Analysis of a Novel 3D Hybrid Woven/Knitted Fabric Structure: Part II: Mechanical Model to Predict Modulus and Extension

In Part I of this series, a geometric model was developed to predict loop length, yarn consumption, and thickness of a novel 3D hybrid woven/knitted fabric structure. In this part, a mechanical model is generated for estimating the Young's modulus and extension of the 3D hybrid woven/knitted fabric structure. Castigliano's theorem is used to derive the relations. The compression, extension, and bending energies of yarns are considered for the total strain-energy formula of the fabric. The mechanical model is verified for the fabric Young's modulus. There is reasonable agreement between theory and experiment considering the assumptions made and the complexity of the 3D fabric structure. The deviation is less with high performance multifilament fibers in the warp and bias yarns.