Damage investigation in drilling of glass fiber reinforced plastic composite laminates

Machining of fiber reinforced plastic is a process that is substantially different from metals. The inherent anisotropy in the material system makes the material removal mechanism quite complex. Drilling composite materials is necessary to ascertain the structural integrity of intricate composite products. Drilling of laminated structures results in extensive damage around the drilled hole. This study is an attempt to quantify and propose mathematical models for drillinginduced damage in terms of the cutting speed and the feed speed. Mathematical models have also been proposed for the resulting thrust force and the torque. Four different drill point geometries, namely 4-faceted, 8-faceted, parabolic, and Jodrill, are investigated in this study.