On the nonlinear buckling analysis of composite shells and the associated numerical difficulties


Akkas N., Toroslu R.

1st International Conference on Engineering Computational Technology/4th International Conference on Computational Structures Technology, Edinburgh, Saint Helena, 18 - 21 August 1998, pp.223-231 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Edinburgh
  • Country: Saint Helena
  • Page Numbers: pp.223-231
  • Middle East Technical University Affiliated: No

Abstract

The purpose of this work is to study nonlinear, snap-through buckling behavior of shallow shells which are made of isotropic and laminated composite materials under general static loading using numerical techniques. In addition to the finite difference computer programs which we developed for this special purpose, the general pur-pose computer program ANSYS has also been used. The special purpose programs that we have developed make use of the governing equations, which are in terms of the displacement components, of the isotropic and laminated composite shells. Effects of isotropic and laminated composite materials on the nonlinear behaviour of the shells ale investigated and the results obtained from the finite difference programs and from ANSYS have been compared for the two types of materials considered. Apparently because of the high order of the derivatives in the governing equations, numerical imperfection (inaccuracy) problems have arised in the solution. To eliminate these problems, the order of the derivatives has been lowered. In addition. various finite difference grid definitions have been applied around apex which turned out to be the most problematic region of the problem under consideration.