Analysis of milling in composite material by non-destructive methods

Abstract

In aerospace industry, composite materials offer several advantages, such as high weight-to strength ratio and corrosion resistance. Aerospace materials are costly and have high safety standards, frequently using non-destructive testing in order to evaluate the material without incurring in further damage. Acoustic emission is a non-destructive testing method, which allows the signal processing to evaluate material performance during mechanical tests for determining material defects, for example. This study focused in the machining process of composite plates, in terms of surface finishing evaluation with comprehension of process phenomenology using non-destructive testing. Manufacturing processes are complex, especially the machining of composite materials, due to their specific properties and characteristics. The detection and prediction of surface finishing and occurrence of defects during manufacturing using non-destructive techniques is industrially useful, in terms of increasing automated manufacturing systems to increase productivity and quality control. The aim of this study is to show the possibility of online monitoring of the cutting process and to understand mechanism behind variables of control, with comparisons of different milling parameters and focusing in their impacts in acoustic emission signals, infrared thermography and surface finishing. The results indicates the relationship between cutting process and acoustic emission signals, with a key differentiation of other studies because it shows the not only the capability of detecting anomalies during cutting process and to predict surface quality by acoustic emission signal analysis, but also that is possible to develop new methods of monitoring in real time machined surface of composite parts quality using acoustic emission signals.