Drilling of Fiber-Reinforced Plastics - Tool Modeling and Defect Prediction

Fiber reinforced polymer (FRP) composites have been steadily replacing metals as choice engineering materials for various applications. Although FRPs can be manufactured to near-net shape, post processing operations such as machining are required to create some features (such as holes). In order to drill holes efficiently with the least waste and defects, it is essential to understand the machining behavior of FRPs. As FRPs are multiphase materials with complex load-response behavior, there is a need to turn to analytical and numerical approaches to fully understand the machining process. This report discusses a model to analytically estimate the edge defect in drilled FRP laminates. The model predicts that increasing drilling thrust force causes greater delamination and thus, greater edge defects. The report also discusses a tool which can create automated 3D CAD drill models based on geometric as well as manufacturing parameters. This tool is a required component of numerical/FE-models of FRP drilling. The tool outputs the drill in a variety of solid geometry formats which can then be meshed and used in different FE analysis packages.