Effect of the fabric dimension on limits of the drape coefficient

The effects of fabric dimension on drape deformation are analyzed using a model of a circular segment cantilever for infinite shear stiffness (upper limit) and the deflection of strip cantilevers in radial directions for zero shear stiffness (lower limit). The drape shapes are determined by nondimensional parameters K and K′ in addition to the parameters m and m′, which are given by the ratio of the fabric radius and segment cantilever length, respectively. K and K′ are given by the segment cantilever length for the upper limit and by the differences between the radii of the fabric and support disk for the lower limit, with weights, and bending rigidity. The drape coefficient (DC) limits of fabrics are theoretically obtained using the model in three cases according to the relationship of m and m′. Even for different fabrics, the drape shapes are similar for the same m and K, or m′ and K′, in each case. The effects of dimension on fabric drape are therefore clarified theoretically. The obtained limits are experimentally verified for eight woven fabrics and one sheet. It is found that the DCs of samples are between the two theoretical curves of limits, although there are variations even for the same K or K′. The variations might be due to depressions between adjacent nodes or the presence of double-curvature deformation due to lower shear stiffness. The effects of dimensions in the drape test considering bending rigidity for infinite and zero shear stiffness are thus clarified theoretically and experimentally.