Modeling uniaxial tensile properties of multiaxial warp knitted fabrics

Multiaxial warp knitted (MWK) fabrics were formerly developed as substrates for flexible coated fabrics. They have an important role in industrial applications due to their outstanding mechanical properties. At the beginning of the 1990s, MWK fabrics entered the field of rigid structural composites to produce aerospace quality components, marine parts, and automotive frames. Although many papers have been published on the technology, structure, and properties of MWK fabrics as well as their composites, so far there is no model dealing with mechanical properties, which greatly restricts the designs and applications of these fabrics. In this paper, a uniaxial tensile model is built, and a formula for calculating the tensile modulus of the fabric in any direction is presented. In addition, the theoretical model is justified by the tests from the Instron 4466, which show good agreement between theoretical and experimental results.