Development And Application Of Software For Bridge Damage Detection Based On Modal Variation

In order to ensure that the bridge structure can be safely operated during service,it is particularly important to judge the occurrence of damage in a timely manner,evaluate the remaining service life of the structure,and adopt appropriate maintenance and repair programs.Therefore,damage identification technology is regarded as the core of the bridge structure health monitoring system.Among them,the damage identification method based on structural modal parameter variation has a clear concept and directly reflects the dynamic characteristics of the structure,which has attracted extensive attention from scholars.So far,a variety of damage identification methods have been proposed.However,due to the fact that the modal parameters of the actual bridge structure are often very complicated,the use of a single damage identification method is not enough to meet the needs of actual engineering,and a comprehensive and comprehensive damage identification system is urgently needed.Due to the large differences in application conditions and damage identification mechanisms of various methods,the identification effects are not the same.It is often difficult for engineering personnel to choose the most suitable identification method in practical applications,and it has high requirements for the professional quality of engineering personnel.In this topic,the damage identification methods are sorted and classified in detail.The existing damage identification methods based on modal variation are systematically summarized,the development process is sorted out,and the principles and theoretical derivation of each method are expounded.Use ANSYS software to establish a double-span continuous beam standard calculation model,simulate different damage conditions,compare the identification effects and advantages and disadvantages of each method,analyze the application limitations,and use M-files of MATLAB software to program each method and save it as function script that can be run independently.Relying on the APP Designer of MATLAB software,the interface layout and function realization of the bridge structure damage identification software are designed from the two aspects of software interaction interface and functional programming behavior.The software includes a total of 6 interactive interfaces,as the carrier of functions such as structural physical model reconstruction,modal parameter and sensitive modal calculation,damage judgment,damage location and visual output.Interfaces with MIDAS,ANSYS,ABAQUS finite element software and office software Word are built to realize one-key reconstruction of physical models and one-key export of identification reports.The software integrates 2 sensitive modal calculation methods,4 damage judgment methods and 32 damage location methods,and supports one or more methods for simultaneous calculation.And with the double-span continuous beam model built by ANSYS,the software's functional modules and operation process were verified,which proved that the software was convenient,friendly and efficient.Taking the Jiantiao Bridge in Zhejiang Province as the engineering background,the identification effect of the software in the actual project is verified.The finite element model of Jiantiao Bridge with two damages,is established with MIDAS CIVIL software.Select all the identification methods included in the damage identification software to identify the structural damage.The practicability and application of the damage detection software developed is further verified.