Application Of Dynamic Time Warping Algorithm In Ground Motion Selection

In recent years,earthquakes have become the most important natural disasters that endanger the safety of human life and property.Structural seismic resistance has become one of the research hotspots in various countries,which has promoted the rapid development of structural seismic field.Among them,the time-history response analysis method based on response spectrum theory has become a computational method required in the seismic design codes of many countries.By combing the methods of selecting ground motions at home and abroad,it is found that most of the traditional research methods are to select the best matching ground motions near certain sections(or periodic points)with the acceleration target design spectrum for the time-history response analysis of a certain structure.When the natural vibration period of the structure is different,the ground motion records need to be re-selected.Moreover,choosing different ground motion records for time-history response analysis of different building structures in the same proposed residential area according to the traditional research method.It does not accord with the common sense that the building structure in the same residential area should be affected by the same earthquake.In view of the limitations of traditional research methods,this paper proposes two methods for selecting ground motion records based on dynamic time warping algorithm according to different research objects and analysis purposes,and verifies the effectiveness of the two methods.The main contents of this paper include the following aspects:(1)The dynamic time warping algorithm is introduced into the field of seismic ground motion selection.The principle of dynamic time warping algorithm and its application in the field of ground motion selection are introduced.The reliability of using DTW distance as the standard parameter to measure the matching degree between acceleration response spectrum and acceleration target design spectrum is verified.(2)In view of the limitations of traditional research methods,this paper proposes a seismic database method to select ground motions by matching acceleration target design spectra in the whole period.The method is used to match a seismic database for each acceleration target design spectrum in the current code for seismic design of buildings in China.Establishing three frame structures with different natural vibration periods to verify the reliability of some seismic databases.(3)Taking two frame structures with different natural vibration periods in the same proposed residential area as examples,the application of ground motion databases in structural time-history response analysis is introduced.The results of ground motion selection and the results of time-history response analysis of two frame structures are compared in detail with the dual-band control method,which verifies the superiority of the method.(4)In order to meet the requirement of discreteness of time-history response analysis results for an important or special structure,a weighted DTW distance method based on dynamic time warping algorithm for selecting earthquake motions for a particular structure is proposed.The method is compared with seismic database method and dualband control method to verify the effectiveness of the method.