Experimental study of compression after impact of asymmetrically tapered composite laminate

This paper presents an experimental study of CAI (compression after impact) of tapered composite laminate. Two types of layup with thickness changing from 4 mm to 6 mm are considered. A new CAI testing rig, suitable for the specimens and a brief description of impact damage are presented first. Then, the behavior of impacted specimens under compressive loading is discussed along with the effects of ply drop-off parameters (taper angle, ply drop-off disposition and configuration) and impact point location on the failure mechanism. Finally, the residual strength in CAI of tapered laminates is compared with equivalent flat laminates. The results show that compressive behavior of the specimens is mostly governed by a coupling between compression and bending, generated by the discontinuity of the neutral axis in the tapered region. Despite this difference of behavior with flat laminates, the presence of ply drop-off has little effect on the residual strength in CAI.