A Spider Silk Like Fiber for Vibration Damping

本课题的目标是设计、合成、表征和建模一种类似蜘蛛丝的振动控制纤维。高阻尼合成纤维将模仿蛛丝的微观结构。在本项目中，现有熔融自旋聚氨酯纤维的组成将通过定制硬相域和软相域、分子链刚性、分子量和分布、氢键和交联密度来进行改性。在熔融纺丝过程中，通过冷拉伸和减小纤维直径使合成纤维增强硬化。一旦纤维制成，将对其化学、物理和机械性能进行表征，并给出反馈，以进一步改进其组成和聚合，以及冷张力，直到它与拖丝蜘蛛丝竞争。然后对其减振能力进行评估。在动态载荷作用下，基于物理的合成纤维多尺度建模将得到发展。该模型将纤维的微观结构与其在很宽的温度和频率范围内的阻尼特性联系起来。研究结果将为进一步改进光纤设计提供指导。如果成功，该项目将创造基础知识，并提供对一种新型合成纤维模仿拖丝的基本理解。它最终可能使制造大量具有与蜘蛛丝相当的机械和阻尼性能的合成纤维成为可能。预计该项目将为聚合物纤维在轻量化承重结构中的应用开辟新的机遇。所获得的知识也可以扩展到其他材料，如用于桥梁和建筑物减振的纤维增强水泥混凝土。该项目将支持本科生和研究生（包括南方大学的少数民族学生）以及高中生通过动手实验室工作和科学与工程博览会项目进行高级培训。

The objective of this project is to design, synthesize, characterize, and model a spider silk like fiber for vibration control. The high damping synthetic fiber will mimic the microstructure of spider silk. In this project, the composition of existing melt-spin polyurethane fiber will be modified by tailoring the hard phase domain and soft phase domain, molecular chain rigidity, molecular weight and distribution, hydrogen bond, and cross-link density. The synthetic fiber will be strengthened and hardened by cold-stretching and by reducing fiber diameter during the melt-spinning process. Once the fiber is fabricated, its chemical, physical, and mechanical properties will be characterized and feed-back will be given to further refine its composition and polymerization, as well as cold-tension, until it is competitive with dragline spider silk. Its vibration damping capability will then be evaluated. Physics based multi-scale modeling of the synthetic fiber under dynamic loading will be developed. The model will link the microstructure of the fiber with its damping properties over a wide range of temperature and frequency. The result will provide guidance for further improvement in fiber design. If successful, this project will create fundamental knowledge and provide basic understanding of a novel synthetic fiber mimicking dragline spider silk. It may eventually make it possible to manufacture a large amount of synthetic fibers that have mechanical and damping properties comparable to those of spider silks. It is expected that this project will open up new opportunities for application of polymeric fibers in lightweight load-bearing structures. The derived knowledge can also be extended to other materials such as fiber reinforced cement concrete for vibration damping in bridges and buildings. This project will support advanced training for undergraduate and graduate students, including minority students at Southern University, and high school students through hands on laboratory work and Science and Engineering Fair projects.