Robust flat‐facet triangular shell finite element

Abstract

AbstractA flat facet finite element with three nodes and six degrees of freedom per node for linear static and dynamic analysis of thick and thin shells is presented. The membrane response is modeled with constant strain triangles. The bending response treats the transverse shear with an improved version of the discrete‐shear‐gap technique. The main novelty of the present approach is the robust treatment of the drilling rotations: the element internally responds to five degrees of freedom per node, but externally it naturally possesses six degrees of freedom per node. The drilling degree of freedom is decoupled from the bending and twisting, and the undesirable user‐selectable arbitrary stabilization is avoided. The element is shown to be robust for extremely thin shells, and passes tests such as the Raasch hook problem. Performance is illustrated with static and dynamic examples including branched and folded shells.