Composite materials are increasingly used in the aeronautical field. The assembly of structures requires usually drilling of composite parts. Drilling of composite materials generates defects, mainly delamination at the exit of the hole. This major defect diminishes the structure strength. Delamination is directly related to the drilling thrust force. Minimizing this force reduces the defects. Adding a woven glass ply at the exit of the hole is found to be another adequate solution to reduce the defects. In this paper, the drilling of carbon/epoxy thick composite structures with a woven glass ply at the exit of the hole is considered. An analytical model is developed to determine for a given tool geometry the critical delamination forces as function of the number of non-drilled plies remaining beneath the tool. The results are validated experimentally. These results show that adding a woven glass ply at the exit of the hole reduces delamination.

复合材料越来越多地用于航空领域。结构的组装通常需要对复合零件进行钻孔。复合材料的钻孔会产生缺陷，主要是在孔的出口处分层。该主要缺陷降低了结构强度。分层与钻进推力直接相关。最小化此力可减少缺陷。发现在孔的出口处添加玻璃编织层是减少缺陷的另一种适当的解决方案。在本文中，考虑了在孔的出口处用玻璃编织层对碳/环氧厚的复合结构进行钻孔。开发了一种分析模型，以确定给定工具几何形状的临界分层力，该临界分层力是剩余在工具下方的非钻孔层数的函数。实验验证了结果。这些结果表明，在孔的出口处添加玻璃编织层可减少分层。