Transport Phenomena and Microstructure Development in Thermoplastic Composites Processing

在快速和连续生产的情况下， 纤维缠绕和拉丝，目标是获得高的 具有均匀树脂浸渍的纤维的体积分数， 一种结合良好且无空隙和残余物的结构 压力 因此，树脂浸渍在非- 在等温条件下，聚合物在膜上的质量扩散 浸渍纤维束的界面及其变化 结构固化时的结晶度是 这类复合材料的加工。 这项研究将 发展对运输机制的系统理解 质量，动量和能量的连续变形 排列纤维的各向异性多孔介质，并检查其 相互作用，并估计其相对重要性。 然后这可以 集成到过程模型中，以便计算 纤维体积分数、空隙率和残余应力， 制造工艺、材料形式和 加工条件 该方法将涉及模型 在严格控制的实验室条件下进行的实验研究， 这将有助于识别和理解流动的物理学， 剪切稀化粘性流体，并将形成基础 理论建模 同时，交通的作用 微观层次的方程 将探索各向异性介质的代表。 的 目的是开发一个宏观的过程模型， 将纤维体积分数， 不同材料的孔隙率和残余应力分布 形式和加工条件。 以确定有效性和 制定的过程模型的有用性，实际实验 包括纤维缠绕的加工环境， 将采用纸浆加工技术。 该研究将使生产更均匀，高 由复合材料制成的强度部件。

In rapid and continuous manufacturing situations such as filament winding and pultrusion, the goal is to obtain a high volume fraction of the fibers with uniform resin impregnation and a structure that is well bonded and free from voids and residual stresses. Hence, the mechanics of resin impregnation under non- isothermal conditions, the mass diffusion of the polymer across the interfaces of impregnated fiber bundles and the changing crystallinity as the structure solidifies are key phenomena during the processing of such composite materials. This research will develop a systematic understanding of the mechanisms of transport of mass, momentum and energy in a continuously deforming anisotropic porous media of aligned fibers and examine their interactions and estimate their relative importance. This can then be integrated into process models which will allow calculation of the fiber volume fraction, void fraction and residual stresses as a function of the manufacturing process, material form and processing conditions. The approach will involve model experimental studies in carefully controlled laboratory conditions, which will serve to identify and understand the physics of flow of shear thinning viscous fluids and will form the basis for theoretical modeling. Simultaneously, the role of transport equations at the microscopic level in a cell geometry representative of the anisotropic medium will be explored. The intent being to develop a macroscopic process model based on microscopic analysis that will relate the fiber volume fraction, void content and residual stress distribution of different material forms and processing conditions. To establish the validity and usefulness of the formulated process models, experiments in actual processing environment encompassing of filament winding and pultrusion processing techniques will be carried out. The study will allow the production of more uniform, high strength components from composite materials.