Free vibrations of reinforced concrete and fiber-reinforced concrete airfield slabs

In the laboratory, samples of hollow and airfield slabs were made in two versions - concrete and steel-fiber concrete. The same structure were made in factory conditions, but in serial execution. A modal analysis of all fabricated structures was performed in the laboratory of the Department of Structural Mechanics of the Odessa State Academy of Civil Engineering and Architecture, followed by computer modeling and numerical analysis of all these structures by the finite element method in three software packages. A comparative analysis of all obtained theoretical, experimental and computer results showed the following: the frequency spectrum calculated by the finite element method (ANSYS) is approximately 4% lower than calculated analytically; the results of the calculation in SOFiSTiK differ by 2% from the results obtained in ANSYS; the discrepancy with the experimental data reaches 15%, and all frequencies calculated experimentally, greater than the frequencies calculated analytically or by the finite element method. The obtained frequency range of fiber-reinforced concrete airfield slabs is higher than that of concrete, which gives grounds to recommend fiber-reinforced concrete for the manufacture of structures that will operate under dynamic influences.