Modifications of cascade structures in computer aided design of mechanical continuous vibration bar systems represented by graphs and structural numbers

The dynamical flexibility of continuous free systems with definite frequency spectrum and with cascade structure has the alternating: pole, zero, pole, zero, etc. The frequency with the zero value is always a pole. On the other hand, in the case of systems with cascade structure but fixed at one side, the dynamical flexibility has the alternating: zero, pole, zero, pole, etc. respectively. The frequency with the zero value is always a zero. In this paper the method distribution of characteristics into partial fraction and recurrent cascade method represented by graphs were applied in order to structural modification of the vibrating mechanical system with cascade structure.