Scientists have reported that plant leaf veins grow into an optimized architecture not only to accomplish their biological and physiological functions but also to sustain the environmental loads. Researchers showed that the wind blade mimicking the leaf architecture could always have relatively lower internal strain energy, better static strength and stiffness, smaller stress intensity, and higher fatigue life compared with the conventional blade structures. However, the plant leaf-mimetic wind blade has so far remained at the level of simulations. Here, a new paradigm for design and fabrication of wind blades is demonstrated by 4D printing process, which combines several beneficial attributes in one blade. The proposed blade having the plant leaf structure can show reversible bend-twist coupling (BTC). It does not rely on conventional electromechanical systems such as sensors and actuators to determine proper deflection and change its shape. Additionally, the existing blades capable of BTC through passive methods have inherent flutter instability since they need to be flexible. The proposed blade may solve the flutter challenge. Lastly, this multi-functional blade can lead to eco-friendly wind turbines. Wind-tunnel tests, CFD, and performance analysis are performed on the proposed blade to demonstrate its applicability.

中文翻译：

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通过 4D 打印模拟植物叶片的智能风力涡轮机叶片

科学家们报告说，植物叶脉生长成优化的结构，不仅可以完成其生物和生理功能，还可以承受环境负荷。研究人员表明，与传统叶片结构相比，模仿叶片结构的风力叶片始终具有相对较低的内部应变能、更好的静态强度和刚度、更小的应力强度和更高的疲劳寿命。然而，植物叶片模拟风叶迄今仍停留在模拟水平。在这里，4D 打印工艺展示了风力叶片设计和制造的新范式，该工艺在一个叶片中结合了多种有益特性。具有植物叶片结构的拟议叶片可以显示可逆弯曲 - 扭曲耦合（BTC）。它不依赖于传感器和执行器等传统机电系统来确定适当的偏转并改变其形状。此外，能够通过被动方法进行 BTC 的现有叶片具有固有的颤振不稳定性，因为它们需要具有灵活性。提议的叶片可以解决颤振挑战。最后，这种多功能叶片可以打造环保型风力涡轮机。对提议的叶片进行风洞测试、CFD 和性能分析，以证明其适用性。这种多功能叶片可以打造环保型风力涡轮机。对提议的叶片进行风洞测试、CFD 和性能分析，以证明其适用性。这种多功能叶片可以打造环保型风力涡轮机。对提议的叶片进行风洞测试、CFD 和性能分析，以证明其适用性。