Natural-frequency Analysis of Two-Roof Steel Frames via the Finite Element Method

Steel frame structures are widely used in the fields of mechanics and construction, such as in factories and workshops with many different sizes and structures. Therefore, it is necessary to calculate the strength, stiffness, and stability of the frame structure, thereby determining the critical size and critical force that a structure can withstand. However, in reality, there are sometimes cyclical loads such as vibrations caused by compactors, vibrations caused by impacts, or by machines operating in the factory; in such cases, if the oscillation frequency of the load coincides with the free oscillation frequency of the frame, resonance may occur, which has a very harmful effect on the structure. Therefore, calculating and determining the oscillation frequency and the specific oscillation form of the frame structure will be the basis for avoiding resonance; or taking remedial measures when it occurs. In this study, the finite element method is used to determine the natural oscillation frequency and draw the corresponding natural oscillation forms of two-roof steel frames. In addition, the influence of geometric dimensions on the natural vibration mode of the beam is also calculated in this study. The calculation results can be used in the future to design structures with two-roof steel frame models.