Scientific paper ID 1952 : 2020/3

When installing new equipment, accompanied by dynamic effects on an existing steel structure, it arises the question about avoiding resonance phenomena. The subject problem of this paper is changing existing structure’s natural frequency within certain limits. A steel plate strengthened with a rod system (sprung) is considered. It is determined an effective area of natural frequency’s variation of the slab, as part of the combined system.There is solved example problem. With set geometrical and mechanical parameters it is determined the tensile strength of the diagonal element.