A hybrid stress ANS solid-shell element and its generalization for smart structure modelling. Part I - solid-shell element formulation

In the recent years, solid-shell "nite element models which possess no rotational degrees of freedom and applicable to thin plate/shell analyses have attracted considerable attention. Development of these elements are not straightforward. Shear, membrane, trapezoidal, thickness and dilatational lockings must be envisioned. In this part of this paper, a novel eight-node solid-shell element is proposed. To resolve the shear and trapezoidal lockings, the assumed natural strain (ANS) method is resorted to. The hybrid-stress formulation is employed to rectify the thickness and dilatational locking. The element is computationally more e$cient than the conventional hybrid elements by adopting orthogonal-assumed stress modes and enforcing admissible sparsity in the #exibility matrix. Popular benchmark tests are exercised to illustrate the e$cacy of the elements. In Part II of the paper, the element will be generalized for smart structure modelling by including the piezoelectric e!ect.