Research On Damage Identification Of Structure By Vibration Test Technology

As an important place for people production and living practices, civil engineering structure is related to people's daily life and safety. During using, civil engineering structure is vulnerable to a wide variety of loads, such as earthquakes, typhoons, floods, overloading,fatigue damage and other disasters, making structure damage, even the fatal structure collapse,which threats people's life and property security. As a result, people are increasingly concerned about the health of the structure.Structural damage analysis theory is yet to mature, but still has certain limitations, such as the amount of measuring point, data, etc. which will result in the large work of structural damage analysis and computational complexity. Consequently, it does not apply to large structures. In addition, a lot of structural damage facts show that the vibration of structure damage not only has horizontal and vertical movements but torsional movements. Especially for irregular structure which has uneven distribution of stiffness, mass eccentricity, its torsional response is more intense. Therefore, the search for the vibration test technology and analysis methods for multidimensional structure of vibration damage analysis has significant meaning. Based on this point, from the shallower to the deeper, this paper combines with typical project structure, inherits and masters the existing theories and methods, and then combines with the existing testing techniques, highlighting the advantages of wireless sensors,and finally uses the wavelet image compression technology, the new test system called multidimensional vibration experimental system to make damage analysis in many aspects.Main contents of this paper are as follows:1. Through two examples of typical structural damage identification analysis, it determines the damage location, uses the existing damage technical theory to prove the validity of existing theories, and puts forward the existing damage technical theory not suited to large structures with limitation of complex computing, difficult computing, low application efficiency.2. For the problem of a large number of sensor cable wiring, inconvenient use and other issues, it applies the method of structure damage identification based on test technology of wireless sensor. Using wireless sensors to extract the vibration response of the structure under different cases helps damage identification. Compared to wired sensors, wireless sensors areconvenient to use without a lot of wirings, and with the advantages of small size, light quality,fast data storage, easy use in particular case.3. For the problem of huge amount of data, difficult computing and other difficult issues,it puts forward the method of structure damage identification based on wavelet transform image compression technology.This method can quickly deal with large amounts of information of large-scale structures.It can be extracted key features by temporal compression by transverse and longitudinal modes of information. It can use a very small amount of data that summarizes the structural dynamic response characteristics to transform into a two-dimensional image by analysis of the relationship between the response and the damage in order to guarantee rapid damage identification.4. In special situation, when the real structure twists significantly, structural torsional effect cannot be ignored. The traditional structure of the test system does not apply to other issues including significant torsional effect. Therefore, it puts forward the new test system called multidimensional vibration experimental system to get torsional response and make damage identification. The new system takes the torsional effect of structure into account. It can extract multidimensional structure of torsional vibration response. Using the system to get the torsional response of structure and make damage identification and analysis, it will be more comprehensive.