Research On The Damage Identification Of Bridge Structures Based On Time-Domain Method

Structure damage identification is a newly arisen research direction in the field of Civil Engineering, however, there are no uniform theories and methods available because this research is still at the beginning period. Up to now, some so-called methods are still unable to offer excellent solutions to structure damage identification problems under the condition that measuring data are incomplete and inaccurate. With such a background, this dissertation will emphasize on the reseach of the time-domain damage identification methods under inaccurate and imcomplete conditions.Firstly, being a theoretical foundation for the whole research work, a systematic summary and conclusion of basic theories according to time-domain method damage identification is made, from which the basic theories of this dissertation form. It mainly introduces identification theories, identification principles and identification algorithms in time-domain method damage identification. In the part of identification algorithms, identification algorithm about least square method is primarily talked about, including basic least square method, recursive least square method and adaptable least square method.Secondly, there is an introduction of some practical algorithms of time-domain damage identification methods have been done, regarding bridge damage identification as the research target. Some researches of specific time-domain damage identification methods, from basic least square methods with complete input and output information, compensative least square method with some input information unknown, to iterative least square method without input information. In order to get rid of the problems of excessive solve scale and incompatible problem about solutions, static condensation method and optimization algorithm are employed in this part.Lastly, there are numerical verifications about damage identification methods mentioned in this dissertation. Separately, take examples of a simply supported beam bridge and a continuous girder bridge. From those examples, identification...