Stress analysis of junction of plate and shell built-up structures via special finite shell element

A finite element formulation using the penalty function method to analyze exactly the junction of plate and shell built-up structures is suggested for an isoparametric shell element. The connectivity condition at the junction is added to the potential energy functional by the penalty parameter and the interpolating function of displacements. This formulation yields an integral-type stiffness matrix of the special junction elements, which can directly evaluate the surface tractions at the junction. The suggested technique is applied to the stress analyses of isotropic and laminated plates with several types of stiffeners, and the validity of the technique is discussed.