THE INFLUENCE OF ADDED-MASS TO A CHANGE OF EIGENFREQUENCIES

Any change in a structure leads to a change in the dynamic characteristics of the structure, so monitoring changes of the dynamic characteristics and a judgement of their origins is very important. The causes of such disturbing effects (geometrical disorders as, for example, cracks) in a structure have to be detected immediately for reasons of safety. Inverse dynamic identification is a field of dynamics of structures that investigates the reasons of known effects. In order to achieve efficient realisation of inverse identification, we must understand the methods of dynamic identification. This paper deals with the effects of added mass to a change in the eigenfreguencies of a free-supported beam in three ways: with an analytical and two numerical procedures. A comparison of obtained results with data on the real structure is also presented.