Development And Application Of Toolbox For Optimal Sensor Placement For Long-span Bridge Structural Health Monitoring System

The structural health monitoring system acts as a structural stethoscope,which is the guarantee for the safety and stability of the service of the large-span bridge structure,and the optimal placement of the sensor is the focus of scientific research in the bridge health monitoring system.In terms of sensor optimization and layout,the number of evaluation criteria proposed at home and abroad is numerous,and the original theoretical formula is more complicated.Considering the convenience of sensor placement in the actual engineering site,this project develops a MATLAB toolbox software that supports physical model reconstruction,measurement point selection,measurement point optimization calculation,result visualization display,and rapid report generation,namely OSPS toolbox(Optimal).Sensor Placement Strategy Toolbox)is used to guide engineers to optimize the placement of points in actual projects and provide decision-making basis.The main research work of this paper is as follows:(1)The evaluation criteria for the optimal placement of sensors for long-span bridges at home and abroad are systematically combed and summarized into single-objective optimization evaluation criteria and multi-objective optimization evaluation criteria.According to the engineering significance of the objective function of the single objective optimization criterion,it is divided into three categories,namely,the structural vibration signal is the strongest,the modal reconstruction effect is the best,and the parameter identification error is the smallest;the multi-objective optimization criterion is divided into the common multi-objective criterion and Pareto multi-target criteria.This topic implements the above guidelines to form a standalone MATLAB script file.(2)Based on the MATLAB GUI development platform,the interface layout and function modules of the OSPS toolbox are designed.Start with the user requirements,design software functions and implementation algorithms and methods,software main page layout design and module design,coding and debugging,program joint debugging and testing.Firstly,the outline design of the toolbox is carried out,including system component structure design,process flow design,module division,interface design,data path design and error design.Then the main function module is designed in detail,and the module design is divided into graphical user interface module.And optimize the layout calculation module,the former main control interface layout,model reconstruction,view zoom,report output and other functions,the latter master optimization calculation function.(3)The above design is programmed one by one to complete the modular layout of the toolbox.The MATLAB software and the commonly used finite element software and Office_Word interface program are built,so that the OSPS toolbox can recognize and read the model established in the common finite element software to provide preconditions for the visual output.In order to ensure the performance of the toolbox and enhance the user experience,the principles of simplicity,intuition,reduction of global variables,unified naming rules,setting prompt mechanism,and calling subprograms are followed in the process of programming implementation.Taking a Benchmark bridge finite element model as an example,the functional modules of the toolbox are verified,which proves that the operation is simple,the interface is friendly,the algorithm is integrated,and the output is visualized.(4)Applying the toolbox developed by this subject to the actual project,using the Midas finite element model of Shenyang Boguan Bridge as a real bridge example,modal analysis of the finite element model,sensor placement along the direction of the bridge using the OSPS toolbox And the results are compared and analyzed to further verify the feasibility of the OSPS toolbox and its practical engineering application value.