混杂短纤维增强复合材料弹性模量预测

Prediction of the Elastic Modulus of Hybrid Short Fiber Reinforced Composites

在现代工程结构中,纤维增强复合材料具有较高的刚度重量比、优异的耐久性和设计灵活性等优点,因此得到了广泛应用.本文结合细观力学中的Mori-Tanaka方法和Halpin-Tsai方法推导了混杂碳纤维和玻璃纤维增强复合材料有效弹性模量的解析表达式.通过引入参数λ,提出了计算随机方向混合纤维增强复合材料弹性模量的新模型,分析了纤维长径比和体积分数对复合材料弹性模量的影响.结果表明,复合材料的弹性性能对纤维长径比和体积分数非常敏感.根据提出的理论,混杂纤维增强复合材料的弹性模量处于单一纤维(纯碳纤维或纯玻璃纤维)增强复合材料弹性模量之间.对于单一纤维增强复合材料,采用Halpin-Tsai方法计算的复合材料弹性模量高于Mori-Tanaka方法计算结果.

In modern engineering structures,fiber-reinforced composites are widely used due to their high stiffness-to-weight ratio,excellent durability,and high design flexibility.In the present study,an analytical expression for the effective elastic modulus of hybrid carbon fiber and glass fiber reinforced composites is derived by combining the Mori-Tanaka method and the Halpin-Tsai method of mesomechanics.By introducing the parameterλ,a new model for calculating the elastic modulus of randomly oriented hybrid fiber reinforced composites is proposed,and the effects of fiber aspect ratio and volume fraction on the elastic modulus of composites are analyzed.The analysis shows that the elastic properties of composites is very sensitive to the fiber aspect ratio and volume fraction.According to the proposed theory,the elastic modulus of the hybrid fiber reinforced composites is between those of the single fiber(pure carbon fiber or pure glass fiber)reinforced composites.For single fiber reinforced composites,the elastic modulus of the composites calculated by the Halpin-Tsai method is higher than that calculated by the Mori-Tanaka method.