Research On The Method For Optimal Sensor Placement And Inversion Of Void Parameters Of Sluice Floor On Soft Foundation Based On The Modal Flexibility-effective Independent Method

The Soft foundation sluice structure in the long-term operation process by the erosion of water flow will easily lead to the void of sluice floor and other problems,which seriously affects the normal operation of the sluice project and safety.therefore,the sluice base operating condition of safety monitoring to ensure the long-term safe operation of the sluice is of great significance.The sensor system is one of the most important parts of the monitoring of the void of sluice floor.The arrangement of sensors not only directly affects the accuracy of structural dynamic characteristic parameters testing,but also is a key step in the success of the vacant area of the sluice floor identification.In order to better solve the problem of the optimal arrangement of sensors with the objective of damage diagnosis,this paper proposes the method of optimal arrangement of sensors based on the modal flexibility-effective independent method,which only aiming at the defect that the traditional effective independent method does not consider the structural damage information.The research object is the Soft foundation sluice,and the damage type is the void of sluice floor.A combination of finite element numerical simulation and indoor physical model experiments is used to carry out research on the optimal arrangement of sensors of the dynamic inversion of the floor void of sluice on soft foundation,the main research content is as follows:(1)To address the problem that the traditional effective independent method only considers the linearly independent contribution of the measurement points to the target modal vector without considering the structural damage.Combined with the effect of the floor void of sluice on the modal parameters,the modal parameters sensitive to the floor void of sluice were selected as the damage sensitive quantity to correct the effective independent method.Optimal multi-objective sensor placement based on the introduction of damage sensitive feature quantities by the effective independence method,which also compares and analyses the applicability of each improved effective independence method.(2)The finite element model of the sluice is constructed and numerical simulations are carried out for different vacant conditions to analyze the optimal arrangement of sensors under two single-side vacant conditions for five sensor optimization methods.The overall evaluation of the effectiveness of the application of each method was carried out using four evaluation criteria.At the same time,in order to verify the feasibility of the sensor optimization method for the identification of the void parameters of the sluice on soft foundation.The modal parameters obtained from the sensors arranged with the five sensor optimization methods were used for the dynamic inversion of the floor void of sluice on soft foundation,and the results of the inversion of the void parameters of the five methods under two working conditions were compared and analyzed to verify the effectiveness of the method.(3)To further verify the effectiveness of the proposed method,an indoor physical model was created and vibration testing tests were conducted.The method proposed in this paper is used to calculate the optimal arrangement of sensors for the current situation of the floor void of sluice,and to determine the location of the measurement points.Also,the same number of measurement points were selected for random placement for comparative analysis.Finally,the modal parameters obtained from the two solutions were used to carry out the dynamic inversion of the floor void of sluice on soft foundation and compare the inversion results,which validates the feasibility of the method in practical engineering.