基于形状记忆聚合物仿生复合材料的力学性能

发布时间：2018-05-28 12:02

本文选题：波纹纤维 + 形状记忆　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：形状记忆聚合物是一种特殊的高分子聚合物。该种材料具有刚度随温度而改变的特点(低温时高刚度,高温时低刚度)。鲨鱼皮肋条结构是鲨鱼皮表面的一种沟槽结构,该结构能够减少物体在流体中流动时产生的阻力,其机理在于流体在沟槽中流动时会形成二次涡,二次涡能够削弱湍流的产生从而达到减少阻力的目的。本文制备了一种波纹形弹性纤维增强的形状记忆聚合物复合材料,该复合材料具有通过加热改变自身刚度的特性,由于材料变刚度的特点以及纤维波纹形状的几何特性,使得该材料在高温单轴拉伸的情况下,基体表面上可产生沟槽结构,降低温度时,复合材料刚度变大,沟槽结构锁定变形,故可将此种材料作为制备仿鲨鱼皮肋条结构的材料。本文的主要研究内容包括波纹形纤维增强复合材料制备方法的研究以及力学性能研究。建立了预测波纹纤维面外位移的一种理论,建立了大变形情况下,复合材料的应力-应变关系,计算了大变形情况下的柔度矩阵。为了更好的研究形状记忆聚合物复合材料的基本力学性能,本文进行了一系列的力学性能表征,包括形状记忆聚合物基体的热-机械性能测试(DMA)、复合材料的常温及高温下拉伸实验,分析了材料在拉伸状态下的力学性能,利用三维光学散斑系统测量复合材料的应变和位移,观察到材料在高温拉伸下表面沟槽结构的形成,得到了沟槽结构随时间的变化图。最后,本文仿真了材料在单轴拉伸载荷下的变形情况。得出了材料的变形图,位移云图,仿真结果显示在材料的表面确实形成了沟槽结构。根据仿真的结果,输出了纤维的面外位移,并与本文得到的预测纤维面外变形的理论做对比,发现理论值与仿真值误差最大为13.253%。
[Abstract]:Shape memory polymer is a special kind of polymer. The material has the characteristics of the stiffness varying with the temperature (high stiffness at low temperature, low stiffness at high temperature). The shark skin rib structure is a groove structure on the surface of the shark skin, which can reduce the resistance of the body in the fluid flow. The mechanism lies in the fluid in the structure. Two vortices are formed in the flow of the grooves. The two vortices can weaken the formation of the turbulence and thus reduce the resistance. A corrugated elastic fiber reinforced shape memory polymer composite has been prepared. The composite has the characteristics of changing its stiffness by heating and the characteristics of material stiffness and fiber wave. The geometric characteristics of the grain shape make the material produce grooves on the surface of the matrix under the condition of high temperature uniaxial tension. When the temperature is reduced, the stiffness of the composite material becomes larger and the groove structure is locked. Therefore, this material can be used as a material to prepare the shark skin rib structure. The main contents of this paper include corrugated fiber reinforcement. Research on the preparation of composite materials and the study of mechanical properties. A theory for predicting the displacement of corrugated fibers is established. The stress strain relationship of composite materials under large deformation is established and the flexibility matrix of large deformation is calculated. In order to better study the basic mechanical properties of the shape memristor polymer composites, the basic mechanical properties of the composite materials are studied better. A series of mechanical properties were characterized, including the thermal mechanical properties test (DMA) of the shape memory polymer matrix, the tensile test at normal temperature and high temperature of the composite. The mechanical properties of the material under tensile state were analyzed. The strain and displacement of the composite were measured by the three-dimensional optical speckle system, and the tensile strength was observed at high temperature. In the end, the deformation of the material under uniaxial tension is simulated. The deformation diagram of the material and the displacement cloud are obtained. The simulation results show that the groove structure does form on the surface of the material. The out of plane displacement of the fiber is output according to the simulation results. Compared with the theory of prediction of fiber out of plane deformation, the maximum error of theoretical value and simulation value is 13.253%.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TQ317

【参考文献】