A system and method for identifying prestress loss in concrete frame structures

Abstract

The present invention relates to the field of concrete identification technology, and specifically discloses a system and method for identifying prestress loss in a concrete frame structure. The method comprises querying a concrete frame model, selecting embedded points within the frame model, and selecting patch points on the surface of the frame model; obtaining prestress based on the embedded points, obtaining strain based on the patch points, and verifying the prestress based on the strain; counting the prestress containing the points after verification at each moment, performing spatial domain processing and time domain processing on the prestress, and determining the amount of loss; and adjusting the application frequency of the embedded points based on the loss determination result. The present invention sets embedded points and patch points, obtains prestress from the embedded points, and obtains strain from the patch points. The strain is used to verify the prestress, rather than calculate the prestress, greatly improving the accuracy of the prestress monitoring results, thereby improving the accuracy of the loss calculation.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete identification, and in particular to a system and method for identifying prestress loss in a concrete frame structure. Background Art

[0002] Prestress monitoring of concrete frame structures is usually to understand the actual effect, long-term changes, losses, and whether there are any structural safety hazards of applying prestress in the structure.

[0003] Most existing detection methods use patch sensors to obtain strain, then infer prestress, and then calculate the loss. This involves a one-step strain-to-prestress simulation process, and the accuracy cannot reach 100%. Therefore, in some testing situations where precision is required, the accuracy of the method using only patch sensors for calculation is difficult to meet the standard. Therefore, how to improve the accuracy of the prestress identification process is the technical problem that the technical solution of the present invention aims to solve. Summary of the Invention

[0004] The object of the present invention is to provide a system and method for identifying prestress loss in a concrete frame structure to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for identifying prestress loss in a concrete frame structure, the method comprising:

[0007] Query the concrete frame model, select embedded points within the frame model, and select patch points on the surface of the frame model;

[0008] Acquire prestress based on embedded points, acquire strain based on patch points, and verify prestress based on the strain; wherein the acquired prestress contains a time tag and a position tag, and the acquired strain contains a time tag and a position tag;

[0009] Count the prestress at each moment after verification, process the prestress in the spatial domain and the time domain to determine the loss amount;

[0010] The application frequency of the embedded points is adjusted according to the loss amount determination results.

[0011] As a further solution of the present invention: the steps of querying the concrete frame model, selecting embedded points in the frame model, and selecting patch points on the surface of the frame model include:

[0012] Query the concrete frame model and its pouring sequence;

[0013] Simulate the pouring process based on fluidity simulation software to determine the pouring form;

[0014] Select embedded points according to the physical characteristics of the cast body;

[0015] Select the patch point according to the selected embedded point.

[0016] As a further solution of the present invention: the step of selecting embedded points according to the physical characteristics of the cast body includes:

[0017] The cast molded body is divided according to a preset first grid, and the grid nodes of the first grid are used as internal nodes; the cell length of the first grid is a preset value;

[0018] Get whether there is an entity at the internal node. If there is an entity, set the value of the internal node to one. If there is no entity, set the value of the internal node to zero.

[0019] For any internal node, the eigenvalue at the internal node is calculated based on the preset Gaussian kernel;

[0020] Select the grid nodes whose eigenvalues ​​are greater than the preset eigenvalue threshold as embedded points;

[0021] The step of selecting the patch type point according to the selected embedded point includes:

[0022] Extending the surface of the cast molded body, dividing the cast molded body according to a preset second grid, and using the grid nodes of the second grid as surface nodes;

[0023] For any surface node, calculate the sum of the distances between each internal node and the surface node, and arrange the surface nodes in increasing order of the sum of the distances;

[0024] A preset number of surface nodes are selected from the arranged surface nodes as patch points.

[0025] As a further solution of the present invention, the steps of obtaining prestress based on embedded points, obtaining strain based on patch points, and verifying prestress based on the strain include:

[0026] Obtain prestress based on embedded points at regular intervals, and determine the position tag and time tag according to the position of the embedded points and the acquisition time;

[0027] Acquire strain based on patch points in real time, and determine the position tag and time tag according to the position of the patch points and the acquisition time;

[0028] Verify prestressing based on application in finite element analysis software;

[0029] Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

[0030] As a further solution of the present invention, the steps of counting the verified prestress at each moment, performing spatial domain processing and time domain processing on the prestress, and determining the loss amount include:

[0031] Count the verified prestress at each moment and construct the prestress matrix;

[0032] Calculate the gradient at each data point in the prestress matrix;

[0033] Determine the weight of each data according to the gradient;

[0034] Calculate the loss amount based on the time domain difference of the prestress, accumulate the loss amount according to the weight, and obtain the final loss amount;

[0035] The calculation process of the weight of each data is as follows:

[0036] Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

[0037] As a further solution of the present invention: the step of adjusting the application frequency of the embedded point according to the loss amount determination result includes:

[0038] Read the loss amount calculated at each moment;

[0039] Calculate the rate of change of the loss amount, compare the rate of change of the loss amount with a preset rate of change threshold, query the rate of change threshold reached by the rate of change of the loss amount, and read the application frequency corresponding to the rate of change threshold;

[0040] The corresponding relationship between the change rate threshold and the application frequency is a preset value. The larger the change rate threshold, the higher the application frequency.

