PSI - Issue 71

Gaurish S. Vaze et al. / Procedia Structural Integrity 71 (2025) 395–400

396

The specimen used for ballistic impact testing was fabricated using composite materials, Carbon f iber and E-glass through the vacuum bagging process. This method applies mechanical pressure during curing to compact fibre layers, eliminates trapped air, and reduces internal porosity and voids. Vacuum bags, made of rubber-coated fabric or polymer film, are used along with a breather layer and a release barrier to ensure uniform vacuum distribution. Based on the application, the vacuum bag may fully enclose the laminate or cover only the outer face. The open end is sealed, and air is evacuated using a vacuum pump. The composite laminate was initially cut to dimensions of 200 mm × 200 mm. Peel ply, perforated film, breather material, and the vacuum bag were cut at least 5 cm larger than the laminate. The base plate was cleaned with acetone and coated with a release agent. Epoxy resin and hardener were mixed in a 10:1 ratio and applied layer by layer using a nylon brush, starting with the first fibre layer. Once all layers were stacked, peel ply, perforated film, and breather were placed on top. Mastic sealant was applied around the laminate, leaving space for the air valve. A hole was made in the vacuum bag for the valve, which was then sealed in place. After checking for leaks, the valve was connected to a vacuum pump to draw out air. The setup was left to cure for 24 hours. After curing, the vacuum bag, breather, perforated film, and peel ply were removed. The composite was gently detached using a chisel and mallet, cleaned, and cut to the final required dimensions. The schematic of the fabrication process is shown in Fig. 1.

Fig.1. Schematic of Fabrication Process of specimen

The actual fabrication process followed (Fig.2) for the specimen is shown

Fig. 2. Schematic of Fabrication Process of specimen

The final composite sample is also shown (Fig.3).

Fig. 3. Fabricated specimen of Carbon Fibre and E-glass composite