Influences of wrinkles induced by tows’ offset in automated fiber placement on the bending properties of composites

• Using the offset distance of the tow as the variable of the wrinkle defect. • Establishing a complete recognition algorithm for extracting wrinkle contours. • Quantifying the influences of wrinkles by the wrinkle smoothness S. This paper studies the influence of wrinkles caused by tows’ offset on the bending performance of composite laminates during Automated Fiber Placement (AFP) manufacturing. In this paper, the different distances of tows’ offset are set to prepare laminates containing various wrinkles and obtain the characteristics of different wrinkles through the feature recognition algorithm. Then a three-point bending test is conducted to investigate the influences of different wrinkles on the flexural strength and failure mode of laminates. The results indicate that wrinkle defects reduce the flexural strength of the laminate by about 12% to 15%, and the flexural strength is positively correlated with the wrinkle smoothness S . As the wrinkles increase, the failure mode of the laminate gradually changes from local collapse under the punch to instantaneous shear failure in the wrinkle area, and the degree of warping and delamination increases. Therefore, avoiding wrinkle defects can effectively maintain flexural strength and reduce the extent of warping and delamination.