This article concerns the experimental and numerical study of post-impact damage propagation in thin carbon/epoxy woven composite laminates loaded in fatigue tension. Low velocity normal drop weight impact tests are first performed. Post-impact fatigue tensile tests are then carried out. They are controlled in displacement. The monitoring is based on Digital Image Correlation and RX tomography. The influence of the impact energy and the tensile fatigue loading on the post-impact damage propagation is studied. The damage propagation is governed by matrix damage, with the emergence of tows/resin splittings and intra-tows crackings as well as delamination when the plies have different orientations. When the impact energy or the displacement level increases, the post-impact damage initiates sooner and propagate faster. In some cases, that can lead to a quasi-instantaneous failure identical to that observed for quasi-static tensile loading. The FEM based semi-continuous approach, initialy developped for the modelling of impact damage, is extended to fatigue loading for carbon/epoxy woven laminates. Fatigue damage laws, based on experimental observations are implemented. The modelling well correlates the experimental results in terms of damage propagation scenario and speed depending on the number of cycles for laminates made up of plies with the same orientation.

本文涉及在疲劳张力下加载的薄碳/环氧编织复合材料层压板冲击后损伤传播的实验和数值研究。首先执行低速正常落重冲击测试。然后进行冲击后疲劳拉伸试验。它们的排量受到控制。监视基于数字图像关联和RX断层扫描。研究了冲击能量和拉伸疲劳载荷对冲击后损伤传播的影响。损坏的传播受基质损坏的控制，当帘布层的取向不同时，会出现丝束/树脂开裂和丝束内部开裂以及分层现象。当冲击能量或位移水平增加时，冲击后破坏会更快地开始并传播得更快。在某些情况下，可能导致与准静态拉伸载荷相同的准瞬时失效。基于FEM的半连续方法最初是为冲击破坏建模而开发的，现已扩展到碳/环氧树脂编织层压板的疲劳载荷。疲劳损伤定律基于实验观察得以实施。该模型根据损伤传播的情况和速度很好地关联了实验结果，该速度取决于由具有相同方向的层组成的层压板的循环次数。根据实验观察得到实施。该模型根据损伤传播的情况和速度很好地关联了实验结果，该速度取决于由具有相同方向的层组成的层压板的循环次数。根据实验观察得到实施。该模型根据损伤传播的情况和速度很好地关联了实验结果，该速度取决于由具有相同方向的层组成的层压板的循环次数。