 以上的宽带吸收能力。基于竹子的仿生设计为恶劣条件下的隐身技术的工程应用提供了巨大的潜力。