Real-time structural mechanical property monitoring method and device based on virtual-real combination

Abstract

The invention discloses a real-time structural mechanical property monitoring method and device based on virtual-real combination, and belongs to the technical field of mechanical property monitoring. The method comprises the following steps: constructing a mechanical property test platform, wherein the mechanical property test platform comprises a tested piece, a strain gauge, a data acquisition instrument and a computer for constructing a visual platform; parameters of a data acquisition instrument are set, and the data acquisition instrument obtains a strain signal of the strain gauge based on the parameters; the data acquisition instrument provides data for the computer based on UDP protocol parameters, the coordinate position of each key position after strain is determined, and the computer calls a fatigue algorithm to calculate the fatigue life of the tested piece; and displaying the geometric model of the tested piece, the coordinate position of each key position after strain and the fatigue life of the tested piece through a visual display platform. The mechanical property state of the structure can be monitored in real time.

Description

Technical Field

[0001] This application belongs to the technical field of mechanical property monitoring, and in particular, relates to a real-time monitoring method and device for structural mechanical properties based on the combination of virtual and real. Background Art

[0002] The structures of some devices to be measured are complex, and it is difficult to achieve real-time monitoring of their structural performance. Currently, the finite element method is mainly used for the structural performance analysis of such devices to be measured. However, the calculation time is long and the reduction degree of load boundaries is low, making it difficult to apply to the real-time online calculation of the performance of complex structures. Summary of the Invention

[0003] This application provides a real-time monitoring method and device for structural mechanical properties based on the combination of virtual and real to solve the above problems or at least partially solve the above problems.

[0004] In a first aspect, a real-time monitoring method for structural mechanical properties based on the combination of virtual and real is disclosed. The method includes:

[0005] Step S1: Construct a mechanical property test platform. The mechanical property test platform includes a test piece, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploy strain gauges at key positions of the test piece; connect the strain gauges to the strain gauge, connect the strain gauge to the data acquisition instrument, and connect the data acquisition instrument to the computer; wherein, the key positions are the structural strain concentration areas and the average distribution points on the surface of the test piece.

[0006] Step S2: Set the parameters of the data acquisition instrument. The data acquisition instrument obtains the strain signals of the strain gauge based on the parameters; the parameters include the sampling rate, block size, filtering parameters, and UDP protocol parameters, where the block size is the size of the data packet.

[0007] Step S3: The data acquisition instrument provides data to the computer based on the UDP protocol parameters, determines the strain data after deformation at each key position, and the computer calls the fatigue algorithm to calculate the fatigue life of the test piece; the geometric model of the test piece, the strain field distribution after deformation of the test piece, the coordinate positions after deformation at each key position, and the fatigue life of the test piece are displayed through the visualization display platform.

[0008] Preferably, in step S1, obtain the distances of each key position corresponding to the top of the test piece, number each key position in sequence based on the distances, and the larger the distance, the larger the number; take the key position with the smallest distance from the top of the test piece as the reference key position, numbered 0.

[0009] Preferably, the block size, sampling rate, and the reference value Δt1 of the delay time for the visualization display platform to receive data have the following relationship:

[0010]

[0011] Preferably, the test piece is a beam structure, and step S3: determining the coordinate positions of each key position after deformation includes:

[0012] Obtaining the coordinates (x 0 , y 0 ) of the reference key position after deformation, and obtaining the angle θ between the tangent line of the reference key position and the horizontal line 0 ;

[0013] For the key position numbered i + 1:

[0014] Obtaining the strain ε sensed by the strain gauge deployed at this key position i+1 ;

[0015] Calculating the angle θ between the tangent line of this key position and the horizontal line i+1 , where:

[0016]

[0017] Obtaining the adjacent key position of this key position, where the adjacent key position is a key position adjacent to this key position and with a distance from the top of the test piece less than the distance between this key position and the top of the test piece. The number of the adjacent key position is i, and the horizontal line is the structural center line in the horizontal direction when the beam structure is not deformed;

[0018] Obtaining the coordinates (x i , y i ) of the adjacent key position of this key position after deformation;

[0019] Obtaining the horizontal distance L of this key position relative to the adjacent key position of this key position, and calculating the coordinate position (x i+1 , y i+1 ) of this key position after strain occurs, where:

[0020]

[0021] where i is an integer greater than or equal to zero, and num is a variable.

[0022] Preferably, in step S3: the computer calls a fatigue algorithm to calculate the fatigue life of the test piece, including:

[0023]

[0024] where ε a is the total strain, ε ea is the elastic strain, ε pais the plastic strain, σ' f is the fatigue strength coefficient, ε' f is the fatigue ductility coefficient, E is Young's modulus, b is the fatigue strength exponent, c is the fatigue ductility exponent, and N is the fatigue life.

