Structural Dynamics Analysis In Performance-Based Earthquake Engineering

Current PBSD methods still lack efficiently tools and analysis procedure to show real structural dynamic behavior, which can't be expressed enough by SPO. Inherent difference between capacity curves and real structural nonlinear developing characters based on dynamic responses can not been eliminated at all. Demand diagram can't give the details of structural system. So it is very important to put more dynamics factors on current PBSD analysis tools or straightly putting forward efficient procedures into seismic performance evaluation and design. All the work is helpful for the accuracy and applicability of PBSD. The thesis'work concentrates on improving the current SPO and IDA procedure for better considering dynamics behaviors, the summarization as follows:The first, PBSD and PBEE's development in structural codes and engineering research is summarized. For its three properties and deficiencies, the opinion is proposed that more dynamic factors should be considered in current PBSD or PBEE analysis tools.The second, based on the current adaptive SPO lateral forces combined by multiple lateral force modes, the coupling lateral force modes during pushover analysis is proposed because of the equivalent damp ratio and period shift. The results from cases analysis shows that using coupling lateral force modes by CQC is more accurate than by SRSS, results from the improved method is more like that of nonlinear RHA. The difference between the SPO and CQC in the weak storey can be reduced in greatest degree.The third, the method of wrapping RHA programs is proposed, including the cases analysis for detecting local damage and evaluating structural seismic performance. The main point including:â‘ the computer analysis procedure for IDA is given in detail. The technology of wrapping RHA is realized by using DFPORT function, which is provided by C++or Fortran, and finish the work of the RHA program's being started up and the data's being collected and rewritten multiply.â‘¡Inherent difference in the results of SPO and IDA is compared,â‘¢method of interpolation based on IDA data is applied in comparing the maximum DM data under ultimate stage of IDA and SPO.â‘£the procedure of evaluating IDA results by fractile is given,and the difference methods is analyzed, by which the fractiles are calculated from DM to IM, or from DM to IM.At last, some work concentrates on the technology of summarizing different IDA curves, which are resulted by the diversity of seismic records. The improved method of summarizing IDA curves is proposed.â‘ The fork after yielding of elasto-plastic SDOF's IDA curves shows that the characters of seismic records will affect the plastic joints'nonlinear developing path based on the maximum dynamic responses. All that forms the new explanations for the discreteness of IDA curves and RHA results.â‘¡the method for comparing structural damage distribution along the nonlinear developments is proposed, which is based on the same key damage index. New method will produce more reasonable evaluation results about structural seismic performance.â‘¢Based on the two parameter intensity measure propose by Cordova, The improvement on calculating equivalent damage structure's period Tf and period shifting factor a produces better results of summarization for IDA curves.