In order to investigate the vibration characteristics and dynamic responses of
complicated shell structures with geometrical and material nonlinearities, it is essential
to formulate shell finite elements that are easy to use, accurate, effective, and applicable
to thin as well as moderately thick shells. This chapter presents the development of the
mixed formulation or hybrid strain based three-node flat triangular shell elements, with
a particular emphasis on the linear analysis of thin to moderately thick shells. Section
2.1 gives a brief introduction and an outline of the features of the shell elements.
Section 2.2 deals with the derivation of consistent stiffness and mass matrices of a
particular element. In Section 2.3, results and discussions pertaining to rigid-body
modes, patch test, and mesh topology are presented. Concluding remarks are given in
Section 2.4.
Keywords: Mixed formulation, three-nodes, triangular, shell finite elements,
vibration analysis.
