Dynamic Stability Analysis Of Single-story Steel Frames Under Vertical Cyclic Load

Steel frame structure is a kind of building structure with greater advantages, It is more and more widely used in practical engineering. The importance and application in practical engineering of steel frame structures promot the development of theoretical and experimental research. At present, the static stability theories and design methods of steel frame structure have tended to be perfect, but there is little research on the dynamic stability of steel frame, and the relevant theoretical research has not developed totally. Therefore, it has important theoretical and practical value to research on the dynamic stability of steel frame structures under cyclic loading.This article mainly studies the dynamic stability of steel frame structures under vertical cyclic loadings with different frequencies. The main research contents are stated as follows:(1) According to the relevant theory, this paper calculate the static critical load of single-story steel and its inherent frequency, and then derives the range of critical frequency corresponding to dynamic instability, thus obtain the dynamic unstable region.(2) The correctness of theoretical results are respectively verified by ANSYS eigenvalue buckling analysis and the modal analysis, and the critical frequency, corresponding to monolayer steel frame parametric resonance, can be obtained by the harmonic response analysis, and this value decides the selection of the frequency of cyclic load in the transient dynamic analysis.(3) This paper analyses the dynamic responses of single-story steel frame in general forced vibration, resonance and parametric resonance by AYSYS transient dynamic response, and selects two kinds of frequency in the general forced vibration. Then this article compares the differences of deformation when the structure in the regions of dynamic instability and dynamic stability, analyses the response of dynamic instability, and verifies the first three principal region of dynamic instability of the single-story steel frame structure.