An asymmetric FRP laminate with a circular precrack to determine impact‐induced damage

Abstract An asymmetric laminate is employed to study impact‐induced damage of subpenetration experiments. The configuration of the asymmetric laminate is chosen to have its stiffness characteristics almost identical to those of a symmetric laminate. The impact is made with a mild steel striker to have impact energy close to 12 J and impact velocity close to 50 m/s. A circular precrack is also introduced to facilitate failure on the midplane of a laminate. Due to material discontinuity at the midplane the damage area extension (DAE) of the precrack is found to be 1.83 cm ² on asymmetric laminates against 0.73 cm ² on symmetric laminates. Impact experiments are also conducted on bonded GFRP specimen with Epibond 1590 A/B adhesive using asymmetric laminates. DAE of adhesive interface is found to be substantially smaller than DAE of interlaminar failure. DAE of adhesive interface is further reduced when the adhesive is modified with 7.5% XNBR. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers