【作者】 何伟；

【导师】 王钧；

【作者基本信息】 武汉理工大学 ， 复合材料学， 2008， 硕士

【摘要】 碳纤维增强树脂基复合材料(carbon fiber reinforced polymer,简称CFRP)具有高比强度、高比模、耐高温、耐腐蚀、耐疲劳、抗蠕变、导电、导热和热膨胀系数小等一系列优异性能,它们既可作为结构材料承载负荷,又可作为功能材料发挥作用,是一种功能结构材料。目前,它已广泛用于各个领域。但CFRP在制备过程中由于各种原因,如环境中的杂质、工艺实施不完善等因素造成最终复合材料制品中存在不同类型的缺陷。在复杂的使用环境中,多样的受力形式下这些缺陷往往成为应力集中点,发生诸如弱质纤维断裂、基体开裂、界面脱粘以及剪切破坏等多种损伤形式,首先诱发材料及其结构破坏的产生,引起复合材料性能下降。CFRP复合材料的非均质性使得其疲劳损伤常常是由多种损伤形式组合积累而致的,在其失去正常使用性能前无任何预兆,突然的断裂常常会导致无法估量的损失。因此,研究碳纤维树脂基复合材料的安全使用和在线健康监控有重大意义。本文首先研究了3201~#乙烯基树脂和柔性树脂增强三种不同编织形式的碳纤维复合材料在拉伸状态下的电阻率与应变之间的关系,作出电阻率-应变曲线。三种曲线的特点,均与碳纤维的编织形式密切有关。碳纤维毡复合材料在拉伸时的电阻率-应变曲线,能很好的拟合成一条直线,证实了电阻率与应变存在一一对应的关系,这一规律使得碳纤维毡树脂基复合材料可用于在线健康监控材料。通过对电极的研究,得出铜电极能够有效减少金属和非金属接触时的接触电阻,同时能保证输出的电信号稳定。试样的欧姆特性测试研究表明,碳纤维毡树脂基复合材料符合欧姆特性,证明拉伸实验时不会因为试样两端所加电压不同而不同,保证实验的可靠性。研究了拉伸实验时,电子万能试验机加载速率对碳纤维毡树脂基复合材料电阻率-应变曲线的影响。测试了一系列碳纤维毡复合材料在拉伸时的电阻率-应变曲线,分析碳纤维毡面密度和树脂种类对电阻率-应变曲线拟合参数和灵敏系数的影响,运用SPSS软件对参数进行回归,建立了相关的数学模型。更多还原

【Abstract】 Carbon fiber reinforced polymer composite materials(carbon fiber reinforced polymer,in sort of CFRP)possess a series of excellent characteristics,such as,high strength,high modulus,enduring high temperature,corrosion resistance,fatigue resistance,creep resistance,electrical conductivity,thermal conductivity and low thermal expansion coefficient.They can carry load as a structural material,but also play a role as a functional material,is a function of structural materials.Currently,it has been widely used in various fields.But for many reasons in the preparation process of CFRP,such as,impurities in the environment,the implementation of imperfect etc.there are different forms of defects in the final products.In the use of complex environment,under variety forms of stress,there may be stress focus on these defects cause many types of impair,such as weak fiber fracture,matrix cracking,the interfacial debonding and shear failure. First induced damage of material and the structure then caused the performance of composite materials decreased.The heterogeneity of CFRP composite materials make fatigue damage is often caused by various forms of portfolio accumulated damage, without any prior warning before its loss normal use,a sudden rupture often lead to incalculable damage.Therefore,there is great significance to study the safe use of CFRP and online health monitoring.In this paper,we initially make a series of CFRP which reinforced by three different forms of carbon fiber and two different kinds of polyester resin as matrix. Study on the relationship between resistivity and strain under tensile condition.The characteristics of three curves all closely related to the woven forms.The resistivitystrain curve under tensile condition of resin composites filler with short cut carbon felt can be fit a line,confirmed the one-to-one relationship between resistivity and strain.This law show that resin composites filler with short cut carbon felt can be used for online health Monitoring.And then examine the usages of electrodes on resin composites filler with short cut carbon felt,the result show that the copper electrodes can effectively reduce the contact resistance between metallic and non-metallic,and the output signal can guarantee stability.The Ohm testing proved that the electric conductivities of these kinds of materials are accordant to Ohm Theorem.This study showed that the resistivitystrain curve will not be changed for the different voltage in the tensile test.We studied the effect of resistivity-strain curve on the different loading rate of the machine in the tensile test.Test a series of resin composites filler with short cut carbon felt,analysis the effect of density and type of resin to the resistivity-strain curves and sensitivity coefficient.Using SPSS regression the parameters,established a mathematical model.更多还原