Enhanced Shell Elements For The Numerical Simulation Of Industrial Processes L. Neamtu (*) , F. Flores (**) , R. Weyler (*) , G. Duffett (*) (*) QUANTECH ATZ, Barcelona, Spain (**) National University of Cordoba, Cordoba, Argentina Abstract. This paper briefly describes a rotation-free three-node triangular shell elements enhanced formulation and some industrial processes applications where the robustness and accuracy of the element behaviour have been validated. The enhanced formulation is an extension of the rotation free lamina elements (BST, EBST), used for the analysis of smooth surfaces, to the general study of complex branched surfaces behaviour (profiles). INTRODUCTION The concept of using rotation-free finite elements for shells is not completely new and the basic ingredients of the method are a mixed Hu-Washizu formulation, a standard discretization into three node triangles, a linear finite element interpolation of the displacement field within each triangle and a finite volume type approach for computing constant curvature and bending moment fields within appropriate non-overlapping control domains. The so- called “cell-centered” and “cell-vertex” triangular domains yield different families of rotation-free plate and shell triangles. The termed BST (for Basic Shell Triangle) shell element can be derived from the cell- centered formulation. Here the “control domain” is an individual triangle. The constant curvatures field within a triangle is computed in terms of the displacements of the six nodes belonging to the four elements patch formed by the chosen triangle and the three adjacent triangles. Details can be found in [1]. In this paper an enhancement of the BST element is briefly presented in order to deal with branched shells behavior. BASIC CONCEPTS Let us consider a patch of four three node triangles (FIGURE 1) where the nodes 1, 2 and 3 in the main central triangle (M) are marked with circles while the external nodes in the patch (4,5 and 6) are marked with squares. The central triangles mid side points are marked with smaller squares. FIGURE 1. Patch of three node triangular element including the central triangle (M) and three adjacent triangles (1, 2 and 3) FIGURE 2. Patch of elements in the isoparametric space 762 CP778 Volume A, Numisheet 2005, edited by L. M. Smith, F. Pourboghrat, J.-W. Yoon, and T. B. Stoughton © 2005 American Institute of Physics 0-7354-0265-5/05/$22.50