[0038] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation modes and specific operating procedures are given, but the scope of protection of the present invention is not limited to the following Mentioned examples.
[0039] This embodiment is mainly aimed at a damage detection and identification system established for long-span bridges with rail transit, such as railways, railways, and highways.
[0040] Such as figure 1 As shown, this embodiment includes two parts: a data acquisition subsystem and a data processing subsystem, where the data acquisition subsystem is built as figure 2 As shown, n acceleration sensors are uniformly distributed along the longitudinal center axis of the bridge, and the sensors are used to measure the acceleration of the vertical vibration of the bridge when vehicles pass, so that the bridge deck will be divided into n-1 standard damage identification areas; using NI The white-defined signal conditioning bus SCXI, as the signal conditioning module of the data acquisition subsystem, can well complete the simultaneous input and signal conditioning of multiple sensor signals. By amplifying, isolating and filtering the output signal of the sensor, it can adapt to the data. Mode conversion. The PXI module of NI is used as the signal acquisition module of the data acquisition subsystem to perform digital-to-analog conversion on the output signal of SCXI, combined with the software subsystem to complete data acquisition, recording, and analysis functions.
[0041] Such as figure 1 As shown, the data processing subsystem of this system consists of an auxiliary dynamic analysis module, a local information processing module, and a remote information processing module. Among them, the auxiliary dynamic analysis module provides the local information processing module with simulated dynamic load response signals during damage analysis; the telematics module uses the client/server (C/S) network mode and the local information processing module to construct remote data transmission And storage solutions. The following is a detailed introduction to the functional modules in the data processing subsystem:
[0042] (1) The auxiliary dynamic analysis module of the data processing subsystem is a dynamic analysis system for coupled vibration composed of a reference bridge numerical model and a rail vehicle numerical model. The coupled dynamic analysis model is such as image 3 As shown, the reference bridge numerical model and the rail vehicle model are established according to the spatial position, geometric size, material properties, and connection form of the components. The reference bridge numerical model is modal analysis and corrected, and conforms to the vibration characteristics of the tested bridge; the numerical value of the vehicle The model is a multi-degree-of-freedom dynamic system composed of multiple rigid bodies such as car body 1, bogie 2 and wheelset 3. The damping of the primary suspension device 4 and the secondary suspension device 5 are treated as linear viscous damping, and each rigid body The connection between them is an elastic connection, so that the entire vehicle has a total of 27 degrees of freedom, including ups and downs, yaw, head shaking, nodding, and rolling. The coupling between the wheel and the track is modeled by a three-dimensional dynamic contact method, which can simulate the jumping and derailment of the rail vehicle, which is more in line with the actual contact state between the wheel and the rail. Through the display integral solution, the dynamic load response signal of the simulated bridge can be obtained, and the initial data can be provided for the damage analysis of the bridge.
[0043] (2) The telematics module of the data processing subsystem is composed of a remote computer and a remote database. The remote computer is responsible for communicating with the local information processing module in a client/server (C/S) mode. The remote database is used to store static data such as time information, vehicle speed information, damage identification information, and dynamic data such as bridge detection dynamic load response signals and simulated dynamic load response signals.
[0044] (3) The local information processing module consists of a data display module, a signal reading module, a data management module, an analog signal reading and analysis module, a damage analysis module and a remote communication module:
[0045] a) Set an area (not the FIFO buffer on the data acquisition card) in the computer's memory through the signal reading module to temporarily store data, so as to solve the problem that the data is too late to display due to the large number of samples collected. After completing the initial setting of the sampling rate, the function of collecting the dynamic load response signal of the bridge in the hardware subsystem can be realized;
[0046] b) The data display module provides a graphical interface for the system to display monitoring data and damage identification results; in addition, through this module, the user can interact with other modules of the system;
[0047] c) The analog signal reading and analysis module, as the data exchange interface between the data processing subsystem and the dynamic auxiliary analysis module, can read the calculation results of the coupled vibration dynamic analysis system composed of the reference bridge numerical model and the rail vehicle numerical model , And parse the result into a bridge simulation dynamic load response signal that meets the calculation requirements of the damage identification module.
