| With the development of economy and the progress of science and technology,the construction of large-span space structure is increasing,the structure form is becoming more and more complex and the scale is becoming larger and larger.The construction of large-span space structure is an essential evaluation criterion for the scientific and technological level of national building and meanwhile is the requirement of modern civilization.It is widely used in important landmarks,such as stadiums,airport terminals and convention and exhibition centers.On the other hand,due to the aging of the materials,the uneven settlement of the foundation and the extreme external loads under strong earthquake and typhoon,these structures inevitably produce certain cumulative damages,and the extreme cases cause serious property loss and casualties.Therefore,it is not only of academic value but also of important practical significance to carry out Health Monitoring for large-span spatial structure.The Structural Health Monitoring System(SHMS)mainly collects data through the sensor system.After that,it will diagnose the data to determine whether there are damages,to find the damage position and damage degree and to evaluate physical conditions of the structure.Based on the AutoCAD platform,the paper integrated and developed a health monitoring system by using the secondary development tools of VBA,the mixed programming of MATLAB and VBA and Windows API.This paper also proved the practicability,stability and operability of the health monitoring system in the cases of square pyramid grid,Kiewitt type single-layer reticulated shell and the actual health monitoring project model for a gymnasium.The paper introduced the methods of sensor optimization and the criteria of sensor optimization.The paper researched the sensor optimization of its position through the Particle Swarm Optimization Algorithm that characterized by the advantages of high convergence speed and high search efficiency so as to obtain a more suitable method for sensor optimization.This paper introduced basic principles of particle swarm optimization,the selection of suitable function and key technology of visualization realization.Among them,threeparts of contents are described in key technology of visualization realization: the secondary development tools of VBA based on the AutoCAD platform,the mixed programming between MATLAB and VBA and the application of Windows API in VBA programming.The paper also introduced main designs of the spatial health monitoring system,including the system interface design and development,the structural model display module,sensor optimization layout module and health monitoring information module.It also provided a detailed introduction for the health monitoring system menu design,the main steps for interface development and the helping file of system.The detailed introduction for every module and function of health monitoring system is aimed at the software of a friendly interface,the using convenience,the stable operation and good extensibility.The validity of the health monitoring system is verified by the example of the quadrilateral pyramid grid,the Kaiwei type single-layer reticulated shell and the actual health monitoring project model of a gymnasium.The results show that:1)Health monitoring system owns the characteristics of friendly interface,the using convenience,the stable operation and good scalability.It has engineering practical value.Users can complete most of the process through the mouse and use the health monitoring system to learn and apply.2)Based on the toolbox developed by VBA tool of AutoCAD platform to make the calculating results visualized and present more intuitive and vividly in the AutoCAD mode,allowing users to interact the information of the dynamic observation of structural models,sensor optimization and health monitoring.On the one hand,it has maintained the powerful drawing function of AutoCAD and a good user interface;on the other hand,it has maintained its operability.3)Results of sensor optimization based on intelligent Particle Swarm Optimization Algorithm are stable and reliable,and the convergence is rapid.4)The use of mixed programming technology of VBA and MATLAB has greatly improved the memory management and operation speed of the application program,and has opened up a way for the rapid and efficient calculation of programs.5)The position of the optimal strain sensor and the acceleration sensor has symmetrical and obvious symmetry.6)It can be seen from the gymnasium health monitoring information module that it reaches its desired design goal when the maximum stress of steel structure stays at a reasonable design range after the roof is well installed.7)The maximum settlement of the stadium occurred at the center node,which means that the deflection value of the whole main truss was 52 mm.The actual deflection value was much smaller than the allowable deflection value.The structural rigidity was abundant and reached the desired value of the design.8)In the health monitoring information module,the sensor position can be displayed in the model by setting the type,the position and the number of sensor in the model.It can read the actual monitoring data of the structure sensor for the gymnasium,use Excel in CAD to display the monitoring data and show them to users in the form of images so that users can observe and analyze data results visually.It has realized the visualization of large-scale structure monitoring system,solved the problem of the current monitoring information which has non-intuitive image,poor and single performance and poor interactive functions and lacks intelligent automation treatment method.Therefore,it has practical values. |
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