A flat triangular shell element with improved membrane interpolation

An 18 degrees-of-freedom flat triangular shell element is formulated using the DKT bending element and a new membrane stress formulation. The membrane stress formulation is based on a degenerate linear strain triangle utilizing in-plane rotations at each node. This new formulation is very simple and satisfies the plane stress patch test. Based on the numerical results from a rigorous set of test problems, the new formulation is shown to be an improvement over earlier attempts to improve the membrane stress in the shell element.