102—THEORETICAL CONSIDERATIONS OF BENDING AND CREASING IN A FABRIC

A mechanistic analysis of fabric flexure is outlined, relating fabric behaviour to fibre properties through the geometry of the structure, particularly as it is affected by fibre interactions. The influence of two factors is discussed : first, the degree of fibre association or clustering which exists within the yarn; secondly, the effect of the yarn intersections within the fabric in producing a cyclic fluctuation of rigidity along the length of the yarn. Equations are derived which show the influence of these factors on the flexural rigidity of the fabric, and on the average maximum strain to which the fibres are subjected in any bent configuration. The practical implications of this concept are discussed in terms of fabric stiffness and wrinkle recovery.