玻纤/环氧树脂复合材料VARTM成型工艺仿真及实验

针对真空辅助树脂传递模塑(vacuum assisted resin transfer molding,VARTM)工艺成型玻纤/环氧树脂复合材料存在气泡、聚胶等问题,采用PAM-RTM软件对该复合材料的VARTM成型工艺进行模拟仿真。通过改变流道的设计方案,控制树脂黏度,观测充模过程中树脂的压力分布及充模时间,优化实验工艺,进而对模拟结果进行实验验证。结果表明:最佳注射方案是平行于Y轴一侧线性注入,另一侧线性排出。多线性注射虽然可以提高效率但是同时会出现交汇、聚胶等现象。充模时间随树脂黏度的增加而增加,随着充模过程的进行,黏度过高的树脂会发生部分固化,影响纤维的浸润。因此,树脂黏度控制在0.5 Pa·s左右较为合适。根据模拟优化结果,采用VARTM工艺分别制备2种典型的玻纤/环氧树脂复合材料。发现最佳注射方案,制备的复合材料表面光滑,无明显气泡、聚胶等缺陷,注射方案较好。

Simulation and experiment of VARTM filling process for glass fiber/epoxy resin composites

To solve the problems of bubbles and coagel in vacuum-assisted resin transfer molding for glass fiber/epoxy resin composites,PAM-RTM software was employed to simulate the VARTM molding process of composites,and then process optimization was made by redesigning scheme of the flow channel,controlling viscosity of resin,observing pressure distribution and filling time of the resin during the filling process;thus the resultant simulation was verified by experiments.The results show that the linear injection paralleling to the Y-axis side,and the linear discharge on the other side present the optimal injection.Although multi-linear injection could improve the efficiency,it also caused the intersection and lack of glue.The filling time increasedrose viscosity of the resin.While if the viscosity of the resin was too large,the resin would partially solidify and thus affect the infiltration of the fibers.The suitable resin viscosity is about 0.5 Pa·s.In view of the simulation optimization results,the typical glass fiber/epoxy composite samples were prepared by VARTM process.The morphology of the samples revealed smooth surface and no defects like obvious pores and coagels.Such above results presented optimal injection solution,linear injection paralleling to the Y-axis side and linear ejection on the opposite side.