Abstract: According to the characteristics of the flexible mechanism systems, an efficient method is presented for finite element modeling of three layer frame element containing a viscoelastic layer. The shape functions for the two node and eight degrees of freedom frame element are presented. The equations of motion of the damped flexible mechanism are derived. Modal damping ratios are Predicated. From undamped normal mode by means of the modal strain energy method. Comparisons between the results obtained by this paper and the results obtained by exact solution of the governing equations demonstrate that the presented method is correct, efficient and reliable, It is believed that the method had the potential for optimal design for damped flexible mechanism systems.

Key words: Modal loss factor, Damping, Flexible mechanism, Vibration control