A comparative analysis of a modified picture frame test for characterization of woven fabrics

An experimental, finite-element analysis framework is utilized to estimate the deformation state in a modified version of the picture frame test. During the analysis, the effect of fiber misalignment and the deformation heterogeneity in the tested fabric, a 2 × 2 PP/E-Glass twill, is accounted for and a force prediction model is presented. Using an equivalent stress-strain normalization scheme, the comparison of the modified test with the conventional (original) picture frame and biasextension tests is also made, and results reveal similarities and differences that should receive attention in the identification of constitutive models of woven fabrics using these basic tests. Ideally, the trellising behavior should not change from one test to another but results show that in the presence of fiber misalignment, the modified picture frame test yields a behavior closer to that of the bias-extension test, while the general form of the test's repeatability, measured by a signal-to-noise metric, remains similar to the original picture frame test. POLYM. COMPOS., 31:561-568, 2010.