[0041] The technical solution of the present invention also provides a prestress loss identification system for a concrete frame structure, the system comprising:

[0042] The point creation module is used to query the concrete frame model, select embedded points within the frame model, and select patch points on the surface of the frame model;

[0043] A stress acquisition and verification module, configured to acquire prestress based on embedded points, acquire strain based on patch points, and verify the prestress based on the strain; wherein the acquired prestress contains a time tag and a position tag, and the acquired strain contains a time tag and a position tag;

[0044] The loss amount determination module is used to count the prestress containing points after verification at each moment, perform spatial domain processing and time domain processing on the prestress, and determine the loss amount;

[0045] The application frequency determination module is used to adjust the application frequency of the embedded point according to the loss amount determination result.

[0046] As a further solution of the present invention: the point creation module includes:

[0047] A benchmark information query unit, used to query the concrete frame model and its pouring sequence;

[0048] A pouring simulation unit is used to simulate the pouring process based on fluidity simulation software and determine the pouring molded body;

[0049] Internal point selection unit, used to select embedded points according to the physical characteristics of the cast body;

[0050] The external point selection unit is used to select the patch point according to the selected embedded point.

[0051] As a further solution of the present invention: the stress acquisition and verification module includes:

[0052] A first data acquisition unit is used to regularly acquire prestress based on the embedded point, and determine a position tag and a time tag according to the position of the embedded point and the acquisition time;

[0053] A second data acquisition unit is used to acquire strain based on the patch point in real time, and determine a position tag and a time tag according to the position of the patch point and the acquisition time;

[0054] Verification execution unit, used to verify prestressing based on application in finite element analysis software;

[0055] Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

[0056] As a further solution of the present invention: the loss amount determination module includes:

[0057] The matrix construction unit is used to count the prestress containing points after verification at each moment and construct the prestress matrix;

[0058] Gradient calculation unit, used to calculate the gradient of each data in the prestress matrix;

[0059] A weight calculation unit, configured to determine the weight of each data according to the gradient;

[0060] a loss amount accumulation unit, configured to calculate the loss amount based on the time domain difference of the prestress, and accumulate the loss amount according to the weight to obtain a final loss amount;

[0061] The calculation process of the weight of each data is as follows:

[0062] Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

[0063] Compared with the prior art, the beneficial effects of the present invention are: the present invention sets embedded points and patch points, obtains prestress by the embedded points, and obtains strain by the patch points, and the strain is used to verify the prestress instead of calculating the prestress, which greatly improves the accuracy of the prestress monitoring results and thus improves the calculation accuracy of the loss amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention.

[0065] Figure 1 Flow chart of the prestress loss identification method for concrete frame structures.

[0066] Figure 2 This is the first sub-process flow chart of the prestress loss identification method for concrete frame structures.

[0067] Figure 3 This is the second sub-process diagram of the prestress loss identification method for concrete frame structures.

[0068] Figure 4 This is the third sub-process diagram of the prestress loss identification method for concrete frame structures.

[0069] Figure 5 This is the fourth sub-process flowchart of the prestress loss identification method for concrete frame structures.

[0070] Figure 6 This is the structural block diagram of the prestress loss identification system for concrete frame structures. DETAILED DESCRIPTION

[0071] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0072] Figure 1 This is a flowchart of a method for identifying prestress loss in a concrete frame structure. In an embodiment of the present invention, a method for identifying prestress loss in a concrete frame structure includes:

[0073] Step S100: querying the concrete frame model, selecting embedded points in the frame model, and selecting patch points on the surface of the frame model;

[0074] Before pouring concrete, a frame model is pre-built. The frame model is the state of the concrete after solidification. Based on the frame model, embedded points and patch points are selected. Among them, fiber optic Bragg grating sensors can be installed at embedded points. Their advantages are resistance to electromagnetic interference, high precision, and suitability for long-term embedded monitoring. Their embedding method is that when the concrete is just poured, it is similar to a fluid and can be completely embedded with fiber optic Bragg grating sensors. Strain gauge sensors can be installed at patch points to monitor the surface strain of concrete or steel bars, and to infer stress or prestress loss through strain. The patch points are easy to install and can be installed directly on the surface.

