Pseudo Dynamic Test and Time-History Analyses of Traditional-Style Steel Frame Structures

Abstract

To study the seismic performances of steel frame structures in traditional-style buildings, the pseudo-dynamic test was carried out on a 1/2 ratio model built in the areas with a seismic design intensity of eight. The input earthquake waves included El Centro, Lanzhou and Wenchuan, and the maximum peak accelerations of these ground motions were 70, 200, 400 and 620 gal (0.7, 2, 4 and 6.2 m/s2). The seismic responses such as displacement, reaction force, acceleration were recorded. The hysteretic behavior, energy dissipation capacity, time-history curves of acceleration and displacement, bearing capacity and stiffness degradation were analyzed. The results show that the traditional-style steel frame structure stayed in the elastic stage subjected to no more than 400 gal (4 m/s2) PGA. There was no obvious pinch phenomenon in the hysteretic loops and the structural energy dissipation increased significantly with the increase of the seismic wave amplitude. When the 9-intensity seismic wave was applied, some unique members in traditional-style buildings yielded, and the spectral characteristic of the input seismic wave had a great influence on the seismic response of the structure. The modal analysis and time-history analyses were applied to the structure, the vertical deformation of the second and third modes of the steel frame was larger than that of the first modal shape, the reaction force value of finite element was a little larger than that of the test under the same loading condition. When the structure subjected to more severe earthquake, some unique members in traditional-style buildings acted as the first earthquake fortification line and dissipate most energy, and the structural most obvious reaction took place in advance or delayed a bit.