Abstract:We examine structure strong motion observation records from the Ludian MS6.5 and Yao’an MS6.0 earthquakes, as recorded by a structure seismic response array in Yunnan province. Fourier spectrum analysis shows that 1.7 Hz is the natural frequency of the first vibration mode, and 2.1 Hz is the natural frequency of the second, which is a torsional mode. Comparing strong motion records of the two earthquakes, we infer that the torsional vibration of Ludian is much stronger than Yao’an. In addition, we establish a 3D finite element model using SAP2000, selecting strong motion records as input motion to simulate the seismic performance of structure. Time history analysis shows that the structure’s performance is consistence with Fourier spectrum analysis. In summary, we think that the input motion angle is an important aspect to the torsional vibration of structure.
WEI Yong,CUI Jianwen,WANG Qiuliang et al. The Influence of Input Ground Motion Direction on Structure Torsional Vibration[J]. jgg, 2018, 38(12): 1306-1310.