纤维增强树脂复合材料中的褶皱缺陷:分散性与虚拟测试

Wrinkles in fiber-reinforced resin composites: Heterogeneity and virtual test

  • 摘要: 在纤维增强树脂复合材料结构中,褶皱缺陷的物理形态及其空间分布通常具有分散性,如果仅追踪某个单一褶皱缺陷的行为演化,则不能有效控制复合材料批量构件性能的一致性。本论文提出了一种褶皱缺陷分散性模型,该模型包括褶皱形态的正态分布和空间位置的随机分布,以及将该模型植入自主开发的有限元程序的算法实现。由于计算程序中考虑了褶皱缺陷的概率分布,每进行一次力学响应计算就相当于进行一次复合材料结构虚拟测试,计算程序运行多次即可获得结构响应的上、下限,在设计阶段就可以预测褶皱缺陷分散性对结构宏观力学响应的影响,并在缺陷的统计指标和构件的力学性能之间建立量化关系。所建立的虚拟测试方法是复合材料创新设计方法的关键,能有效减少工程实践中复合材料结构对大批量试验的依赖。

     

    Abstract: The physical morphology of wrinkles and their spatial distribution in fiber-reinforced resin composites show inhomogeneity. It’s no use to improve the performance consistency of composite structures if just tracking the evolution and effect of a specific wrinkle. This paper proposed a novel model which considered the normal distribution of wrinkle’s geometrical size and the spatial random distribution, and the implementation algorithm of the model implanted in a self-developed finite element procedure is achieved. The computation combining hetero-geneous wrinkles can be considered as a virtual test since it allows every computation to produce a different result, thus the upper and lower limits of structural response can be obtained by multiple computations. The influence of wrinkle heterogeneity on macro-mechanical response can be predicted in design stage, and a quantitative relationship between the statistical parameters of defects and mechanical properties can be established. The virtual test method is the key to the innovative design method of composites, which can effectively reduce the dependence of mass testing of composite material in engineering practice.

     

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