Implementation of a flat facet shell finite element for applications in structural dynamics

The bending and membrane consistent mass matrices are derived for a triangular flat facet finite element for the analysis of general thin shells. This implementation of the element is for applications in structural dynamics; it has the novel feature of including the effect of the rotatory inertia associated with the drilling rotation degree of freedom which could not be property accounted for in earlier developments. To test the validity of the formulation, numerical results for natural frequencies are compared to known solutions of example problems and to a simple experiment on a folded plate. A comparison of results is also obtained using traditional lumped mass matrices.