Multi-impact response of semicylindrical composite laminated shells with different thicknesses

Nowadays, composite materials are increasingly used in the most diverse areas of engineering, where non-planar geometries begin to be quite frequent. However, the existing knowledge about its mechanical performance is still not enough for structural applications. Therefore, experimental tests were carried out to study the thickness effect on static compression and multi-impact response of laminated E-glass/Polyester semicylindrical shells. For this purpose, specimen with thicknesses of 1.1 mm, 1.6 mm and 2.1 mm (corresponding to 6, 9 and 12 woven fabric layers) were considered. In terms of static response, higher thicknesses are responsible for higher compressive strength and stiffness, reaching, in the first case, differences of 252.6 % between the thinnest and thickest shells. Regarding the multi-impact response, the impact fatigue life increases 17.4 times for the analysed thickness range, which can be explained by the different damage mechanisms observed. It was observed that impact damage becomes more localized with increasing thickness, because the energy is dissipated by more interfaces.