Abstract
The effects of some factors on the bending rigidity of a seam, such as the kind and the direction of fabric, stitch size and the length of seam allowance are investigated. Supposing that the rigidity of a seam part is different from that of the other part excluding a seam, the increment of rigidity by a seam is defined as the effect of a seam on rigidity, the following equation is devised :
(EIs) X= (EI0) + (EI2) X
where (EIs) and (EI2) are the bending rigidity per unit width of a sewed sample as a whole and that of the sample part excluding a seam, (EI0) is the effect of a seam on rigidity and (X) is the width of a sample.
By plotting (EIs) X to X, the applicability of the equation is confirmed and values of EI0 and EI2 are obtained.
On the other hand, (EI0) is calculated from Young's modulus (E) of the sample fabric and the moment of inertia of area of sectional shape of a seam part (I0). Two values of EI0 thus obtained are compared with each other and the effects of some factors on EI0 and EI2 are discussed.
