Modeling Fiber-Matrix Separation and Fiber Jamming During Processing of Fiber Filled Composites

这笔赠款为开发计算机模型提供资金，以模拟纤维增强复合材料部件在制造过程中的行为，并将新模型与现有的商业压缩和注塑软件相结合。在短纤维增强复合材料制件的制造过程中，充型对制品的质量起着至关重要的作用，主要表现为纤维损伤、纤维取向过度、纤维堵塞和纤维基质分离。目前的方法是基于模拟和试错技术。然而，为了正确处理纤维损伤、纤维堵塞和纤维-基质分离，需要对纤维运动背后的物理原理有全面的了解。在这个项目中，纤维使用机械方法建模，其结构被表示为由弹簧和珠子或圆柱体的组合组成的柔性链。最终产品将允许工艺工程师在实际制造模具之前预测潜在缺陷并优化部件的性能。模拟结果将包括最终纤维取向、纤维磨损和纤维密度在成型零件内的分布。此外，这样的工具将有助于揭示不太了解的现象，例如纤维基质分离，导致肋条和特征具有低纤维含量，以及注射成型零件具有无纤维蒙皮区域。随着对成型过程中纤维运动现象的更高水平的了解，在汽车和航空工业需要能效和创新的时候，最终将有可能大规模生产质量更高、性能可控的聚合物复合材料部件，使轻质聚合物复合材料可用于更广泛的应用。此外，该项目的性质将为学生提供在不同领域获得跨学科培训的独特机会，包括材料科学、聚合物复合材料工程、系统科学和制造。

This grant provides funding for the development of computer models to simulate the behavior of fiber reinforced composite parts during the manufacturing process and to couple the new models with existing commercial compression and injection molding software. During the manufacturing of short fiber reinforced composite parts, mold filling plays a significant role in the quality, reflected by fiber damage, excessive fiber orientation, fiber jamming and fiber matrix separation. Current approaches are based on simulation as well as trial and error techniques. However, in order to properly deal with fiber damage, fiber jamming and fiber-matrix separation, a comprehensive understanding of the physics behind fiber motion is required. Within this project, the fibers are modeled using a mechanistic approach, where their structure is represented as a flexible chain composed of a combination of springs and beads or cylinders.The final product will allow the process engineer to predict potential defects and optimize the properties of a part before a mold is actually made. Simulation results will include final fiber orientations, fiber attrition and fiber density distributions within a molded part. Furthermore, such a tool will help shed light on phenomena that are not well understood, such as fiber matrix separation, that result in ribs and features with low fiber content and in injection molded parts with a fiber free skin region. With a higher level of understanding of fiber motion phenomena during molding, it will eventually be possible to mass produce polymer composite parts with higher quality and controlled properties, making lightweight polymer composites available to a wider range of applications, at a time when energy efficiency and innovation are needed in the automotive and aeronautical industries. Furthermore, the nature of this project will provide students the unique opportunity to obtain interdisciplinary training in various fields including material science, polymer composites engineering, systems science, and manufacturing.