Experimental determination of shear properties, buckling resistance and diagonal tension field of polyurethane coated nylon fabric

Experimental methods have been employed to acquire shear properties, examine buckling, and postbuckling response, and to characterize out-of-plane deformations of thin orthotropic polyurethane-coated nylon fabric designated for use in the finite element analysis of an inflatable structure. A custom-designed bi-axial pre-tension frame, a picture-fame rig, and a photogrammetry system were used to apply pre-tension, collect the angular and linear displacements, and to capture the buckling and wrinkle-forming mechanisms in the coupons during the shear test. The series of monotonic picture-frame tests provided with an average critical shear stress of 0.16 MPa that was required to buckle the coupons for a small range of the pre-tension force. While an average pre-buckling shear modulus (28.5 MPa) was obtained, only 2.25% of a relative difference between the average post-buckling apparent shear modulus (13.07 MPa) and the average shear modulus obtained from the 45° bias-extension test for the same material (13.3...