[0075] Step S200: obtaining prestress based on the embedded points, obtaining strain based on the patch points, and verifying the prestress based on the strain; wherein the obtained prestress contains a time tag and a position tag, and the obtained strain contains a time tag and a position tag;

[0076] Prestress is obtained by fiber optic Bragg grating sensors installed at embedded points, and strain is obtained by strain gauge sensors installed at patch points. The cause of strain is prestress, and the accuracy of prestress monitoring results can be judged based on the strain. At the same time, whether obtaining prestress or strain, time tags and position tags are required.

[0077] Step S300: Counting the prestress at each point after verification, performing spatial and temporal processing on the prestress, and determining the loss amount;

[0078] After the prestress is verified, its accuracy is relatively high. By counting the prestress at each point after verification at different times, identifying the prestress at different points at the same time, and identifying the prestress at the same point at different times, the loss amount can be obtained. The loss amount of prestress refers to the part of the force value that causes the prestress value to decrease due to various reasons after the initial prestress is applied. The main calculation process is the time domain processing process, and the space domain processing process only improves the accuracy of the time domain processing process.

[0079] Step S400: adjusting the application frequency of the embedded points according to the loss amount determination result;

[0080] It should be noted that fiber optic Bragg grating sensors are installed at the embedded points. After installation, it is difficult to remove them. In addition, in order to ensure that the impact is small, no external wiring will be performed (external wiring will increase the volume affected by the concrete pouring process, that is, the volume of the wiring harness contained in the concrete). This means that the energy supply process of the equipment at the embedded points is off-grid. It can only use the equipped power supply, and its energy capacity is limited. In other words, its battery life is limited. Under this architecture, the application frequency of the embedded points is adjusted according to the calculated loss amount to adjust the application frequency and indirectly increase its usage time.

[0081] Figure 2 This is a flowchart of the first sub-process of the method for identifying prestress loss in a concrete frame structure. The steps of querying the concrete frame model, selecting embedded points within the frame model, and selecting patch points on the surface of the frame model include:

[0082] Step S101: querying the concrete frame model and its pouring sequence;

[0083] Step S102: simulating the pouring process based on fluidity simulation software to determine the pouring molded body;

[0084] Step S103: selecting embedded points according to the physical characteristics of the cast body;

[0085] Step S104: Selecting a patch type point according to the selected embedded point.

[0086] In an example of the technical solution of the present invention, the point selection process is described, and the concrete frame model and its pouring sequence are queried. The pouring sequence is generally from which point to start pouring and how much to pour. Then, the pouring process is simulated based on the fluidity simulation software to determine the cast molded body. The fluidity simulation software is mostly existing software, and a simple simulation is sufficient. During the molding process, some missing parts will appear, that is, internal holes, which can be compensated by timed feeding. The timed feeding process is also included in the pouring sequence in the above content. The final cast molded body contains holes, which is used as a simulation result in the simulation software.

[0087] Embedded points are selected based on the entity features of the generated cast molding. After the embedded points are determined, patch points are determined on the surface.

[0088] As a preferred embodiment of the technical solution of the present invention, the step of selecting embedded points according to the physical characteristics of the cast body includes:

[0089] The cast molded body is divided according to a preset first grid, and the grid nodes of the first grid are used as internal nodes; the cell length of the first grid is a preset value;

[0090] Get whether there is an entity at the internal node. If there is an entity, set the value of the internal node to one. If there is no entity, set the value of the internal node to zero.

[0091] For any internal node, the eigenvalue at the internal node is calculated based on the preset Gaussian kernel;

[0092] The grid nodes whose eigenvalues ​​are greater than the preset eigenvalue threshold are selected as embedded points.

[0093] The cast molded body is analyzed and the first grid is inserted into the cast molded body. This can be directly inserted in the software. The grid function is a function available in most software. The cast molded body is divided according to the preset first grid. The grid nodes of the first grid can be called internal nodes. In the cast molded body, it is queried whether there is an entity at the internal node. If so, the value at the internal node is set to one. If no entity exists, the value at the internal node is set to zero. After all internal nodes are assigned values, the eigenvalue of each internal node is calculated. The calculation process uses a Gaussian kernel. It is worth mentioning that since the first grid is regular, each grid node just forms a matrix; in addition, the cell length of the first grid is a preset value, which is used to adjust the number of internal nodes; grid nodes with eigenvalues ​​greater than the preset eigenvalue threshold are selected as embedded points.

[0094] As a preferred embodiment of the technical solution of the present invention, the step of selecting patch-type points based on the selected embedded points includes:

[0095] Extending the surface of the cast molded body, dividing the cast molded body according to a preset second grid, and using the grid nodes of the second grid as surface nodes;

[0096] For any surface node, calculate the sum of the distances between each internal node and the surface node, and arrange the surface nodes in increasing order of the sum of the distances;

[0097] A preset number of surface nodes are selected from the arranged surface nodes as patch points.

