In-plane dynamic stiffness matrix for a free orthotropic plate

•We present a procedure for calculating the in-plane dynamic stiffness matrix of free orthotropic plates.•Free boundary conditions are required for plate assemblies.•Harmonic analysis for three load cases is presented.•The numerical validation is achieved thanks to comparisons with FE results.

The aim of this paper is to describe a procedure for computing the dynamic stiffness matrix relative to the in-plane effect for an orthotropic rectangular plate. The dynamic stiffness matrix is calculated for free edge boundary conditions. The formulation is based on strong solutions for the equations of motion for an orthotropic plate obtained with the Levy series and a Gorman decomposition of the free boundary conditions. The results obtained for the in-plane harmonic response are validated by the Finite Element Method.