Damage Identification Based On The Correlation Coefficient Of Curvature Modal

Bridge is a kind of important infrastructure, it is very important to the development of local economy, and providing convenience for people’s daily life. In recent years, large bridges collapse continue occur, such accidents not only could bring huge economic losses, but also threaten people’s safety. So damage identification is becoming a hotspot for scholars.Today, after decades of development,the bridge damage identification got a great progress,such as sensor sensitivity increased, and damage related parameters have been found.Choicing method is also increasing, but still exist many problems. In this paper, conduct research on reinforced concrete beam.and with grey system theory,.curvature modal as a parameters for damage identification is selected. This paper discusses the use of the theoretical basis of curvature modal correlation coefficient to identify damage. At the same time, an improved correlation coefficient calculation method is proposed, this method avoids the resolution factor’s influence on the result. Using ANSYS softwarere to modeling the3D model for inforced concrete beams. Then, extracting displacement mode and curvature mode from this simulation. Using the correlation coefficient of curvature modal to calculate and dentify the damage. By comparing the different cases of correlation coefficient curve, the following conclusion is obtained:The more serious the structural damage, the greater correlation change, and the more obvious, then the degree of damage could be judged. Damage points closing to the nodes correlation coefficient is small, the damage point more far correlation is more close to1. So, the damage position can be judged.The next chapter is modal analysis experimental. Four subjects are2meter long reinforced concrete beam, one of them is intact beam, the other three is the damaged beam.Experimental method is as follows:by encouraging the experimental beam, measured its speed-time curve. To get the frequency of the structure-amplitude curves from Its FFT transform. Finally, it can be calculated that the modal curvature of structure by the peak detection and difference arithmetic.Then Illustrates the calculation steps, and by comparison with the other results further proved that the proposed in the previous chapter.