Processing Fundamentals and Process Modification for Rapid Liquid Molding of High-Performance Composites

小行星9522801 采用树脂传递模塑等工艺的液体模塑是一种以合理的成本制造相对大量的复杂、高性能复合材料产品的方法。 液体成型成功的关键是用树脂均匀和完全地填充封闭和通风的模具。 由于模具内部是复合材料预制件和插入件的迷宫，因此流动渗透率难以建模和预测。 该项目使用分形的分析和实验研究作为描述孔隙结构的一种方式。 这允许计算模具内的渗透率。 通过曲折长度和毛细管尺寸的分形模型，可以使用达西定律确定渗透率，因此可以使用现有的数值代码计算封闭模具中的流动。 验证这种方法的实验装置使用三部分树脂玻璃模具，和视频和图像处理系统来记录流动模式，并确定复合材料垫的分形维数。 使电流通过作为预制件的一部分的导电纤维是一种工艺创新，将对其进行研究以提高固化的均匀性。 这项研究的影响将是改进通风系统的设计和液体复合材料成型工艺中的均匀填充，从而降低成本，并为这些高性能材料的使用提供更多机会。 ***

9522801 Pitchumani Liquid molding with processes like resin transfer molding, is a way to fabricate relatively high volumes of complex, high performance composite products at reasonable costs. A key to the success of liquid molding is uniform and complete filling of a closed and vented mold with resin. Because the inside of the mold is a labyrinth of composite preforms and inserts, the flow permeability is difficult to model and predict. This project uses an analytical and experimental investigation of fractals as a way to describe pore structure. This allows calculation of the permeability inside the mold. With fratal models for the tortuous length and capillary size, the permeability can be determined using Darcy's law so the flow in the closed mold can be calculated using existing numerical codes. An experimental setup to verify this approach uses a three-part Plexiglas mold, and a video and image processing system to document the flow pattern and determine the fractal dimensions of the composite mat. Passing a current through conductive fibers that are part of the preform is a process innovation that will be investigated to improve the uniformity of curing. The impact of this research will be improvements in the design of venting systems and uniform filling in liquid composite molding processes, leading to lower costs and more opportunities for use of these high performance materials. ***