28—A THEORETICAL ANALYSIS OF THE TENSILE PROPERTIES OF PLAIN-KNITTED FABRICS. PART II: THE INITIAL LOAD-EXTENSION BEHAVIOUR FOR FABRIC EXTENSION PARALLEL TO THE WALES

A theoretical analysis is made of the load-extension behaviour of plain-knitted fabrics for the case in which extension takes place parallel to the wales. The analysis is performed by examining the deformation of the three-dimensional loop shape, this shape having been described in a previous paper. The calculated values of the initial tensile modulus are compared with those obtained experimentally from a series of wool fabrics. The theoretical values are lower (though of the correct order of magnitude) than the experimental values; this effect is explained by frictional resistance to yarn slippage.