MODIFIED 3-DIMENSIONAL FINITE-ELEMENT FOR GENERAL AND COMPOSITE SHELLS

A new shear deformable finite element formulation has been developed for the linear static analysis of general, homogeneous and laminated composite shells. It is based on the reduction of a three-dimensional element to a two-dimensional element by the use of substitute degrees of freedom. The proposed formulation incorporates a realistic cubic variation of the warping of the cross-section and also accounts for the transverse normal strain energy in the derivation of the total potential energy of the structure. Analytical integration along the shell thickness direction is carried out by taking quadratic variation of the determinant of the Jacobian matrix. The elements considered are a seven-node triangle and eight- and nine-node quadrilaterals. Reduced Gauss integration is used to evaluate the various element property matrices. A number of problems from thin isotropic shells to thick laminated composite shells have been solved to check the accuracy of the proposed formulation and to study the effect of transverse shear deformation on the response of thick sandwich and composite shells.