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

这笔拨款为计算机模型的开发提供资金，以模拟纤维增强复合材料零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射成型软件相结合。在短纤维增强复合材料零件的制造过程中，模具填充对质量有重要影响，主要表现为纤维损伤、纤维过度取向、纤维干扰和纤维基体分离。目前的方法是基于模拟和试错技术。然而，为了正确处理光纤损伤、光纤干扰和光纤-基体分离，需要全面了解光纤运动背后的物理原理。在这个项目中，纤维使用机械方法建模，其中它们的结构被表示为由弹簧和珠子或圆柱体组合组成的柔性链。最终产品将允许工艺工程师在模具实际制造之前预测潜在的缺陷并优化零件的性能。模拟结果将包括最终的纤维方向，纤维磨损和纤维密度分布内的模塑部分。此外，这种工具将有助于揭示不太清楚的现象，例如纤维基质分离，导致肋骨和纤维含量低的特征，以及具有无纤维皮肤区域的注塑件。随着对成型过程中纤维运动现象的更高层次的理解，最终将有可能大规模生产具有更高质量和可控性能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，在汽车和航空工业需要能源效率和创新的时候。此外，这个项目的性质将为学生提供独特的机会，在各个领域获得跨学科的培训，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.