Effect of ply-drops with gaps in tapered laminate

Abstract The Automated Fiber Placement (AFP) process shows great potential for efficient manufacturing of large composite structures. Although these technologies are widely used to produce large composite components, inconsistencies such as overlapping tapes or gaps between adjacent tapes may occur during the manufacturing. The combination of ply-drops with triangular gaps may cause a more severe strength knockdown. Within this study, modeling tools were firstly developed to automatically generate the ply-by-ply model with gaps and ply-drops based on the input ply books and dimensions for modelling the combination of ply-drops with triangular gaps. Then the comparison of the ply-drop + gap model with the specimens demonstrated that the cross-section views of the specimen can be well captured in the model and a good correlation was observed between model predictions. These tools have then been used to study and analyze the effect of ply-drop + gap in AFP manufactured tapered laminate composites, both the test and model results showed that the existence of triangular gaps at ply-drops reduced the strength further than the ply-drops only and the strength of ply-drop + gap model has a larger deviation from the test results than the ply-drop only model.