Indirect Measurement of the Moment-Curvature Relationship for Fabrics

An indirect method of experimentally measuring the moment-curvature relationship for fabrics is developed in this study. The new test method involves recording the deformed coordinates of a fabric sample as it is cantilevered under its own weight from a fixed support. By applying least squares polynomial regression and numerical differentiation techniques, the coordinate data along with the values of fabric weight per unit area are used to construct the moment-curvature relationship of the fabric. This method and its associated computer algorithm have been validated by numerical simulations and experimental observations. The nonlinear moment-curvature rela tionship was used to approximate the nonlinear bending stiffness in fabrics. The ad vantage of this method is that the fabric nonlinear bending behavior, which is inherent in most fabrics, can be well represented; this property may not always be obtained from the traditional cantilever beam test.