A mixed FSDT finite element for monoclinic laminated plates

A 4-node finite element for the analysis of laminated composite plates with monoclinic layers, as it occurs for example in piezoelectric applications, is developed. The element is built through the linked interpolation scheme proposed by Taylor and Auricchio [Int J Numer Meth Eng 1993;36:3057–66] and is a generalization of the element presented in [Auricchio F, Sacco E. A mixed-enhanced finite-element for the analysis of laminated composite plates. Int J Numer Meth Eng 1999;44:1481–1504]. Starting from a first-order shear deformation theory (FSDT), a mixed-enhanced variational formulation is considered. It includes as primary variables the resultant shear stresses as well as enhanced incompatible modes, which are introduced to improve in-plane deformations. Bubble functions for rotation degrees of freedom and functions linking transversal displacement to rotations are employed. The solvability of the variational formulation is proved whereas effectiveness and convergence of the proposed finite element are confirmed through several numerical applications. Finally, numerical results are compared with the corresponding analytical solutions as well as to other finite-element solutions.