[0025] Preferably, displacement sensors and inclination sensors are also deployed at key positions of the test piece; the displacement sensors and inclination sensors are also connected to the strain gauge.

[0026] In a second aspect, a real-time monitoring device for the structural mechanical properties based on the combination of virtual and real is disclosed. The device includes:

[0027] Initialization module: configured to construct a mechanical property test platform, the mechanical property test platform including the test piece, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploying strain gauges at key positions of the test piece; connecting the strain gauges to the strain gauge, connecting the strain gauge to the data acquisition instrument, and connecting the data acquisition instrument to the computer; wherein, the key positions are the structural strain concentration regions and the structural surface average distribution points of the test piece;

[0028] Parameter setting module: configured to set the parameters of the data acquisition instrument, and the data acquisition instrument acquires the strain signal of the strain gauge based on the parameters; the parameters include the sampling rate, block size, filtering parameters, and UDP protocol parameters, wherein the block size is the size of the data packet;

[0029] Calculation module: configured to provide data from the data acquisition instrument to the computer based on the UDP protocol parameters, determine the strain data after deformation at each key position, the computer calls a fatigue algorithm to calculate the fatigue life of the test piece; display the geometric model of the test piece, the strain field distribution after deformation of the test piece, the coordinate positions after deformation at each key position, and the fatigue life of the test piece through a visualization display platform.

[0030] In a third aspect, an electronic device is disclosed. The electronic device includes:

[0031] at least one processor; and

[0032] a memory communicatively connected to the at least one processor; wherein,

[0033] the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method as described above.

[0034] In a fourth aspect, a non-transitory computer-readable storage medium storing computer instructions is disclosed, and the computer instructions are used to cause the computer to execute the method as described above.

[0035] The present application has the following technical effects:

[0036] Based on sensor measurement technology, data interaction technology, visualization platform construction technology, and fatigue algorithms, the present application is used to monitor the mechanical performance state of a structure in real time. During data acquisition, by setting UDP, sampling rate, block size, data filtering, etc., low-latency, multi-state, and wide-frequency domain transmission of data is achieved; by developing a data processing module and using multi-threading technology, efficient reception, parsing, and sending of data are realized, improving data processing efficiency; by integrating fatigue algorithms, the structural design of components is guided. Description of the Drawings

[0037] Figure 1 is a schematic flow chart of a real-time structural mechanics performance monitoring method based on the combination of virtual and real;

[0038] Figure 2 is a schematic architecture diagram of a real-time structural mechanics performance monitoring method based on the combination of virtual and real;

[0039] Figure 3 is a schematic diagram of the coordinate positions after strain occurs at key positions;

[0040] Figure 4 is another schematic flow chart of a real-time structural mechanics performance monitoring method based on the combination of virtual and real;

[0041] Figure 5 is a schematic structural diagram of a real-time structural mechanics performance monitoring device based on the combination of virtual and real. Detailed Embodiments

[0042] Explanation of Related Terms:

[0043] UDP: User Datagram Protocol, which provides a method for application programs to send encapsulated IP datagrams without establishing a connection.

[0044] Sampling rate: The amount of data collected per second.

[0045] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0046] As Figure 1 - Figure 2 shown, the present application provides a real-time structural mechanics performance monitoring method based on the combination of virtual and real, and the method includes:

[0047] Step S1: Construct a mechanical property test platform, which includes a test piece, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploy strain gauges at key positions of the test piece; connect the strain gauges to the strain gauge, connect the strain gauge to the data acquisition instrument, and connect the data acquisition instrument to the computer; wherein, the key positions are the structural strain concentration areas and the average distribution points on the surface of the test piece.

[0048] Step S2: Set the parameters of the data acquisition instrument, and the data acquisition instrument obtains the strain signal of the strain gauge based on the parameters; the parameters include the sampling rate, block size, filtering parameters, and UDP protocol parameters, wherein the block size is the size of the data packet.

[0049] Step S3: The data acquisition instrument provides data to the computer based on the UDP protocol parameters, determines the strain data after deformation at each key position, and the computer calls the fatigue algorithm to calculate the fatigue life of the test piece; the geometric model of the test piece, the strain field distribution after deformation of the test piece, the coordinate positions after deformation at each key position, and the fatigue life of the test piece are displayed through the visualization display platform.

[0050] In the said Step S1, obtain the distances of each key position corresponding to the top end of the test piece, number each key position in sequence based on the distances, and the larger the distance, the larger the number; take the key position with the smallest distance from the top end of the test piece as the reference key position, numbered 0.

