Abstract The ability to predict wrinkles and prevent them during the forming process is highly desirable for process design in industrial environments. This ability to predict requires a multifaceted characterization of textile reinforced composites, material properties and implementation in forming simulations. The deformation mechanisms during the actual forming process are coupled, implying that the coupled shear, tension, friction, and bending modes of prepreg ply could lead to a change in the effective material properties. Consequently, this paper studies the coupling effect of shear and ply-ply friction on bending properties during the forming process. A series of experimental approaches for providing the required information on those combined properties is presented. Moreover, a systematic approach for a finite element (FE) prediction of bending behavior, considering such coupling effect, is developed. The combination of numerical results and experimental observations demonstrates the significance of considering these coupled deformation modes to yield meaningful outcomes in future forming simulations. Simultaneously, this study provides fundamental knowledge on how the bending stiffness of uncured prepreg is influenced by the sample's shear angle and the friction between plies.

中文翻译：

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聚合物复合材料成型过程中耦合特性的表征和有限元建模

摘要 在成型过程中预测和防止皱纹的能力对于工业环境中的过程设计是非常需要的。这种预测能力需要对纺织增强复合材料、材料特性和成形模拟的实施进行多方面的表征。实际成型过程中的变形机制是耦合的，这意味着预浸料层的剪切、张力、摩擦和弯曲模式的耦合可能导致有效材料性能的变化。因此，本文研究了在成形过程中剪切和铺层摩擦对弯曲性能的耦合效应。介绍了一系列实验方法，用于提供有关这些组合属性的所需信息。而且，考虑到这种耦合效应，开发了一种用于弯曲行为的有限元 (FE) 预测的系统方法。数值结果和实验观察的结合证明了考虑这些耦合变形模式以在未来的成形模拟中产生有意义的结果的重要性。同时，该研究提供了关于未固化预浸料的弯曲刚度如何受样品剪切角和层间摩擦影响的基础知识。