淡水鱼鳞片的结构及拉伸力学行为
Structure and tensile mechanical behavior of freshwater fish scales

硬骨鱼鳞片在长时间的自然进化过程中变得超薄、轻质，并具有良好的韧性。为了揭示其结构和力学性能，本文对产自新西兰的两种鱼鳞（鲤鱼、金鱼）进行了研究。首先对两种鳞片的形貌、横截面及其多级结构进行观察，然后对鳞片试样进行轴向拉伸测试。结果表明，鲤鱼和金鱼鳞片不同部位的表面形貌差异明显，而两种鳞片均由硬质骨质外层和软质胶原内层组成。鲤鱼鳞片应力在拟直线段后有小范围的下降，然后继续上升，直至达到峰值后降至零。对于金鱼鳞片，其应力在拟直线段后继续增加，达到峰值后逐渐降为零。比较两种鱼鳞的力学性能参数，金鱼鳞片的强度高于鲤鱼鳞片，但鲤鱼鱼鳞的延性优于金鱼鱼鳞。 During the long-term natural evolution, the scales of teleost fish become ultra-thin and lightweight and have a good flexibility as well. In order to reveal the structure and mechanism of scales, two scales of fish (cyprinus carpio, carassius auratus) from New Zealand were studied in this paper. Firstly, the surface morphology, cross-section and hierarchical structure of two fish scales were investigated. Then, uniaxial tensile tests were conducted. The results show that the surface morphologies of two scales are various from different location of scales, while two scales are both consist of outer hard bony layer and inner soft collagen layer. For cyprinus carpio scales, through a quasi-linear region from the stress-strain curves, the stress of samples softens slightly before reaching the first peak stress, after which the stress drops to zero. While the stress of carassius auratus scales increases through a quastic-linear region, and then reaches the peak, lastly drops to zero gradually. Comparing the mechanical parameters between cyprinus carpio scales and carassius auratus scales, it's suggested that the tensile strength of carassius auratus scales is superior to that of cyprinus carpio scales. However, the ductility of cyprinus carpio scales has a prior ductility than the carassius auratus scales. 装备预研教育部联合基金（青年人才）项目（6141A02033602）；国防科技创新特区项目（17-H863-03-ZT-003-008-06）；湖南省重点研发计划项目（2017GK2130）