2022 年 48 巻 4 号 p. 123-133
Automated fiber placement can manufacture composite laminates at a low cost and in a short time; however, gaps and overlaps of plies are introduced due to the lack of positional accuracy of the robot arm. To clarify the effects of these processing defects, we observed the damage progression in carbon fiber reinforced plastic laminates with a manually introduced gap or overlap. Specimens were prepared under different forming conditions depending on the number of processing defects and the presence or absence of a cowl plate. In the case of formation without a cowl plate, specimens with a gap exhibited ply waviness in the through-thickness direction, the resin-rich region, and thickness reduction at the gap position. Thickness increase and ply waviness were observed at the overlap position. Sequential edge face observation experiments showed that specimens without cowl plates exhibited early delamination near the gap/overlap defect. The strain distributions at the defect location were measured using the digital image correlation method. Results showed that the thickness change at the defect location caused a shift in the neutral plane position, resulting in point-symmetric shear strain. Therefore, the early delamination was caused by the bending moment near the defect location.