The freedom of composite design can be improved by combining continuous and discontinuous prepregs. The forming of a pre-heated blank made of optimally oriented and distributed discontinuous prepreg plies may lead to unacceptable defects such as in-plane and out-of-plane wrinkles, sliding of plies over long distance, rotation of adjacent plies, bending of fiber induced by transverse squeeze flow and finally to inappropriate and inefficient fiber distribution. This arises because the individual discontinuous plies are free to move and deform in the mold during the forming step. First, this paper presents some experiments conducted to identify the behavior of a stack of unidirectional discontinuous viscous prepregs subjected to through-thickness compression. Then a model based on a heterogeneous anisotropic fluid approach is gradually developed in accordance with the experimental findings. It is shown that the various observed phenomena are retrieved by the numerical model and that the predicted values are in good agreement with measurements, but also that it requires to be solved in 3D with a relatively fine mesh in the thickness to provide good results.

通过组合连续和不连续的预浸料，可以提高复合材料设计的自由度。由最佳取向和分布的不连续预浸料片制成的预热坯料的形成可能导致不可接受的缺陷，例如面内和面外皱纹，层间长距离滑动，相邻层的旋转，纤维弯曲由横向挤压流引起，最终导致纤维分布不适当和效率低下。这是因为各个不连续的层在成型步骤中在模具中自由移动和变形。首先，本文介绍了一些实验，以鉴定经过厚度方向压缩的一堆单向不连续粘性预浸料的性能。然后根据实验结果逐步建立了基于非均质各向异性流体方法的模型。结果表明，通过数值模型可以检索到各种观察到的现象，并且预测值与测量值非常吻合，但是还需要在3D中使用厚度相对较细的网格对其进行求解以提供良好的结果。