Effect of hygrothermal aging and ply-stacking sequence on low-velocity impact properties of CFRP composite plates

Abstract It is essential to obtain preliminary design data of composite marine vehicles operated in harsh marine environments, such as those with hygrothermal and impact effects. The effects of hygrothermal aging and stacking sequence on the low-velocity impact (LVI) response of carbon fiber epoxy composite plates (CFRP) were investigated experimentally. CFRP plates in six orientations [0°/90°/45°/−45°]s, [90°/45°/−45°/0°]s, [0°/90°/0°/90°]s, [90°/0°/90°/0°]s, [−45°/45°/−45°/45°]s, and [45°/−45°/45°/−45°]s (quasi-isotropic, cross-ply, and angle-ply) were manufactured using a vacuum-assisted resin infusion method. LVI tests were performed by using the Ceast 9350 Fractovis Plus impact machine. Four aging conditions (atmospheric, 2, 4, and 6 weeks aged) were simulated using Ascott CC 1000ip programmable salt spray and cyclic corrosion test chamber cabin. The effect of the ply-stacking sequence plays an important role in the failure of the top or bottom surface of the plate samples and dent depth. When 0-degree fiber is used on the upper and lower surfaces of the plates, the dent depth is lowest, followed by 90, +45, and −45°, respectively. Dent depth and top surface fiber cracking lengths generally decrease as the process begins with initial atmospheric conditions reaching 6 weeks.