[0051] The block size, sampling rate, and the reference value Δt1 of the delay time for the visualization display platform to receive data have the following relationship:

[0052]

[0053] The high-pass filter reference value of the test piece under impact conditions is greater than the high-pass filter reference value under static load conditions. For example, when a static load is applied to the test piece, the high-pass filter is set to the minimum value of 0.05 Hz to obtain wide-frequency domain data and achieve real-time data interaction between the visualization platform and the data acquisition end.

[0054] In the said Step S1, obtain the distances of each key position corresponding to the top end of the test piece, number each key position in sequence based on the distances, and the larger the distance, the larger the number; take the key position with the smallest distance from the top end of the test piece as the reference key position, numbered 0.

[0055] As Figure 3 shown, the test piece is a beam structure, and in the said Step S3: determining the coordinate positions after deformation at each key position includes:

[0056] Obtain the coordinates (x 0, y 0 ), obtain the included angle θ between the tangent line of the reference key position and the horizontal line 0 ;

[0057] For the key position numbered i + 1:

[0058] Obtain the strain ε sensed by the strain gauge deployed at this key position i+1 ;

[0059] Calculate the included angle θ between the tangent line of this key position and the horizontal line i+1 , where:

[0060]

[0061] Obtain the adjacent key position of this key position. The adjacent key position is the key position adjacent to this key position and with a distance from the top of the test piece less than the distance between this key position and the top of the test piece. The number of the adjacent key position is i, and the horizontal line is the structural center line in the horizontal direction when the beam - type structure is not deformed;

[0062] Obtain the coordinates (x i , y i ) of the deformed adjacent key position of this key position;

[0063] Obtain the horizontal distance L between this key position and its adjacent key position, and calculate the coordinate position (x i+1 , y i+1 ) after the strain occurs at this key position, where:

[0064]

[0065] where i is an integer greater than or equal to zero, and num is a variable.

[0066] In this application, when the beam - type structure undergoes elastic deformation, the displacement or coordinate information of the key position can be obtained through strain. The method for determining the coordinate positions of each key position after deformation in this application can reduce the number of displacement sensors arranged, thereby reducing the size of data packets and further reducing the delay time from the data acquisition end to the computer.

[0067] In this application, the acquisition mode of the data acquisition instrument needs to match the type of the acquired signal. The input mode of the strain signal is DC_SingledEnd, and the physical dimension is StrainGage. The high-pass cut-off frequency affects the data acquisition under static load conditions. To achieve real-time data interaction between the visualization platform and the data acquisition end, in the static load condition, the minimum value of 0.05HZ in the data acquisition instrument is selected in this application to ensure that the device can collect the signal values in the low-frequency section. The values of the sampling rate and the block size are related to the delay time of the monitored signal. In this application, the sampling rate is set to 512Hz, the block size is 32, and the reference value of the delay time is Δt 1 is 62.5ms. The UDP transmission protocol function of the data processing software port is enabled to send the device channel data to the specified UDP function and configure the corresponding transmission parameters, such as the IP address and the port number. There is also data processing software supporting the data acquisition instrument.

[0068] Step S3: The computer calls the fatigue algorithm to calculate the fatigue life of the test piece, including:

[0069]

[0070] where ε a is the total strain, ε ea is the elastic strain, ε pa is the plastic strain, σ' f is the fatigue strength coefficient, ε' f is the fatigue ductility coefficient, E is the Young's modulus, b is the fatigue strength exponent, c is the fatigue ductility exponent, and N is the fatigue life.

[0071] In this application, the UE is used to build a visualization display platform, construct the geometric model of the test piece, and then perform functions such as algorithm integration, visualization interface display, test result loading and interactive display, etc., to present the geometric and physical forms of the operating equipment. Generate a load spectrum, select a fatigue algorithm matching the material and working conditions of the test piece, perform damage calculation, and obtain the fatigue life of the test piece.

[0072] Set the local machine and the target IP for sending, the receiving and sending target port numbers at the receiving end of the UE platform, and select the data source at the same time; the three-dimensional display module supports the display and management of the physical field type and the geometric model, and draws and displays the mechanical field type in the physical field on the geometric model. The specific implementation is as follows: Set the number and location of the sensor measurement points in the three-dimensional geometric model, and form a physical field in the geometric model by using interpolation and smooth transition techniques according to the positions of each measurement point. The parameter values of each measurement point can be interactively set through external data and the display effect of the physical field can be updated in real time according to the data values. The visualization display module can include model import, which is used to support the import of CAD physical models and assembly models, and includes a material system for creating various physical fields, such as temperature, stress, etc.

