Simulation Analysis For The Damage Identification Of Beam Bridge Based On Dynamic Measurement Method

The health state of bridge structure is the premise of communication working in gear. If there were any serious damages in bridge, it would influence on people's safety and losing of wealth. So it is very useful to research on the approach of damage detection of bridge structure.This article take small span beam bridge as research object and Introduced the common damage type beam bridge . In this background, how to test the state of bridge advance and diagnose the damage.In this paper, based on analyzing the present researches and existing problems of the dynamic method of the damage detection in bridge structures, several common dynamic methods of damage detection in structures are discussed, and the numerical simulation of damage detection is done on bridge structuresThe main tasks of this paper are:1.On the basis of studying domestic and abroad related literature, Have summarized the research overview and the method of the dynamic diagnose method of domestic and international systematically.2.Have introduced the common bridges injury disease, Analyze the characteristic of the Simple beam and continuously beam bridge's common diseases. And aims at the general damage research often take the simple model as the object. This article take the actual model as the object. and upgrade the simple damage beam with stiffness reduction element model in common research to simple damage beam with directional crack in this paper;3.utilize the national frequency change ration, Curvature mode, strain mode and flexibility difference etc.4 dynamic methods to diagnose these damage. And carries on the contrastive analysis to the result.This main research results of this article are:1.The damage of Hinge Joints will causes large scale reduces to the structure base frequency, And along with extent of damage's enlargement, the frequency drops obviously.2.The curvature mode and the strain mode are the sensitive recognition targets of damage and they have the good localization ability to the partial damage. But the curvature mode and strain mode can only distinguish the big damage when many damages are in the small scope. flexibility difference can diagnose except damage near the Support.3.The curvature mode and flexibility difference has bad anti-noise ability, this method can be suitable for the actual project only Under the guarantee measuring accuracy.This paper's findings indicated that use the natural frequency change degree can Judge the damage of hinge joints. Regarding to the partial damage, strain mode is recommended to carries on the recognition to the partial damages through the contrastive analysis to several kind of recognition target ,then the Health Status of bridge can be Judged Combine with the local test.