Abstract:

Inspired by the structural adaptations of natural biological organisms, helicoidal composite architectures have shown significant potential for enhancing toughness, strength, and weight efficiency in engineering applications. However, temperature and moisture’s adverse effects pose challenges during service, potentially compromising their overall performance. This study meticulously analyzes the buckling and vibration behavior of carbon nanotube (CNT)-reinforced bioinspired helicoidal composite plates under different hygrothermal conditions. A novel aspect of this study lies in the proposition of a multiscale analysis combining the analytical and numerical techniques to assess the effects of temperature, moisture, weight fraction of CNTs, layup configurations of bioinspired designs, aspect ratios, loading and boundary conditions, and geometric shapes of bioinspired helicoidal composite structures on their vibration and buckling characteristics. In this context, the stiffness properties are computed with the Halpin-Tsai model, incorporating the size-dependent features of CNTs along with their waviness and agglomeration. In addition, the Chamis micro-mechanical equations are used to determine the elastic properties of individual layers constituting bioinspired composites, considering the effects of temperature and moisture. The kinematics of the laminated bioinspired structures are captured with the third-order shear deformation theory (TSDT) within the isogeometric framework employing the non-uniform rational B-splines (NURBSs) as the basis functions. The isogeometric framework ensures higher-order inter-element continuity and provides an exact geometric representation, offering various advantages over the traditional finite element method. The developed framework is validated against the existing literature, and thereafter several numerical examples are presented, providing valuable insights for the design and optimization of bioinspired composite structures, with potential benefits for various engineering fields, including marine and aerospace sectors.

Key words: bioinspired, hygrothermal, carbon nanotube (CNT)-reinforced, higher-order shear deformation theory (HSDT), isogeometric analysis (IGA), buckling, vibration