[0073] After the measured component is deformed, the stress state of the structure will change. Through sensing measurement, the change of performance parameters caused by the structural deformation can be obtained. Combining with data interaction technology, the processing of sensor data can be realized. Based on visualization technology, the mechanical properties of the structure are presented in the form of a numerical cloud map on the geometric structure, realizing the real-time monitoring of the structural mechanical property state. In this application, by selecting typical positions of the test piece, sensors are configured. The signal change during structural deformation is measured by the sensors. After the sensing data is processed by a charge amplifier or a strain gauge, it is collected by data acquisition software. Finally, by enabling the UDP function and combining with data interaction technology, it is transmitted to the visualization display platform. By integrating the fatigue algorithm, the fatigue life of the test piece in a certain state is calculated, realizing the real-time online of the sensing data, predicting the fatigue life of the structural component, and finally forming a real-time monitoring technology for structural mechanical properties based on the combination of virtual (digital model) and real (physical entity). In the existing structural performance monitoring based on digital twins, there are few studies on data transmission technology through opening the UDP function of the data acquisition instrument, few studies on reducing the delay time, and few studies on calculating the fatigue life based on real-time data and combining with the fatigue algorithm.

[0074] This application aims to propose a method for real-time monitoring of structural mechanical properties based on sensor measurement technology, data interaction technology, visualization platform construction technology, and fatigue algorithm. Its main feature is to obtain the sensing data at the key positions of the structure by building a structural mechanical property test platform, use the data acquisition instrument for data acquisition and transmission, realize data reception, parsing, and sending through data processing, display the structural performance of the operating equipment based on the visualization display platform, and calculate and display the fatigue life of the structure by integrating the fatigue algorithm. Among them, the sampling rate and block size of the data acquisition instrument can be adjusted, and the delay can be adjusted by integrating the strain generation position coordinate algorithm; by performing filtering settings, broadband domain data can be obtained; in data interaction, this application adopts multi-threaded technology and uses multi-threaded technology to improve the data processing efficiency.

[0075] If the multi-threaded delay time is Δt2, then the total delay time Δt is:

[0076]

[0077] This application has the following advantages:

[0078] 1. Carry out the acquisition of sensing data of the test piece, and provide input for the data receiving end by opening the UDP function;

[0079] 2. Use the filtering method to collect the sensing data in the required frequency domain;

[0080] 3. Reduce the latency time by using the sampling rate and block size; integrate the strain generation position coordinate algorithm to reduce the number of sensors used and the size of data packets, thereby reducing the latency time; utilize multi-threading technology to improve the data processing efficiency;

[0081] 4. Use the Microsoft Visual Studio development platform to develop a data processing module to achieve data reception, data parsing, and data transmission;

[0082] 5. Conduct structural state detection based on the visualization display platform and the mechanical performance test platform, and change the display contrast of mechanical properties by modifying numerical thresholds, display algorithms, etc.;

[0083] 6. Based on real-time sensing data, with stress or strain as the input, calculate the fatigue life under a certain working condition based on the fatigue algorithm to guide the structural design.

[0084] 7. This method has generalizability. For example, it can display the structural temperature field or pressure field, and the sensors can be displacement sensors or inclination sensors.

[0085] As Figure 5 shown, the present application provides a real-time monitoring device for structural mechanical properties based on the combination of virtual and real. The device includes:

[0086] Initialization module: Configured to construct a mechanical performance test platform. The mechanical performance test platform includes a test piece, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploy strain gauges at key positions of the test piece; connect the strain gauges to the strain gauge, connect the strain gauge to the data acquisition instrument, and connect the data acquisition instrument to the computer; wherein, the key positions are the structural strain concentration areas and the average distribution points on the surface of the test piece;

[0087] Parameter setting module: Configured to set the parameters of the data acquisition instrument. The data acquisition instrument obtains the strain signal of the strain gauge based on the parameters; the parameters include the sampling rate, block size, filtering parameters, and UDP protocol parameters, where the block size is the size of the data packet;

[0088] Calculation module: Configured such that the data acquisition instrument provides data to the computer based on the UDP protocol parameters, determines the strain data after deformation at each key position, and the computer calls the fatigue algorithm to calculate the fatigue life of the test piece; display the geometric model of the test piece, the strain field distribution after deformation of the test piece, the coordinate positions after deformation at each key position, and the fatigue life of the test piece through the visualization display platform.

