Resumo:
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.
