A criterion to select dynamic modes for plates formulated within the framework of parametrized variational principles

This paper approaches the convergence question of the dynamic modes computed in Kirchhoff plates by the finite element method. It is concerned about energy-orthogonal plate elements formulated within the framework of parametrized variational principles. In these ones the stiffness matrix is split into basic and higher order components which are produced from the mean and deviatoric strain fields, respectively. The major subject of this paper is to decide which modes to keep for subsequent calculations such as transient response analysis. Truncation is done according to an higher order energy cancellation criterion that may be tested mode by mode.