Cutoff wave numbers for energy-orthogonal eight-node quadrilateral plane-strain elements

This paper studies the propagation of plane harmonic waves in plane-strain solids discretized by the standard eight-node quadrilateral finite element. This element is formulated in energy-orthogonal form. It means that the stiffness matrix is split into basic and higher order components which are obtained from the mean and deviatoric strain fields, respectively. The major subject is to obtain reference values for the wave number that can be used as optimum cutoff wave number to properly capture a wave field. The procedure is based on the properties of the higher order elastic energy.