Study On Evaluation Method Of Damage For Structures Under Earthquakes

The incremental feature was a very famous character of concrete material. In different load cases, damages of structures or members of concrete were born and incremental, which was an essence of collapse of structures. On the base of studying on defects of current evaluation modals of damage under the earthquake, it was advised a new seismic damage evaluation modal and results of experiment were used to prove the feasibility of the model proposed in this paper. Finally, it was valued the global damage of a structure under the earthquake based on the selection of seismic wave.By taking the hysteretic behavior and complexity of earthquake into account, the process of earthquake was simplified as a"black box", and the hysteretic behavior was changed into two states: static and ending. Therefore, the skeleton curve was simplified in the form of double-folded line, and the stiffness degradation was considered. Then, an evaluation model of the seismic damage was built in the form of elastic energy. According to experimental results of four high-strength RC columns, comparisons were made between results of experiments and by the way advised in this paper, which was used to show the feasibility of the new model.Moreover, experimental results of HRB400 grade reinforce concrete columns were used to value the damage of columns based on the method of ductility coefficient and classic damage evaluation. Then, comparison was carried out between the evaluation and experiment. Considered the difficulty of computing ductility coefficient, a method for the colculation was studied. Another caculational method for incremental disspated hysteretic energy applied in the classic damage evaluation model under earthquake, was probed from the factors of cycle numbers and the maximum displacement in the process of cycle.Finally, aimed to the selection method of seismic wave that was the first problem of the time-history analysis,it was tried to make the way of selection wave perfectly, based on the current way in this paper. Because duration was not considered in the current way of wave selection, the elastic total input energy was supplied to build a new way. Then, the analysis soft—IDARC was used to analyze, and the results were compared between the wave selected by the way in this paper and the wave selected by the usual way, which was showed that the way selected the wave in this paper was corrective and feasibility.