For certain highly curved shells, such as bellows, the formulation of a curved-shell finite element with curvilinear displacement components may fail to properly model some rigid body modes, even with either the explicit inclusion of rigid-body terms or the use of high-order displacement functions. It is suggested in this paper that the rigid-body modes can be properly included if the Cartesian displacement components are used. A 48-degree-of-freedom (DOF) curved thin-shell element is formulated, and both the curvilinear and the Cartesian forms are used for this investigation. Examples of the nonlinear analyses of a bellows shell and a spherical cap are given to demonstrate the advantage of using the Cartesian formulation. Curved elements may also suffer from membrane locking, which is caused by the inability of an element to bend without stretching. Numerical data are presented to show that the present element does not membrane lock. Some nonlinear examples are also presented to further demonstrate the versatility of this element.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering