A mixed-enhanced finite-element for the analysis of laminated composite plates

Abstract

SUMMARY This paper presents a new 4-node nite-element for the analysis of laminated composite plates. The element is based on a rst-order shear deformation theory and is obtained through a mixed-enhanced approach. In fact, the adopted variational formulation includes as variables the transverse shear as well as enhanced incompatible modes introduced to improve the in-plane deformation. The problem is then discretized using bubble functions for the rotational degrees of freedom and functions linking the transverse displacement to the rotations. The proposed element is locking free, it does not have zero energy modes and provides accurate in-plane=out-ofplane deformations. Furthermore, a procedure for the computation of the through-the-thickness shear stresses is discussed, together with an iterative algorithm for the evaluation of the shear correction factors. Several applications are investigated to assess the features and the performances of the proposed element. Results are compared with analytical solutions and with other nite-element solutions. Copyright ? 1999 John Wiley & Sons, Ltd.