[0089] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A real-time monitoring method for structural mechanical properties based on virtual-real combination, characterized in that: The method comprises: Step S1: construct a mechanical properties testing platform, which includes a tested object, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploy strain gauges at key positions of the tested object; connect the strain gauges to the strain gauges, connect the strain gauges to the data acquisition instrument, and connect the data acquisition instrument to the computer; wherein the key positions are the structural strain concentration areas and the average distribution points on the structural surface of the tested object; Step S2: setting parameters of the data acquisition instrument, based on which the data acquisition instrument acquires the strain signal of the strain gauge; the parameters include sampling rate, block size, filtering parameters and UDP protocol parameters, wherein the block size is the size of the data packet; Step S3: The data acquisition instrument provides data to the computer based on the UDP protocol parameters to determine the strain data of each key position after deformation. The computer calls the fatigue algorithm to calculate the fatigue life of the test piece; the geometric model of the test piece, the strain field distribution of the test piece after deformation, the coordinate position of each key position after deformation and the fatigue life of the test piece are displayed through the visual display platform.

2. The method according to claim 1, characterized in that In step S1, the distance between each key position and the top of the tested object is obtained, and each key position is numbered in sequence based on the distance, with the larger the distance, the larger the number; the key position with the smallest distance to the top of the tested object is used as the reference key position, which is numbered 0.

3. The method according to claim 1, characterized in that The relationship between the block size, sampling rate and the reference value Δt1 of the delay time for the visualization display platform to receive data is as follows:

4. The method according to claim 2, characterized in that The tested piece is a beam structure, and the step S3: determining the coordinate position of each key position after deformation includes: Obtain the coordinates (x0, y0) of the benchmark key position after deformation, and obtain the angle θ0 of the tangent line of the benchmark key position relative to the horizontal line; For the key position numbered i+1: Get the strain ε sensed by the strain gauge deployed at the key position i+1 ; Calculate the angle θ between the tangent line at the key position and the horizontal line i+1 ,in: Obtaining an adjacent key position of the key position, wherein the adjacent key position is a key position adjacent to the key position and having a distance from the top of the tested piece smaller than the distance between the key position and the top of the tested piece, the adjacent key position is numbered i, and the horizontal line is the structural center line of the beam structure in the horizontal direction when the beam structure is not deformed; Get the deformed coordinates (x i ,y i ); Obtain the horizontal distance L of the key position relative to the adjacent key position of the key position, and calculate the coordinate position (x i+1 ,y i+1 ),in: Where i is an integer greater than or equal to zero, and num is a variable.

5. The method according to claim 1, characterized in that The step S3: the computer calls a fatigue algorithm to calculate the fatigue life of the tested piece, including: Among them, ε a is the total strain, ε ea is the elastic strain, ε pa is the plastic strain, σ' f is the fatigue strength coefficient, ε' f is the fatigue continuation coefficient, E is Young's modulus, b is the fatigue strength index, c is the fatigue continuation index, and N is the fatigue life.

6. The method according to any one of claims 1 to 5, characterized in that Displacement sensors and inclination sensors are also deployed at key positions of the tested piece; the displacement sensors and inclination sensors are also connected to the strain gauge.

7. A real-time monitoring device for structural mechanical properties based on virtual-real combination, characterized in that: The device comprises: Initialization module: configured to build a mechanical properties test platform, which includes a test piece, a strain gauge, a data acquisition instrument, and a computer for building a visualization platform; deploy strain gauges at key positions of the test piece; connect the strain gauges to the strain gauges, connect the strain gauges to the data acquisition instrument, and connect the data acquisition instrument to the computer; wherein the key positions are the structural strain concentration areas and the average distribution points on the structural surface of the test piece; Parameter setting module: configured to set parameters of the data acquisition instrument, based on which the data acquisition instrument acquires the strain signal of the strain gauge; the parameters include sampling rate, block size, filtering parameters and UDP protocol parameters, wherein the block size is the size of the data packet; Calculation module: configured as a data acquisition instrument to provide data to the computer based on UDP protocol parameters, determine the strain data of each key position after deformation, and the computer calls the fatigue algorithm to calculate the fatigue life of the test piece; display the geometric model of the test piece, the strain field distribution of the test piece after deformation, the coordinate position of each key position after deformation and the fatigue life of the test piece through a visual display platform.

8. A computer-readable storage medium, wherein a plurality of instructions are stored in the storage medium; the plurality of instructions are used for a processor to load and execute the method as claimed in any one of claims 1 to 6.

9. An electronic device, characterized in that: The electronic device comprises: A processor, which is used to execute multiple instructions; A memory for storing a plurality of instructions; The plurality of instructions are used to be stored in the memory and loaded and executed by the processor according to any one of claims 1 to 6.

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