碳纤维/环氧树脂预浸带铺放应力场及制品微观结构的模拟与实验

Simulation and experiment study of stress field and microstructure of carbon fiber/epoxy resin prepreg laying products

  • 摘要: 碳纤维/环氧树脂预浸带复合材料在铺放成型时,由于树脂基体与碳纤维之间的热膨胀系数存在差异以及成型时热-力参数作用下由于纤维的变形而导致纤维与基体接触处产生应力集中等原因,在制品材料中会产生热残余应力。针对碳纤维/环氧树脂预浸带复合材料的实际结构特点,利用ABAQUS有限元软件建立含有界面的碳纤维/环氧树脂预浸带复合材料的细观代表性体积单元(Representative volume element, RVE)有限元模型,采用实验研究和有限元仿真分析的方法,研究在温度-压力参数作用下预浸带铺放制品残余应力的分布规律及影响机理。首先,建立预浸带铺放时的温度和压力模型,研究不同温度和压力参数条件下碳纤维/环氧树脂预浸带铺放制品残余应力的分布情况。其次,采用耦合降温法模拟碳纤维/环氧树脂预浸带残余应力随纤维体积含量、铺放压力以及铺放温度的变化规律,并采用扫描电镜对不同工艺参数条件下预浸带铺放制品的微观结构进行分析。通过对模拟结果进行分析比较得到各因素对制品残余应力的基本影响规律;最后进行不同温度和压力等铺放参数对预浸带铺放成型时残余应力影响的实验测试研究。

     

    Abstract: The deformation of fiber under the action of thermal mechanical parameters is caused by the differences of thermal expansion coefficient between the epoxy resin matrix and carbon fiber, and the stress concentration at the contact of fiber and matrix. Thermal residual stress is experienced in the product material during the laying process of carbon fiber/epoxy resin prepreg composites. Due to the structural characteristics of the carbon fiber/epoxy resin prepreg composite, the micro representative volume element (RVE) finite element model of the carbon fiber/epoxy resin prepreg composite with interface phase was established by using ABAQUS finite element software. The distribution rule and influence mechanism of the residual stress of the prepreg caused by temperature and pressure parameters were investigated by use of theoretical research and finite element simulation analysis. First, the temperature and pressure models of the prepreg were established to study the distribution of the residual stress of the products under different temperatures and pressure parameters. Second, the indirect coupling temperature reduction method was applied to simulate the change of residual stress of carbon fiber/epoxy resin prepreg with fiber volume content. Pressure, temperature and the microstructure of the product were analyzed by electron microscopy scanning. The basic influence rules of each factor on the residual stress of the products were thus obtained through analysis and comparison of the simulation results. In conclusion, the influences of different underlying parameters such as temperature and pressure on the residual stress of the prepreg were then tested.

     

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