Wang Xiong, Lin Changliang, Li Liang, Lu Yang, Zhu Xizhe, Wang Wenjie
Aircraft Design and Research Institute, Harbin Aircraft Industry (Group) Co., Ltd., Harbin 150066, China.
Tianjin Civil Helicopter R&D Branch, Harbin Aircraft Industry (Group) Co., Ltd., Tianjin 300450, China.
Materials (Basel). 2025 Jul 18;18(14):3371. doi: 10.3390/ma18143371.
Addressing the urgent need for lightweight and reusable energy-absorbing materials in aviation impact resistance, this study introduces an innovative multi-directional braided metamaterial design enabled by 4D printing technology. This approach overcomes the dual challenges of intricate manufacturing processes and the limited functionality inherent to traditional textile preforms. Six distinct braided structural units (types 1-6) were devised based on periodic trigonometric functions (Y = A sin(12πX)), and integrated with shape memory polylactic acid (SMP-PLA), thereby achieving a synergistic combination of topological architecture and adaptive response characteristics. Compression tests reveal that reducing strip density to 50-25% (as in types 1-3) markedly enhances energy absorption performance, achieving a maximum specific energy absorption of 3.3 J/g. Three-point bending tests further demonstrate that the yarn amplitude parameter A is inversely correlated with load-bearing capacity; for instance, the type 1 structure (A = 3) withstands a maximum load stress of 8 MPa, representing a 100% increase compared to the type 2 structure (A = 4.5). A multi-branch viscoelastic constitutive model elucidates the temperature-dependent stress relaxation behavior during the glass-rubber phase transition and clarifies the relaxation time conversion mechanism governed by the Williams-Landel-Ferry (WLF) and Arrhenius equations. Experimental results further confirm the shape memory effect, with the type 3 structure fully recovering its original shape within 3 s under thermal stimulation at 80 °C, thus addressing the non-reusability issue of conventional energy-absorbing structures. This work establishes a new paradigm for the design of impact-resistant aviation components, particularly in the context of anti-collision structures and reusable energy absorption systems for eVTOL aircraft. Future research should further investigate the regulation of multi-stimulus response behaviors and microstructural optimization to advance the engineering application of smart textile metamaterials in aviation protection systems.
为满足航空抗冲击领域对轻质且可重复使用的能量吸收材料的迫切需求，本研究引入了一种由4D打印技术实现的创新型多向编织超材料设计。这种方法克服了复杂制造工艺以及传统纺织预制件固有功能有限的双重挑战。基于周期性三角函数（Y = A sin(12πX)）设计了六种不同的编织结构单元（类型1 - 6），并与形状记忆聚乳酸（SMP - PLA）集成，从而实现了拓扑结构与自适应响应特性的协同组合。压缩测试表明，将条带密度降低至50 - 25%（如类型1 - 3）可显著提高能量吸收性能，实现最大比能量吸收为3.3 J/g。三点弯曲测试进一步表明，纱线振幅参数A与承载能力呈负相关；例如，类型1结构（A = 3）承受的最大负载应力为8 MPa，相比类型2结构（A = 4.5）增加了100%。一个多分支粘弹性本构模型阐明了玻璃 - 橡胶相变过程中与温度相关的应力松弛行为，并明确了由威廉姆斯 - 兰德尔 - 费里（WLF）和阿伦尼乌斯方程控制的松弛时间转换机制。实验结果进一步证实了形状记忆效应，类型3结构在80°C热刺激下3秒内完全恢复其原始形状，从而解决了传统能量吸收结构不可重复使用的问题。这项工作为抗冲击航空部件的设计建立了新范式，特别是在eVTOL飞机的防撞结构和可重复使用能量吸收系统方面。未来的研究应进一步探究多刺激响应行为的调控和微观结构优化，以推动智能纺织超材料在航空保护系统中的工程应用。
