WrapToR composite truss structures: Improved process and structural efficiency

Wrapped Tow Reinforced (WrapToR) trusses are ultra-efficient composite structural members that are produced using a novel winding process. In this study, a novel technique is employed during the manufacturing process to improve structural efficiency. By twisting the fibre tow bundle during winding, more consistent shear members were produced that displayed improved buckling resistance. Results from a three-point bend test showed this technique to increase truss failure load by 51% for a particular truss size that is prone to shear web buckling. Comparison of experimental deflections to a previously developed structural analysis tool highlight the importance of capturing deflections due to shear loading. Finally, the truss configuration is experimentally compared to commercially available carbon fibre tubes. When compared to an 8 mm pultruded tube, the truss configuration displayed 9% lower mass, over double the load carrying capability and 6.7 times the flexural rigidity.