Experimental study and simulation of non-crimp 3D orthogonal composite shafts during torsional load

Non-crimp 3D orthogonal fabrics are high-tech textiles with three sets of orthogonal yarns. 3D composites reinforced by this fabric have a high performance and wide usages due to their structure. This study attempted to investigate the torsional behavior of Glass/epoxy composite rods reinforced by 3D fabrics experimentally and numerically. Accordingly, three different 3D weaves, including low-density and high-density non-crimp 3D orthogonal, and braid-pultruded fabrics were tested by a torsion tester machine. The results showed that non-crimp 3D orthogonal composites, especially those with a higher density, had better torsional properties than the others, due to the square cross-section and perpendicular fiber involvement in all directions. Optimal torsional properties were obtained for the high-density non-crimp 3D orthogonal composite with the lower void content. Also, a python code was developed to simulate the torsional behavior of the rod composite in macro-scale based on the geometry of the unit cell and the mechanical constants obtained from the meso-scale.