随机植物短纤维复合材料界面性能对有效模量和拉伸行为的影响

发布时间：2018-05-04 06:49

本文选题：短植物纤维 + 拉伸性能　；参考：《材料研究学报》2016年09期

【摘要】：研究了界面性能对随机短云杉纤维增强聚丙烯(PP)复合材料宏观拉伸性能的影响。采用双线性内聚力模型(CZM)描述随机短云杉纤维和PP基体间非理想界面的力学行为,建立了含非理想界面的随机短纤维增强复合材料代表性单元(RVE)的二维有限元模型,考虑了纤维含量、长细比、随机分布和随机各向异性弹性以及PP基体弹塑性的影响;模拟了不同纤维含量复合材料的实验拉伸应力应变曲线。结果表明,短云杉纤维/PP基体间非理想界面刚度与复合材料有效弹性模量之间有单调递增的曲线关系,即E-K曲线;同一复合材料不同纤维含量的E-K曲线簇有一个临界交点。在交点右侧强界面刚度区复合材料有效模量随着纤维含量的增加而提高,在交点左侧弱界面刚度区有效模量随着纤维含量的增加而减少。三种不同体积含量10%、20%和49%的云杉/PP复合材料的非理想界面刚度可用E-K曲线和实验测得的宏观有效弹性模量确定,云杉/PP界面初始破坏位移和界面完全破坏位移也可根据模拟拉伸应力应变曲线确定。数值分析结果能用非理想界面刚度来解释和理解随机短植物纤维体积含量对复合材料宏观有效模量的影响。
[Abstract]:The effect of interfacial properties on the macroscopic tensile properties of random spruce fiber reinforced polypropylene (PP) composites was studied. A bilinear cohesive force model (CZM) was used to describe the mechanical behavior of the nonideal interface between the random spruce fiber and the PP matrix. A two-dimensional finite element model was established for the representative element of the random short fiber reinforced composites (RVEs) with non-ideal interfaces. The effects of fiber content, slenderness ratio, random distribution, random anisotropic elasticity and elastoplasticity of PP matrix were considered, and the tensile stress-strain curves of composites with different fiber contents were simulated. The results show that the non-ideal interfacial stiffness between spruce fiber / PP matrix and the effective elastic modulus of the composites increase monotonously, i.e. E-K curve, and the E-K curve cluster with different fiber content has a critical intersection point. The effective modulus of composites increases with the increase of fiber content at the right side of the intersection point, and decreases with the increase of fiber content in the weak interface zone on the left side of the intersection point. The nonideal interfacial stiffness of three kinds of spruce / PP composites with 10% and 49% different volume contents can be determined by E-K curve and macroscopic effective elastic modulus measured experimentally. The initial failure displacement and the complete failure displacement of spruce / PP interface can also be determined according to the simulated tensile stress-strain curve. The results of numerical analysis can be used to explain and understand the effect of the volume content of random short plant fiber on the macroscopic effective modulus of composites by using the non-ideal interface stiffness.
【作者单位】：天津大学机械工程学院;
【基金】：国家自然科学基金10972155,11572218和81670884资助项目~~
【分类号】：TB332

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