Development And Design Of Health Monitoring And Early Warning System For Spatial Truss Structure Based On Excel VBA Program

With the rapid development of long-span space structure,people pay close attention to the safety of building structure.Therefore,it is of great significance to monitor the real-time health status of the structure.Taking the elevated station house of Harbin railway station reconstruction project as the research object,this paper designs the corresponding structural health monitoring system.Using finite element software,finite element analysis model was established for steel tube truss structure,and static analysis was carried out on the structure.Finally,macro language programming was used for secondary development to realize real-time data display and automatic early warning function,providing reference and guarantee for structural safety and stability in the operation of Harbin station.The main research contents are as follows:(1)The finite element software ANSYS was used to establish the steel tubular truss structure model.Combined with the actual load bearing condition of the truss structure,the strain and deformation of the truss structure under the action of dead weight load and constant load of installation equipment were analyzed.The vertical displacement and axial stress of truss structure are calculated by numerical simulation.In addition,the bar element at the key position of the sensor of truss structure is extracted to accurately calculate the axial stress variation,and the numerical simulation strain data sheet of all measuring points is obtained.(2)Design and plan the overall design principles of the spatial steel tube truss structure of Harbin station,and summarize the functions and objectives of the monitoring system according to the project requirements.Based on the principle of fiber Bragg grating sensor and the actual situation of Harbin steel tube truss structure,the number and position of fiber Bragg grating strain sensor,temperature sensor and displacement sensor were determined according to the principle of sensor setting.At the same time,the construction and installation methods in complex environments such as high-altitude operation are considered,and the expected results are achieved in the actual construction process.(3)According to the data obtained by numerical simulation of truss structure and the measured data of fiber Bragg grating sensor,the function of feature data recognition and data call is realized by using ExceL VBA program.Through VB module macro language development tools,in the VBE development environment to write relevant code procedures,and achieve the sensor data output module system docking.By studying the data output characteristics of the sensor operating system and the repeated test of the VBA program,the functions of real-time data call and absolute value range judgment are finally realized.(4)According to the design requirements of the health monitoring system of steel tube truss structure in the elevated station house of Harbin railway station renovation project,the data acquisition system was debugged and the window login interface and operation interface of the health monitoring system of Harbin railway station structure were designed.The functions of data timing storage,real-time warning and visualization of the location of measurement points are realized.After a long period of regular monitoring,through observing the fluctuation of data,the influence of wind load and snow load,temperature change,peak and low peak of carrying capacity on the structure was evaluated.At the same time,the reliability and stability of the software system are verified.