Effect of point geometry and their influence on thrust and delamination in drilling of polymeric composites

Polymeric composites are recognised as better materials for structural components due to their inherent properties. However, they introduce several kinds of damages while creating holes for assembly. Of these, delamination is considered as the most serious damage since it reduces service life of the component. Thrust is an important factor which contributes for delamination. Thrust and correspondingly delamination can be controlled by proper drill point geometry. The aim of this work is to study the influence of point geometry on thrust and delamination. Drilling tests were carried out on glass fibre reinforced plastics using carbide drills with different point geometries. Delamination is evaluated through ultrasonic ‘C’ scanning. The results shows that drill point has considerable influence on thrust and delamination and tripod point geometry produce the least delamination damage.