Abstract
Composite materials have been widely used in aerospace, electrical vehicles and sports goods. The delamination occurs when drilling the composite materials parts for assembly, which leads to serious concerns of reliability and safety. How to reduce delamination is a major issue in drilling composites. This research presents a method of utilizing back-up mechanism which places a supporting block mades of carbon steel in the middle of the tube to reduce the delaminations caused by twist drilling. Increasing stiffness of back-up mechanism can also reduce delamination. The experimental results demonstrate that drilling feed rate can be elevated 300% and spindle rotating speed can be elevated to 200% when maintaining the same level of delamination extent. After Increasing stiffness of back-up mechanism, the delamination extent can be reduced up to 35%.