Effect of warp yarn paths on bending properties of 3D woven composites

Three types of 3D woven composites (3DWC) with different warp paths were designed. Using a combination of experimental research, finite element analysis and SEM morphology analysis, the bending properties, damage mechanism and fracture morphology of 3DWC were studied. The results show that the warp paths have a significant effect on the bending properties of 3DWC. Compared to the stuffer plain woven composites (SPWC), with the increase of the warp yarns float length, the stuffer twill and stuffer stain woven composites (STWC and SSWC) bending strength increase by 54.64% and 127.61%, and the modulus increase by 44.11% and 47.11%, respectively. The failure modes of the SPWC are the fracture of the stuffer and the warp yarns, while the fracture modes of the STWC and SSWC are mainly yarns fracture and interface debonding. The stuffer yarns play the main role under the process of bending load, while the difference of warp yarn paths leads to the change of stress transfer, crack propagation, bending property and failure mode of three 3DWC.