Effect of stacking sequence on the double‐point low velocity impact response and compression‐after‐impact behavior of glass fiber‐reinforced composite laminates

Abstract The double‐point low velocity impact response and compression‐after‐impact behavior of composites were explored in terms of the influence of lay‐up sequences in this paper. Three representative laminates, [0° 2 /90° 2 ] s cross‐ply, [±45°] 2s angle‐ply and [0°/−45°/45°/90°] s quasi‐isotropic laminates were studied. Each laminate was impacted at two points with the same distance from the center sequentially. The force‐time/displacement and energy‐time histories were compared according to the various damage modes induced in the laminates at four different impact distances. The changes of the mechanical features including peak force, maximum displacement and absorbed energy were further analyzed. Results showed that the impact responses and damage characteristics were affected by the stacking sequence and impact distance. The differences of the impact mechanical characteristics decreased with the impact distance increasing because of the reduction of damage interference between the two impacts. The [±45°] 2s laminate possessed the best impact resistance compared to the [0° 2 /90° 2 ] s and [0°/−45°/45°/90°] s laminates. Furthermore, the compressive load–displacement response and the residual strength of the three kinds of laminates were compared. The compressive failure mode was analyzed by the damage morphology and strain history. It was found that the [±45°] 2s laminates retained the highest CAI strength. A brittle compressive failure behavior was observed for the [0° 2 /90° 2 ] s and [0°/−45°/45°/90°] s laminates. However, the compressive failure behavior for the angle‐ply laminates changed from plastic failure to brittle failure with the impact distance increasing. Highlights The double‐point impact behavior is affected by the stacking sequence. The [±45°] 2s angle‐ply laminate has the best resistance to impact. The changes of impact responses decrease as the impact distance increases. The CAI strength decreases with the impact distance increasing. The angle‐ply laminate shows a plastic failure behavior at low impact distances.