Improved Reversal Pushover Analysis Method Of Structures Based On The Seismic Energy Input Course Characteristics

As a method of static elasto-plastic Pushover Analysis has received wide attention because of its simple theory, convenient operation also can obtain the ideal results. Through Pushover Analysis the designer can obtain the location?order and scope of the plastic hinge which produced by structure under the action of horizontal force, so the designer can understand the failure process of the structure from the microeconomic perspective, which is helpful for designers to make more reasonable design scheme. At the same time compared with the time history analysis the amount of calculation by Pushover Analysis is greatly reduced, so it not only has a high theoretical value but also receives the favor in the eyes by the majority of designers in practical engineering application.However, traditional Pushover method has some deficiencies. Firstly, it just pays attention to the lateral deformation of structure and ignore the influence of earthquake duration and seismic energy input characteristics factors. Secondly the unidirectional loading pattern it adopted ignores the cumulative damage effects of the structure in the earthquake, also different horizontal force distribution pattern and even different direction of loading will have great influence on the calculation results.Therefore, aiming at the shortcomings of Pushover Analysis, combining the energy parameters and Pushover Analysis method, carried out the following research: 1) came up with the estimation method of ductility demand based on energy, obtain the curve of structure one-way energy dissipation by one-way Pushover Analysis, get the one-way energy demand curve through the deformation of structure, plotted the energy dissipation capacity curve and energy demand curves on the same coordinate, obtain the ductility demand through the intersection of the two curves; 2) on the basis of this, through discussing the impact of ductility coefficient of energy dissipation process, put forward the method that estimate the structure energy input process parameters through the ductility coefficient; 3) based on the ductility demand and structure energy input process parameters estimation method came up with the improved reciprocating Pushover Analysis method based on the deformation characteristics of the input process. It not only considers the deformation but also consider the earthquake duration and seismic energy input process characteristics of structural damage.Using finite element analysis software OpenSees established the model of 3 layer 3 cross and 6 layer 3 across, Take the Pushover Analysis based on the method, compared the calculation results with dynamic time history analysis results. Through comparing the maximum drift angle?cumulative hysteretic energy and its distribution? and the instantaneous deformation energy input course of reaction index, to verify the accuracy of the improved method.