Issue 42

G. Bolzon et alii, Frattura ed Integrità Strutturale, 42 (2017) 328-336; DOI: 10.3221/IGF-ESIS.42.34 328 Failure analysis of thin metal foils G. Bolzon, M. Shahmardani Politecnico di Milano, Department of civil and environmental engineering, Italy Gabriella.bolzon@polimi.it, Mahdieh.shahmardani@polimi.it R. Liu, E. Zappa Politecnico di Milano, Department of mechanical engineering, Italy Rui.liu@polimi.it , Emanuele.zappa@polimi.it A BSTRACT . The mechanical response and the failure mode of thin metal foils under tensile load has been analyzed supplementing the usual test records with full-field measurements performed by three-dimensional digital image correlation (3D DIC) techniques. The experiments have been simulated by finite element models formulated within a non-linear continuum framework. The study presented in this contribution concerns symmetrically pre-cracked aluminum samples. The wrinkling of the specimens during the test and the possible and alternative failure mechanisms are evidenced and discussed. K EYWORDS . Thin metal foils; Failure analysis; Digital image correlation; Numerical simulation. Citation: Bolzon, G., Shahmardani, M., Liu, R., Zappa, E., Failure analysis of thin metal foils, Frattura ed Integrità Strutturale, 42 (2017) 328-336. Received: 08.08.2017 Accepted: 24.08.2017 Published: 01.10.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he present study is motivated by the spreading application of thin metal foils in different technological fields, for the production of flexible electronics, nano or micro-devices and beverages packaging [1-3]. The thinness of these laminates (few microns or less) makes them behave differently from the corresponding bulk materials. In particular, the apparent brittleness increases as the metal thickness is reduced [4-6]. Determining the actual material properties and fracture characteristics of thin foils may be rather problematic since the samples are difficult to handle and sensitive to local imperfections, size and geometric effects. In these conditions, even the interpretation of the output of uniaxial tensile tests may be difficult [7, 8]. Alternative loading procedures [9] and full-field displacement monitoring combined with the simulation of the experiment [10, 11] have been suggested to overcome some limitations of the most commonly employed parameter calibration procedures. Different numerical approaches have been proposed in the present context [12, 13]. This study focuses on the mechanical response of thin aluminum (Al) samples leaded to failure under uniaxial tensile load. Symmetrically cut edge notches induce crack propagation in a pre-fixed location. The displacement distribution and the T