Geometrically nonlinear analysis of functionally graded composite shells using MITC4 and MITC9 elements: Fid-Bau Portal

Geometrically nonlinear analysis of functionally graded composite shells using MITC4 and MITC9 elements

Trinh, Minh-Chien / Jun, Hyungmin

Abstract In this paper, the geometrically nonlinear behaviors of functionally graded composite shells under large displacements and large rotations are analyzed. Instead of constructing conventional layer-wised models, equivalent single-layer composite shell elements based on general displacement fields are developed to model the inhomogeneity of composite materials. The mixed interpolation of tensorial components technique is used to eliminate membrane locking and shear locking phenomena. The assumed covariant strain fields are initially constructed before being used to evaluate the second Piola–Kirchhoff stress and construct stiffness matrices in local Cartesian coordinates. The standard full Newton–Raphson method is utilized to solve a system of nonlinear equations. Geometrically nonlinear analyses are performed on different thin-walled composite structures including thin cantilever beams, slit annular plates, pinched cylindrical shells, and hemispherical shells. Obtained results demonstrate good convergence characteristics and modeling capability of the developed quadrilateral composite shell elements in analyzing thin-walled composite structures.

Highlights • Four-node and nine-node composite shell finite elements are presented. • Geometrically nonlinear behaviors of thin-walled composite structures are examined. • MITC technique is used to eliminate membrane-locking and shear-locking phenomena. • Analyses on composite beam, plate, cylindrical and hemispherical shells are performed. • Developed finite elements show good modeling capability for geometrically nonlinear analysis of thin-walled composites.