Research On Inter-layer Performance Of2.5D Woven Composites

As an important component of3D woven composites,2.5D woven composites has been a newreinforced composites in recent years. The main feature that the yearn keeps a certain angle with thethickness direction of fabric enables the bonding of fiber layer by layer. Thus, the bonding strengthbetween the layers of reinforced fabric is considerably improved and the composite obtains anexcellent anti-impact ability. The property of low cost, high efficiency and good comprehensiveperformance make the2.5D composites widely used in the aviation, aerospace and transportationfields. Thus it is of great significance to further research the property of2.5D woven composites.The thesis focuses a comprehensive research on the inter-layer performance of2.5D wovencomposites from the theoretical model, FEM analysis and experiment validation. Some usefulconclusions are made.The runway section assumption is made to build a mesoscopic geometrical model of2.5D wovencomposites. The representative volume element is chosen to build the FEM model of unit cell.The periodic boundary condition is introduced. Based on the unit cell model and dual notchmodel, the inter-layer shear property of2.5D woven composites is researched and the stress-straincurve under the loading is simulated.The moulding process of2.5D woven composites is researched. All the test specimen aremanufactured with RTM moulding method. The experiment of inter-layer shear along warp and fillingof2.5D woven composites is done through both the dual notch shear method and the short beam shearmethod. The experiment result is compared and analyzed with the FEM result, which validates theeffectiveness of the FEM model and the experiment method.