Calculation of natural frequencies of beam structures including concentrated mass effects by the dynamic stiffness matrix method

In this paper, the dynamic stiffness matrix method for a 2-node and 6-DOF (Degree Of Freedom) per node beam element is presented along with a numerical method to include the effect of concentrated masses. We treat as examples the case of free vibrations of beam structures with and without the concentrated masses effect. By means of a parametric study, we assess the quantitative effect of concentrated masses to the natural frequencies of the structure.