Experimental characterization of steel fibre knitted fabrics deformability

Extremely fine steel fibres (12 μm diameter) are spun into yarns and then knitted into fabric, which is used, among other applications, as a mould cover in forming of automotive glass. High requirements of the glass quality (absence of dioptric distortions) ask for a perfect evenness of the mould cover surface, which depends on the local distortions of the fabric, created during tensioning of the fabric over the mould. These distortions can be predicted using nonlinear finite element draping simulation, providing that the material laws describing the fabric resistance to deformation are known. This article describes an experimental procedure for derivation of such laws using biaxial tension, shear, and compression tests. Test results for a typical steel fibre knitted fabric are presented together with an example of the draping simulation.