碳纳米管导电复合材料垫片的制备与电阻蠕变性能研究

发布时间：2018-10-30 15:05

【摘要】：碳纳米管聚合物基复合材料是一种新型的导电聚合物基复合材料,具其优异的机械性能与电学性能。例如复合材料具有抗腐蚀、结构可设计性以及高强度等特点,可以将其设计成零件嵌入到设备或系统中,成为设备的一部分。另外一方面,复合材料具有良好的电阻响应敏感性,可根据电阻变化来监控、诊断设备的运行状态,实现传感器的功能。由此可见,复合材料在原位结构检测中具有巨大的潜力。但是由于基体材料的粘弹性,复合材料的电阻会发生蠕变行为,即在恒定应力的条件,电阻值会随着时间变化而变化,影响检测的稳定性,从而限制了应用的范围。因此,本文将用碳纳米管导电复合材料制备出导电垫片,并对导电垫片的电阻蠕变行为进行研究,总结其变化规律以及建立电阻蠕变模型。本文首先通过溶液混合浇铸法,制备出具有一定抗压性能与导电性能的碳纳米管导电复合材料垫片。同时,根据电阻蠕变实验的要求,从机械结构与测量系统两方面进行设计与开发,制备出电阻蠕变实验平台样机,然后利用该实验平台样机可进行不同应力条件下的碳纳米管复合材料的电阻蠕变实验。通过分析应变-时间曲线、电阻-时间曲线的特点以及应变与电阻之间的关系,总结出复合材料在蠕变过程中电阻的变化规律与机理。进一步,利用不同的应变蠕变理论模型,对电阻蠕变曲线进行拟合分析,获得复合材料在不同应力下的电阻蠕变模型。而获得模型之后,对电阻蠕变模型进行拟合误差分析,并修正模型参数,最后得到拟合效果较好的电阻蠕变模型与电阻-时间关系式,这对复合材料在原位结构检测中的应用,尤其在钢轨扣件应力的原位结构检测中的应用有一定的实际意义。
[Abstract]:Carbon nanotube polymer matrix composites are a new type of conductive polymer matrix composites with excellent mechanical and electrical properties. For example, composite materials have the characteristics of corrosion resistance, structural design and high strength. They can be embedded into the equipment or system and become part of the equipment. On the other hand, the composite material has good resistance response sensitivity, and can monitor and diagnose the operating state of the equipment according to the change of the resistance, and realize the function of the sensor. It can be seen that the composite has great potential in situ structure testing. However, because of the viscoelasticity of the matrix material, the resistance of the composite will creep behavior, that is, under the condition of constant stress, the resistance value will change with time, which will affect the stability of the detection, thus limiting the scope of application. Therefore, in this paper, conductive gaskets are prepared from carbon nanotube conductive composites, and the resistance creep behavior of conductive gaskets is studied, and the change law and resistance creep model of conductive gaskets are summarized. In this paper, carbon nanotube conductive composite gaskets with certain compressive and conductive properties were prepared by solution mixing casting method. At the same time, according to the requirements of resistance creep experiment, the prototype of resistance creep experiment platform is designed and developed from two aspects: mechanical structure and measuring system. Then the electrical creep experiments of carbon nanotube composites under different stress conditions can be carried out by using the experimental platform prototype. By analyzing the characteristics of strain-time curve, resistance-time curve and the relationship between strain and resistance, the variation law and mechanism of resistance in the creep process of composite materials are summarized. Furthermore, by using different strain creep theory models, the resistance creep curves are fitted and analyzed, and the resistance creep models of composites under different stresses are obtained. After obtaining the model, the fitting error of the resistance creep model is analyzed, and the model parameters are revised. Finally, the relationship between resistance creep model and resistance-time relationship is obtained, which is applied to the in-situ structure detection of composite materials. Especially in the rail fastener stress in situ structure detection has a certain practical significance.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332

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