Experimental investigation of in-plane shear performance for F-12 aramid fabric

The in-plane shear performance for F-12 aramid fabric was investigated. The picture frame test and bias-tensile test were conducted. A new picture clamp was designed. The deformation field of fabric during the test was measured by digital image correlation (DIC) technique. The shear force vs. shear angle curves and the locked angle were obtained. Normalized method was used to compare the two experimental results. Then, numerical method was used to compute the shear characters. A non-orthogonal anisotropic truss-shell model was established to simulate the bias-tensile test. A user defined material subroutine was developed to calculate the direction of the yarns and stress updated. To verify the validity of the model, the simulated results were compared with experimental results. The test results show that the shear performance of the fabric is non-linear. The clamping arm can affect the test results. The force of no silts sample is larger than that of infinite slits sample. The locked angles of these two samples are equal. After normalized, the force of picture frame test is larger than that of bias-tensile test, while the locked angle is smaller. The FEM results agree well with experimental results.