A two-node curved axisymmetric shell element based on coupled displacementfield

An efficient two-node curved axisymmetric shell element is proposed. The el ement with three degrees of freedom per node accounts for the transverse sh ear flexibility and rotary inertia. The strain components are defined in a curvilinear co-ordinate frame. The variation of normal displacement (w) alo ng the meridian is represented by a cubic polynomial. The relevant constitu tive relations and the differential equations of equilibrium in the meridio nal plane of the shell are used to derive the polynomial field for the tang ential displacement (u) and section rotation (theta). This results in inter dependent polynomials for the held variables w, u and theta, whose coeffici ents are coupled by generalized degrees of freedom and geometric and materi al properties of the element. These coupled polynomials lead to consistentl y vanishing coefficients for the membrane and transverse shear strain field s even in the limit of extreme thinness, without producing any spurious con straints. Thus the element is devoid of membrane and shear locking in thin limit of inextensible and shearless bending, respectively. Full Gaussian in tegration rules are employed for evaluating stiffness marix, consistent loa d vector and consistent mass matrix. Numerical results are presented for ax isymmetric deep/shallow shells having curved/straight meridional geometries for static and free vibration analyses. The accuracy and convergence chara cteristics of this CO element are superior to other elements of the same cl ass. The performance of the element demonstrates its applicability over a w ide range of axisymmetric shell configurations. Copyright (C) 1999 John Wil ey & Sons, Ltd.