Analytical model for pre-drilled thick composite plates

摘要

In aeronautical, the machining of composite materials is more and more used. Drilling is in particular the most used process in the assembly of aeronautical structures. When drilling composite materials, delamination occurs at the exit of the hole. These defects diminish the strength of the structure to failure. To minimize delamination, drilling process with pilot hole is used. In this paper, analytical model for drilling thick composite structures with pilot hole using a twist drill is proposed. This model predicts the critical thrust force at delamination. Different hypothesis of boundary conditions and external loading are proposed. Punching tests with twist drill are realized in order to select the corresponding hypothesis of boundary conditions and external loading. These results may be used to optimize the cutting conditions when drilling thick composite plates with pilot hole.