Spiry-layup model of Rutelidae cuticle

In this study, the microstructures of Rutelidae cuticle, a natural biocomposite, were observed with scanning electronic microscope (SEM). It was found that the insect cuticle has a laminated microstructure consisting of chitin fiber and protein matrix. There are particular spiry layups in the cuticle. The maximal pull-out force of the spiry layup is analyzed and compared with that of conventional 0°-layup based on their representative models. The result shows that the pull-out force of the spiry layup is markedly larger than that of the conventional 0°-layup. The corresponding experiment on the maximal pull-out forces of both spiry layup and the 0°-layup is conducted, and it shows that the maximal pull-out force of the spiry layup is markedly larger than that of the 0°-layup, which verifies and demonstrates the validity of the presented model.