Failure criterion for PTFE coated fabric

The PTFE coated fabric is taken in the research object. Groups of off-axial tensile tests are carried out, including 0°, 15°, 30°, 45°, 60°, 75° and 90°. The failure mechanisms and the corresponding static results are discussed. When using the Tsai-Hill strength criterion to predict the failure strength of PTFE coated fabrics, the prediction results are in good agreement with the test data in most of the specimens, except that in 15° and 75° directions. The disagreements could be attributed to the unbalanced structure of warp and fill due primarily to the crimp interchange in weaving and coating processes. Finally, a modified criterion is proposed.