PSI - Issue 28

Haibao Liu et al. / Procedia Structural Integrity 28 (2020) 106–115 Liu H et al./ Structural Integrity Procedia 00 (2020) 000–000

108

3

(a) (b) Fig. 1. The schematics of (a) the round-nosed steel (RNS) impactor and (b) the flat-faced steel (FFS) impactor. 2.2. Composite specimens To manufacture the composite specimens, continuous carbon-fibre (T700) reinforced epoxy prepregs were employed to manufacture the composite laminates. The stacked T700/epoxy prepregs were cured in an autoclave provided by Beian Ltd, China. The curing jig and the curing cycle for the T700/Epoxy pre-pregs are shown in Fig. 2a and 2b, respectively.

(a) (b) Fig. 2. Diagrams of (a) the curing jig and (b) the curing cycle for the T700/Epoxy prepregs.

The composite panels were used to manufacture the composite specimens for the drop-weight impact experiments. The cured composites had a single-ply thickness of 0.125 mm and a laminate thickness of 3 mm. All the composite specimens had the same lay-up of [+45 3 /0 3 /-45 3 /0 3 ] S . The dimensions of the composite specimens were 150 mm × 100 mm, based on the ASTM 7316 standard (ASTM 2014). 3. Experimental procedures The drop-weight impact experiments were performed using an ‘Instron 9340’ drop-tower system, Fig. 3, provided by Instron CEAST, Italy. In the experiments, the round-nosed steel impactor was employed to strike the composite specimens at 15 or 45 J energy levels to determine the effect of impact velocity. The flat-faced steel impactor was