Study On Distribution Pattern Of Lateral Force In Earthquake Response Of Structure

Pushover analysis is a simplified method for structure seismic evaluation, which is widely used, and is recommended as the new national code of seismic design of buildings. The lateral load pattern selection is one of the critical issues in pushover analysis, especially when the higher modes influence is important . In this study, the procedure of Pushover analysis has been put into effect, and following factors have been mainly researched in Pushover analysis: choosing the calculation model of both structure and element; analyzing the yielding moment and limiting moment of cross section; posing the distribution pattern of lateral force; discussing the influence of high class mode of vibration on the structure. The following conclusions are given by analyzing a frame damaged by the seismic load with the help of the an ANSYS software: (1) The calculation accuracy of the displacement of different stories and the whole reaction under the distribution of even lateral force is the lowest. (2) In the structure of elastic stage, the calculation accuracy under the distribution of high equivalence and elastic multi-mode combination is higher than that under the distribution of del; while in the structure of plastic stage, the result is opposite. (3) In the structure of elastic stage, compared with the distribution of fixed lateral force, self-adaptation distribution can't improve the calculation accuracy of the displacement of different stories; but in the structure of plastic stage, the calculation accuracy under the distribution of self-adaptation distribution is highest. (4) The adaptable loading pattern is more reasonable than fixed loading pattern because it takes the structure dynamic properties into account, however, fixed loading pattern could be used in comparatively regular structure. (5) In judging the aseismic ability of structure, it is advisable to combine the capacity curve in terms of top roof displacement and base-shear with the displacement of different stories and the distribution of plastic hinges.