Composite component incremental consolidation for fiber waviness inhibition and its effect on damage progression of curved beams

Abstract

Severe fiber waviness defect often occurs during the consolidation process of fiber reinforced polymer composite component, which arises from that multiple interactional plies start to slide simultaneously and out‐of‐control under sufficient pressure. In this study, based on the significant in‐plane tension gradient along thickness of viscoelastic composite, a concept of incremental consolidation was proposed to actively inhibit fiber waviness in prepreg‐based composite component. Via applying a series of tiny step pressures continuously, plies were triggered to slide and consolidate layer by layer from top to bottom with a just‐right in‐plane tension and concurrent stresses relaxation. Incremental consolidation avoided the complex interaction among plies and allowed in‐plane tension to be significantly reduced by 165 times compared with autoclave processing with a constant pressure. The fiber waviness defects in a typical wing spar were successfully inhibited by the proposed method. The failure load of the component increased by 1.5 times and curved beam strength increased by 1.1 times while elastic displacement increased by 75%. The inhibition method was highly effective, easy to implement and affordable, which showed considerable promise to improve the manufacturability of the primary structural composite components.

The effect of adhesively bonded external hybrid patches on the residual strength of repaired glass/epoxy‐curved laminates

“…The load increases with displacement in the linear elastic region until a sharp decrease at the delamination point at 4.67 mm displacement with a peak force of 769 N 42 . This drop in load (A 2 ) is related to the onset and progression of delamination, as seen in Figure 5B at 1/2 thickness from the inner radius 49 . The second load drop (A 3 ) at 4.84 mm with a peak force of 475 N indicated crack propagation along the crack path, and the second delamination was found at three‐fourth thickness from the inner radius.…”

The influence of thickness and recycled milled glass fiber fillers on the delamination resistance of polymer composite angle brackets

“…6 The photographic images of the propagation of delamination related to the respective load drops are shown in Figure 2B-D. 31 Further, the three drops of load in 32 layers specimen shows the propagation of delamination on the mid-section of the curved specimens. 32 A single load drop occurred at a displacement of 10.33 mm with a peak force of 1050 N for the 16 layers specimen. Further, the 24 layers specimen shows load drops at the displacement of 6.9 and 11 mm with peak force of 1330 and 667 N, respectively.…”