Crack suppression in glass epoxy hybrid L-bend composites through drawdown coating technique using nano and micro fillers

Abstract

L-bend composite laminates are fundamentally weak against the crack growth in the through-thickness direction, particularly at the curvature region. To deal with this problem, an effort was made to suppress the crack growth by incorporating MWCNT, Al2O3, and SiC Micro fillers at the interface of unidirectional (UD) Glass fiber lamina, using a draw-down coating technique. The L-Bend Glass-Epoxy (GE) laminates were manufactured with the aid of a Hot pressing machine with a holding time being 10 min. The laminates were prepared with a manufacturing temperature of 130 °C and a pressure of 10 kg/cm2. GE curved laminates added with Nano and Micro fillers in the range of 0.5–2 wt% were manufactured. Four-point bending fixtures were designed and manufactured to facilitate the holding and loading of the specimen in the uni-axial tensile machine. Tests were conducted in accordance with ASTM D6415 and load-displacement plots were carefully recorded.GE laminates added with 0.5 wt% fillers greatly influence Curved Beam Strength (CBS) and interlaminar stresses for delamination as compared to pristine GE laminates. The laminates loaded with 0.5 wt% SiC exhibited higher interlaminar radial stresses (108.6 MPa) compared to other GE laminates.