Zmienność parametrów modalnych w zależności od charakteru zniszczenia elementów belkowych

The paper discusses methods of diagnosing the technical condition of reinforced concrete beams, based on the change in dynamic characteristics. The objects of research were reinforced concrete (RC) beams. Testing of RC beams included both static and dynamic tests. A series of step loaded static tests was aimed to produce successive damage to the beams. After each load step (at the moment of displacement and strain stabilization), dynamic testing followed. On the basis of the obtained results from different beams (different distances between supports), an effort was made to correlate the data concerning the damage of the tested beams with the changes of the modal parameters.