Study on the resin flow and fiber compaction of tapered composite laminates during autoclave processing

During bleeding autoclave processing, resin flow occurs inside composite laminates because of the utilization of bleeder materials. For the tapered laminates, the masses of bleeder materials placed on thick, tapered, and thin regions should be optimized to obtain appropriate fiber content with uniform distribution. This article mainly focuses on the carbon fiber fabric/epoxy resin-tapered laminates processed under different bleeder schemes, and the effects of bleeder schemes on the resin flow and fiber compaction. The resin pressure variations were studied by means of an on-line monitoring method to analyze the resin flow. Moreover, the resin pressure gradients and resin flow directions at different situations were given. The results demonstrate that the on-line resin pressure measuring system can provide important information for the investigated resin flow and fiber compaction of composite parts with different thickness regions. In addition, the mass and saturation degree of the bleeder materials strongly influence the resin pressure distribution and the flow direction. Resin flow continues within the laminates after the saturation of the bleeder materials, and hence, significantly impacts on the distribution of the fiber content. These observations provide a significant guidance for designing the bleeder scheme and controlling the fiber compaction.