DEVELOPMENT OF A CONTROL STRATEGY FOR MONITORING THE DELAMINATING DAMAGE IN DRILLING OF CARBON COMPOSITE LAMINATES

Abstract

Composite materials have attractive features, such as high strength to weight ratio and high stiffness to weight ratio. However, they are easily damaged during machining operations. A typi- cal damage is delamination, which can occur when fiber reinforced composite laminates are drilled. Control of delamination is critical for the utilization of composite materials. This re- search seeks to develop a technique to control inter-ply delaminations during the drilling of laminated composites. A statistical factorial design technique is used to develop a model that relates the feed rate, cutting speed, and tool size to the acoustic parameters. A control algorithm is built from the model. The algorithm is used to modify the instantaneous feed rate in order to maintain the acoustic energy below a threshold value. This control strategy is effective in limit- ing the area of delamination. However, using high cutting speeds avoid the delamination of ma- terials, but leads to high production costs due to excessive tool wear.