Author(s): Kharrat, Fatma ; Chaari, Rania ; Khlif, Mohamed ; Hilliou, L. ; Covas, J. A. ; Haboussi, Mohamed ; Bradai, Chedly
Date: 2023
Persistent ID: https://hdl.handle.net/1822/87626
Origin: RepositóriUM - Universidade do Minho
Subject(s): Bulge test; Construction; Digital image correlation; Biaxial characterizatio; PLA films; Strain field distribution; 3D digital image correlation (3D-DIC); biaxial characterization; mechanical behavior; polymer films
The bulge test is a versatile mechanical testing technique that can be used for a wide range of of applications in materials science, engineering, and biomedical research, and is a valuable tool for understanding the mechanical behavior of materials and structures. In this present work, the construction of a pneumatic bulge test apparatus dedicated to characterizing 50 micrometers-thick PLA films was detailed. The bulge cell was designed to be large enough to take into account the impact of the film thickness instability on the mechanical properties. For instance, PLA films were characterized through the bulge test and the corresponding properties was compared to the uniaxial ones. Compared to traditional strain measurement techniques, 3D-DIC offers superior accuracy, precision, and non-destructive testing capabilities, making it a more reliable option for deformation measurement. This technique was used for defect detection such as cracks, voids, and delaminations in materials and structures.is an emerging application of this measurement technique. In this work, 3D-DIC was used during bulge testing in order to analyze the evolution of the strain field within the test sample and to locate film thickness reduction. It was found that PLA film exhibits zones with strain concentration located within bands parallel to the machine direction of the film which are suggested to be zones with reduced thickness.
