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 typical 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 research 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 limiting the area of delamination. However, using high cutting speeds avoid the delamination of materials, but leads to high production costs due to excessive tool wear.

Analysis of acoustic emission amplitude parameters when increasing the machining depth of a composite

“…In this case, it was pointed out that AE could be used in order to monitor damage to the tool and the treated surface. The strategy of applying AE to control a technological process of drilling the composite is examined in [5]. The algorithm for strategy implementation is based on the fact of relationship between the AE energy and the parameters of technological process.…”

Prediction of a delamination area during drilling of carbon composite laminates structures

“…It is also revealed that the relation between the delamination area, the feed rate and the cutting speed is given as A d = Kƒ α t b (Andoh, 2005), where K, α and β are constants and depend on the material used. These constants need to be studied together with the drilling time at onset of delamination instead of the remaining drilling time (Andoh et al, 2010). An on-line technique may also account for the anisotropic nature of the material.…”