Shen Rulin, Liu Taizhi, Liu Hehua, Zou Xiangfu, Gong Yanling, Guo Haibo
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
Polymers (Basel). 2024 May 13;16(10):1386. doi: 10.3390/polym16101386.
In this paper, an enhanced VARTM process is proposed and its pressure effect on resin infusion behavior and composite material performance is studied to reveal the control mechanism of the fiber volume fraction and void content. The molding is vacuumized during the resin injection stage while it is pressurized during the mold filling and curing stages via a VARTM pressure control system designed in this paper. Theoretical calculations and simulation methods are used to reveal the resin's in-plane, transverse, and three-dimensional flow patterns in multi-layer media. For typical thin-walled components, the infiltration behavior of resin in isotropic porous media is studied, elucidating the control mechanisms of fiber volume fraction and void content. The experiments demonstrate that the enhanced VARTM process significantly improves mold filling efficiency and composite's performance. Compared to the regular VARTM process, the panel thickness is reduced by 4% from 1.7 mm, the average tensile strength is increased by 7.3% to 760 MPa, the average flexural strength remains at approximately 720 MPa, porosity is decreased from 1.5% to below 1%, and the fiber volume fraction is increased from 55% to 62%.
本文提出了一种改进的真空辅助树脂传递模塑（VARTM）工艺，研究了其压力对树脂灌注行为和复合材料性能的影响，以揭示纤维体积分数和孔隙率的控制机制。在树脂注射阶段对模具抽真空，而在模具填充和固化阶段通过本文设计的VARTM压力控制系统对模具加压。采用理论计算和模拟方法揭示树脂在多层介质中的面内、横向和三维流动模式。针对典型薄壁构件，研究了树脂在各向同性多孔介质中的渗透行为，阐明了纤维体积分数和孔隙率的控制机制。实验表明，改进的VARTM工艺显著提高了模具填充效率和复合材料性能。与常规VARTM工艺相比，面板厚度从1.7mm减少了4%，平均拉伸强度提高了7.3%，达到760MPa，平均弯曲强度保持在约720MPa，孔隙率从1.5%降至1%以下，纤维体积分数从55%提高到62%。
