An eight-node hybrid-stress solid-shell element for geometric non-linear analysis of elastic shells

摘要

This paper presents eight-node solid-shell elements for geometric non-linear analysis of elastic shells. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. A selectively reduced integrated element is formulated with its membrane and bending shear strain components taken to be constant and equal to the ones evaluated at the element centroid. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger-Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid element, a hybrid-stress solid-shell element is formulated. Commonly employed geometric non-linear homogeneous and laminated shell problems are attempted and our results are close to those of other state-of-the-art elements. Moreover, the hybrid-stress element converges more readily than the selectively reduced integrated element in all benchmark problems.