Laminated Plate and Shell Elements for Finite Element Analysis of Advanced Fiber Reinforced Composite Structures

Special plate and curved shell elements have been developed for the finite element analysis of fiber reinforced laminated composite structures. The formulation is based on a modified Hu-Washizu variational principle. The independent quantities subject to variation are displacements and the transverse components of stresses. The continuity of displacements, strains and stresses is exactly satisfied along interlayer surfaces. The individual cross-sectional rotations and thickness changes of each layer are allowed for the accurate evaluation of transverse stresses, including interlaminar normal stress which may produce catastrophic delamination failures. The present elements, which have eight nodes regardless of the total number of layers, can be used in conjunction with standard isoparametric shell elements and can lead to realistic solutions of practical design problems dealing with notches, holes and other out-of-plane loads in laminated composite structures.