Análise do processo de dano em estruturas impressas 3D utilizando a técnica da emissão acústica

Abstract

Acoustic Emission Technique (AET) is a widely used non-destructive method for monitoring and analysing material failure. The technique is based on the detection of acoustic waves generated during the deformation or failure process of a material under stress. When a microcrack, crack or internal displacement occurs, the material releases energy in the form of elastic waves that are detected by sensors placed on the surface. This work aims to analyse the fracture process in 3D printed ABS beams with central notches and different internal fillings of 30%, 40% and 50% by applying AET during three-point bending tests. The aim was to understand how different filling levels affect the acoustic emission activity, damage evolution and the dominant failure mode. The technique not only allowed the number and intensity of acoustic events to be correlated with the percentage filling of the specimens, but also allowed the predominant failure mode to be identified and the crack propagation to be monitored using the b-value. It was shown that the number of acoustic events increased significantly in samples with lower filler content due to their lower structural strength. The predominant failure mode was tensile (Mode I), particularly in regions of higher stress concentration, although shear events (Mode II) were also recorded. TEA has proven to be a powerful tool for experimental analysis, providing valuable insight into the structural integrity and behaviour of 3D printed materials under mechanical loading. Keywords: Acoustic emission, 3D printing, ABS, b-value.