Processing of nanoclay filled sandwich composites and their response to low-velocity impact loading

In this study, sandwich panels were fabricated with neat and nanophased foam cores and 3-layered plain weave carbon fabric/SC-15 epoxy-nanoclay composite face sheets. Neat and nanophased foam cores with Nanocor® I-28E nanoclay at a loading of 0.5% and 1% by weight were prepared. Sandwich panels were then fabricated using co-injection resin transfer molding process. The facesheets were made by infusing SC-15 epoxy containing 1% and 2% by weight of nanoclay into 3 layers of plain weave carbon fabric. Samples of size 100 × 100 mm were then cut from the panels and subjected to low-velocity impact loading using an instrumented impact test setup. Impact response of the samples was recorded and compared. The tested samples were then sectioned into two halves and scanned using a scanner, optical and scanning electron microscopes to understand the failure patterns. Samples with nanophased foam sustained higher loads and had lower damage areas as compared with neat counterparts. Nanophased foam cores exhibited brittle fracture.