Experimental investigation the drill bit curve radius & chisel point on effect of induced damage in drilling woven GFRP

The purpose of this study was to find experimentally the effects of concave and convex major cutting edge (Helical & Recon point) and chisel point on the drilling of composite. Due to composite materials are natural orthotropic, so gradually these materials are substituted by some metals such as steel that are used in manufacturing automobile and aerospace and other industries. Because of increasing composite's utilization in industries, it is necessary to stabilize and set standards of machining parameters. Drilling is the main machining operation in producing process for assembled the composite work piece. So the quality of drilling hole should be considered to avoid snapping mechanical structure. Tool geometry is one of the most important factors in the drilling process. If it is neglected, the thrust forced increase, and it causes damage around the hole such as delamination, large entrance and exit burr, and induced cracks. The most damaging in drilling FRP is delamination of the composite's lamina that occurs when drill bit is entered and exited. In the other hand, this study used ANSYS finite element software to determine the value of stress in composite plate and use to analyze for designing the jig & fixture in this drilling process. In conclusion, with comparing delamination, the best geometry tool introduced for the lowest amount of damage. © (2014) Trans Tech Publications, Switzerland.