The presence of voids in woven fabric composite (WFC) significantly affects the mechanical and thermomechanical properties. Void defects are introduced during the resin infiltration process due to various controlling parameters involved in the curing process, i.e., pressure, temperature, resin flow etc. In this study, the mechanical constants of 2D woven fabric composite were experimentally determined. A finite element (FE) based representative volume element (RVE) model has been validated against these experimental results. A multiscale-based FE model has been developed, and periodic boundary conditions are applied to the RVE model to evaluate the homogenized thermomechanical properties of WFC containing void defects. Present numerical model incorporates the geometrical microstructures of the post-cured woven composite and void contents obtained from X-ray microtomography. The influence of void defect and resin infiltration have been incorporated to evaluate the thermomechanical properties of plain WFC. A parametric study has been carried out with respect to the variation of void defects on thermoelastic properties of E-glass/epoxy plain WFC. The variation of void defects has been considered in micro and mesoscale models. Monte Carlo simulations further quantified the effects of void content on the thermomechanical constants of WFC. The presence of voids has been observed to have significant influences on the thermomechanical constants of yarn and woven fabric composites.

中文翻译：

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含空隙缺陷的无碱玻璃/环氧树脂平纹织物复合材料的实验和数值表征


机织织物复合材料 （WFC） 中空隙的存在会显着影响机械和热机械性能。由于固化过程中涉及各种控制参数，即压力、温度、树脂流动等，在树脂渗透过程中会引入空隙缺陷。在本研究中，实验确定了 2D 机织织物复合材料的力学常数。基于有限元 （FE） 的代表性体积元 （RVE） 模型已针对这些实验结果进行了验证。已经开发了一种基于多尺度的有限元模型，并将周期性边界条件应用于 RVE 模型，以评估包含空隙缺陷的 WFC 的均匀热机械性能。本数值模型结合了后固化编织复合材料的几何微观结构和从 X 射线显微断层扫描获得的空隙内容物。空隙缺陷和树脂渗透的影响已被纳入评估普通 WFC 的热机械性能。已经对空隙缺陷对 E 玻璃/环氧树脂普通 WFC 的热弹性性能的变化进行了参数研究。在微观和中尺度模型中已经考虑了空隙缺陷的变化。蒙特卡洛模拟进一步量化了空隙含量对 WFC 热机械常数的影响。据观察，空隙的存在对纱线和机织织物复合材料的热机械常数有重大影响。