vibration modelling for systems with complex structure

This paper presents vibration model and vibration analysis of a mechanical system with two components. Each mechanical system has a resonant frequency and if the external force which acts on the system has the same frequency, the vibration caused by the force leads to destruction. Mechanical systems have many components which are fixed together in different ways and react in different manner to an external force. The question is how reacts a system composed of two different masses to a sinusoidal base vibration. The article presents a possible model of a frame. The frame is modeled with two concentrated masses. The moving equations are developed for this model, than the movements of the masses and of the model are studied in different cases, different vibration frequencies, different stiffness and masses. For the study Matlab simulation was used. The resonant case was also studied. The simulation result shows that the stability of the frame depends on the number of the columns, the frequency of the vibration and on the masses.