Damage Identification Of Concrete Continuous Beam Bridges Based On Model Test Research

New methods for structrual damage identification have been developed recently in the fields of civil and aerospace structures. Unfortunenately, although most of these methods are well-discussed theoretically, many problems need to be solved when they are put into practice. So how to apply theories into practice must be further investigated. The following studies have been done in this thesis:1) The significance, content, method of structual damage identification in bridge and present domestic and worldwide research progress on structual damage identification are described. The main contents of the paper are concluded.2) Damage-identification theories that are comparatively mature are summerized and analysed. Historic and present researches on damage indexes are described.3) A finite element model (ideal experimental data) has been established through Ansys to test the damage-identification efficiencies of frequency mode indexes, coordinate mode indexes, curvature mode indexes, and flexibility indexes.4) The sensitivities of all those damage indexes to noise are analysed in order to futher validate the actual performance of those indexes and prepare for the experiment on continous beam model, and get advices and guidance on the experiment. The analysis result shows that the indexes of coordinate mode affirmance, the indexes of curvature mode, the indexes of flexibility, etc. are all highly sensitive to noise, which means these indexes are less efficient in damage identification when disturbed by noise.5) Experiments of the model of concrete continous beam are carried out to identify the damages of continous beam model and validate the damage-identification efficiencies of curvature mode indexes, and flexibility indexes. At last, the results of those experiments are summed up to tell what needs to be studied next.