[0048] d) The damage analysis module is in accordance with Figure 4 The method shown realizes the judgment and identification of bridge damage. The bridge dynamic load response signal from the data acquisition module and the simulated dynamic load response signal from the auxiliary analysis software data exchange module will be read into the damage analysis module and processed according to the following principles:
[0049] First, simulate the dynamic load response signal f of the bridge s And detecting the dynamic load response signal f d Perform multi-scale wavelet packet decomposition:
[0050] C 1 i j , k ( t ) = ⟨ f s , ψ i j , k ( t ) ⟩ C 2 i j , k ( t ) = ⟨ f d , ψ i j , k ( t ) ⟩ ; i = 1,2 , . . .
[0051] Among them, C1 i j，k (t), C2 i j，k (t) is the wavelet packet coefficient, ψ i j , k ( t ) = 2 j / 2 ψ i ( 2 j t - k ) Is a wavelet packet function, i, j, and k are frequency parameters, scale parameters and translation parameters, respectively;
[0052] At each node (j, i) of the wavelet packet decomposition tree, the wavelet packet coefficient C1 i j , C2 i j And signal component S1 i j , S2 i j It can express the signal characteristics of the original signal in the j-scale i frequency range; it can be through the wavelet packet function ψ i j，k (t) Reconstruct to get the decomposition signal on each node:
[0053] S 1 i j = Σ k C 1 i j , k ψ i j , k ( t ) S 2 i j = Σ k C 2 i j , k ψ i j , k ( t )
[0054] The signal component energy on the corresponding node (j, i) is:
[0055] E 1 s i j ∫ t min t max [ S 1 i j ( t ) ] 2 dt E 2 s i j = ∫ t min t max [ S 2 i j ( t ) ] 2 dt
[0056] It can be seen that the signal component node energy gives the distribution characteristics of signal energy on different scales and frequency bands. Calculate the damage location index Damage according to the wavelet packet energy spectrum of each measuring point index , If the index is 0, the bridge is not damaged, otherwise, an alarm is issued and the damage location is determined.
[0057] e) The data management module, which adopts database technology for programming, can store the detection signal from the signal acquisition module and the analog signal from the auxiliary analysis software data exchange module. At the same time, data query, add, and delete operations are performed according to the request sent by the user, and the result of the operation is returned to the data display module.
[0058] f) The remote communication module is the communication interface between the local information processing module and the remote information processing module. It is constructed in a client/server (C/S) mode and transmits data according to the mechanism of real-time sending, timing sending and on-demand request . The data of the system is divided into static data (time information, vehicle speed information, damage identification information, etc.) and dynamic data (bridge detection dynamic load response signal and simulated dynamic load response signal), in order not to occupy the working time of the detection computer CPU, so that the application The program can run faster, when the data is transferred, the establishment such as Figure 5 Data communication model shown. Static data is realized by socket technology of TCP/IP protocol. During transmission, a unified data packet format is adopted as follows:
[0059] [Command Number]#@[数据1]#@[数据2]#@...[数据n]#@[送方]#@[Receiver], where "#@" is the delimiter of the data packet .
[0060] In order to ensure good real-time performance and higher data exchange rate, plus security measures such as access control management, the system dynamic load response data is implemented using NI's DataSocket transmission protocol.
[0061] It can be seen from the above that the data processing subsystem of this embodiment is developed and integrated using the VC++ platform. By reading the bridge dynamic load response signal detected by the data acquisition subsystem, combined with the bridge simulation dynamic load response signal calculated by the dynamic analysis module , Realize the damage identification of the bridge; realize the user's operation and data management of the system through the graphical interface and database technology; in addition, realize the communication between the local computer and the remote computer through the network technology. This embodiment has the characteristics of modularization and hierarchization, and each functional module can communicate with each other. The damage identification system takes into account the influence of inertia and vehicle vibration on the vehicle-bridge coupling and the time-varying nature of bridge damage under the load of moving vehicles, which improves the accuracy of bridge damage identification; signal acquisition does not affect the normal use of the bridge structure , It is easier to realize in engineering.
