MITC finite elements for laminated composite plates

Within the framework of the first-order shear deformation theory, 4- and 9- node elements for the analysis of laminated composite plates are derived fr om the MITC family developed by Bathe and coworkers. To this end the bases of the MITC formulation are illustrated and suitably extended to incorporat e the laminate theory. The proposed elements are locking-free, they do not have zero-energy modes and provide accurate in-plane deformations. Two cons ecutive regularizations of the extensional and flexural strain fields and t he correction of the resulting out-of-plane stress profiles necessary to en force exact fulfillment of the boundary conditions are shown to yield very satisfactory results in terms of transverse and normal stresses. The featur es of the proposed elements are assessed through several numerical examples , either for regular and highly distorted meshes. Comparisons with analytic al solutions are also shown. Copyright (C) 2001 John Wiley & Sons, Ltd.