Research Planning Grant: Conformability of Fiber Preform Architectures

本研究的目的是确定纤维预制体的结构对其与某些零件形状（例如，角落，曲线）的一致性的影响。纤维预成型的使用可以显著地打开中到大批量复合材料市场，因为它有可能生产成本效益高、结构合理、接近净形状的部件。然而，复杂的零件形状可能导致纤维排列方向不在最大载荷方向的区域。此外，纤维的移动会导致纤维体积分数低的区域产生薄弱点。这两种变化往往发生在应力集中的区域，导致低于预计载荷能力的失效。该项目将研究几种测量预成型变形（例如拉伸、剪切和弯曲行为）的方法，包括使用光学和图像分析技术、示踪纤维和各种负载配置模拟加工条件。预计这项初步工作将导致更详细的研究，从而量化排列、双轴和随机纤维垫的变形响应。通过了解不同纤维垫几何形状的变形行为，可以预测各种预制体结构对加工条件的响应，从而优化以适应所需的零件形状。详细了解纤维垫的性能对于复合材料在“大众市场”应用领域的广泛使用至关重要，特别是在汽车行业。

The objective of this research is to determine the effect of the structure of a fiber preform on its conformability to certain part shapes -- e.g., corners, curves. The use of fiber preforms can significantly open up the medium to high volume composite markets due to its potential to produce cost-effective yet structurally sound, near net shape parts. However, complex part shapes can result in regions where the alignment of fibers is not in the direction of maximum loading. In addition, fiber movement can result in regions of low fiber volume fraction leading to weak spots. Both of these variations tend to occur in areas where stress concentrations are also a concern, resulting in failures below projected loading capacity. The project will investigate several methods of measuring preform deformation (e.g., tensile, shear, and bending behavior) -- including the use of optical and image analysis techniques, tracer fibers, and various load configurations simulating processing conditions. It is expected that this preliminary work will lead to a more detailed study resulting in the quantification of the deformation response of aligned, biaxial, and random fiber mats. By understanding the deformation behavior of different fiber mat geometries, the response of various preform architectures to processing conditions can be predicted and thus optimized to fit the desired part shape. A detailed understanding of the behavior of fiber mats is essential to the widespread use of composite materials in the "mass market" application areas, particularly in the automotive industry.