Identification of damages into a polymer structure by AE - transition from tensile specimen to structure


This paper aims to study the damage mechanisms with acoustic emission technique (AE) in a polymer sandwich structure that contains three layers: two polyethylene skins and the polyethylene foam core (skin-foam-skin). First, a classical tensile test was carried out to correlate the acoustic signals with plasticity initiation and damage of a polyethylene sample. The results obtained are similar to those observed in other studies. Moreover, it is possible to separate the signal due to cavitation from the signal due to necking propagation. In a second step, the technique is used to detect the rupture of a polymer skin on a rotomolded skin-foam-skin structure (bottle). Tests were performed on this bottle by applying internal water pressure. Two tests are conducted with interruptions more or less early to determine the first damages and understand their evolution. Finally, different parameters (average frequency, RA value, etc.) are measured to understand and quantify the perceived damage. A structural damage scenario is proposed based on the AE/RX correlation and the mechanical behavior.
