Study of high performance hybrid laminates based on a thermoplastic matrix

This study focuses on the feasibility of using scale model tests for predicting the full-scale behavior of fiber-metal laminates (FMLs) based on ply level scaling supported by mechanical tests in tension and flexure. Two laminates were studied namely, [Al_n 0°/90°_n] _s and [Al_n +/- 45°_n]_s. The materials were based on an aluminum alloy, a self-reinforced polypropylene composite and a polypropylene film acting as an interlayer adhesive. This investigation follows a series of studies undertaken previously by different authors primarily on epoxy systems in which scaling effects were observed. Ply-level scaling was used to scale four different sample sizes (n = 1/4, 1/2, 3/4 and full scale). Special attention focused on the mechanical properties for which evidence of scaling was sought such as changes in stiffness, strength, strain to failure, the first ply failure threshold and the stress/strain response. In general, a small decrease in the value of these parameters was observed with increasing specimen size.