Higher-Order Multifield Formulations for Shell Structures Made of Advanced Anisotropic Materials

In this contribution, an efficient formulation based on higher-order theories is presented for the multifield analysis of doubly-curved laminated anisotropic shell structures. Starting from the geometry description of the shell with curvilinear principal coordinates, a generalized model is derived that fully accounts for the coupling between mechanical elasticity, electricity, magnetism, thermal conduction, and moisture diffusion within the solid. The multifield governing equations are obtained from the Master Balance principle under thermodynamic equilibrium conditions. A semi-analytical solution is derived using the Navier method, considering fixed geometries, lamination schemes, and boundary conditions. The effective response of the shell is then reconstructed from the higher-order solution through an efficient recovery procedure based on the multifield balance equations, employing the Generalized Differential Quadrature (GDQ) or Generalized Integral Quadrature (GIQ) numerical methods. A validation investigation is performed against 3D FEM simulations to demonstrate the accuracy and the computational efficiency of the proposed solution. Furthermore, the effect of multifield coupling within the structure is explored by means of a large parametric investigation. The model can be effectively adopted in novel engineering applications, as it enables the study of additional multifield coupling effects, usually neglected in standard commercial codes, in a simple but accurate manner.