A co-rotational 8-node degenerated thin-walled element with assumed natural strain and enhanced assumed strain
In recent years, solid-shell elements with the absence of the rotational degrees of freedom have considerable attentions in analyzing thin structures. In this paper, the non-linear formulation of a co-rotational 8-node degenerated thin-walled element with no rotational degrees of freedom is presented to demonstrate the solutions of linear and geometrically non-linear analysis for plate and shell structures. The assumed natural strain (ANS) and enhanced assumed strain (EAS) are used to overcome various locking problems, while the co-rotational formulation is employed to remove rigid body rotations for solving geometrically non-linear problems. In addition, the element formulation here uses plane stress condition in order to fit to thin-walled and shell applications, and the global, local and natural coordinate systems are employed to conveniently model the thin-walled geometry. Several numerical examples are presented to demonstrate the performance of the present element and the results are in good agreement with the references.
assumed natural strains enhanced assumed strains 8-node solid element co-rotational method geometrical nonlinearity