# Axisymmetric elements allowing nonlinear bending

 Abaqus/Standard provides axisymmetric solid elements with nonlinear, asymmetric deformation. The following topics are discussed:
 Related Topics In Other Guides Axisymmetric solid elements with nonlinear, asymmetric deformation

ProductsAbaqus/Standard

The element library contains solid elements whose geometry is initially axisymmetric and that allow for nonlinear analysis in which bending can occur about the plane $θ=π/2$ in the (r, z, $θ$) cylindrical coordinate system of the model. The geometric model is defined in the rz plane only. The displacements are the usual isoparametric interpolations with respect to r and z, augmented by Fourier expansions with respect to $θ$. Since the elements are written for bending about the plane $θ=π/2$ only, they cannot be used to model torsion of the structure about the original axis of symmetry. Because the elements are intended for nonlinear applications, the orthogonality properties associated with Fourier modes cannot be used to reduce the problem to a series of smaller, uncoupled, cases, since the stiffness before projection onto the Fourier modes is not necessarily constant. For this reason these elements are significantly more expensive to use than the corresponding axisymmetric elements intended for axisymmetric deformations.