[0098] In an example of the technical solution of the present invention, patch-type points are defined, the surface of the cast molded body is extended, the cast molded body is divided according to a preset second grid, and the grid nodes of the second grid are used as surface nodes. This process is actually similar to the process of determining the internal nodes, except that the second grid is a two-dimensional grid for the surface, and the first grid is a three-dimensional grid for the cast molded body; for any surface node, the sum of the distances between each internal node and the surface node is calculated, and the surface nodes are arranged in increasing order of the sum of the distances, and a preset number of surface nodes are selected from the arranged surface nodes as patch-type points.

[0099] Among them, the meaning of arranging the surface nodes according to the increasing order of the sum of the distances is that the surface nodes that are closer to the set internal nodes are closer to the front and are more likely to be selected as patch points, and the verification results of the prestress of the internal nodes are more accurate.

[0100] Figure 3 This is a second sub-flow diagram of the method for identifying prestress loss in a concrete frame structure. The steps of obtaining prestress based on embedded points, obtaining strain based on patch points, and verifying prestress based on the strain include:

[0101] Step S201: acquiring prestress based on embedded points at regular intervals, and determining a position tag and a time tag according to the position of the embedded points and the acquisition time;

[0102] Step S202: acquiring strain based on the patch point in real time, and determining a position tag and a time tag according to the position of the patch point and the acquisition time;

[0103] Step S203: verifying the prestress based on the application in finite element analysis software;

[0104] Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

[0105] In one example of the technical solution of the present invention, prestress containing position tags and time tags is obtained based on embedded points at a scheduled time, and strain containing position tags and time tags is obtained based on patch points in real time. Since the energy amount of the fiber grating sensor installed at the embedded point is limited, its data acquisition and upload frequency should be smaller, that is, data is acquired at a scheduled time; and the patch point is used to install the strain gauge sensor, which can be directly connected to the power supply, and its data acquisition frequency can be higher, so data is acquired in real time.

[0106] After data acquisition is completed, the prestress and strain are aligned according to the time label, and then simulated in the finite element analysis software to verify the prestress.

[0107] Figure 4This is a flowchart of the third sub-process of the method for identifying prestress loss in a concrete frame structure. The steps of counting the verified prestress at each moment, performing spatial and temporal processing on the prestress, and determining the loss amount include:

[0108] Step S301: Counting the prestress of the points after verification at each moment and constructing a prestress matrix;

[0109] Step S302: Calculate the gradient of each data point in the prestress matrix;

[0110] Step S303: Determine the weight of each data according to the gradient;

[0111] Step S304: Calculate the loss amount based on the time domain difference of the prestress, accumulate the loss amount according to the weight, and obtain the final loss amount.

[0112] In an example of the technical solution of the present invention, the calculation process of the loss amount is explained, and the prestress containing points after verification at each moment is counted. Since the points are determined according to the first grid, the nodes of the first grid itself are a matrix structure. The prestress is counted in the order of the points to obtain the prestress matrix. For the prestress matrix at each moment, the gradient of the data at each point is calculated. The gradient includes horizontal gradient and vertical gradient. According to the gradient, the degree of differentiation between the data at each point at that moment and the data at the surrounding points can be determined, and then the weight is determined. Generally, the greater the degree of differentiation, the more important it is considered and the greater the weight.

[0113] After the weight calculation is completed, the time domain difference of the prestress at each point at the current moment is calculated (the difference between the current prestress at the same position and the prestress at the previous moment can be calculated), and then the loss amount is calculated. The loss amount at each position is accumulated based on the weight to obtain the final loss amount. It should be noted that the calculated loss amount is the loss amount at a moment, and the loss amount also contains a time tag. Since the prestress acquisition process is inherently timed and the time interval for obtaining data is large, even if the loss amount at each moment is obtained, the overall loss amount calculation result will not be too much.

[0114] The calculation process of the weight of each data is as follows:

[0115] Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

[0116] The principle of the weight calculation process is that the weight is proportional to the modulus of the sum of the gradients. In addition, the weight must be normalized to the range of zero to one. On the basis of known weights, the final loss can be obtained by multiplying the weight by the loss and then adding them up.

[0117] Figure 5 This is a fourth sub-flow chart of the method for identifying prestress loss in a concrete frame structure, wherein the step of adjusting the application frequency of the embedded points according to the loss amount determination result includes:

[0118] Step S401: reading the loss amount calculated at each moment;

[0119] Step S402: Calculate the loss amount change rate, compare the loss amount change rate with a preset change rate threshold, query the change rate threshold reached by the loss amount change rate, and read the application frequency corresponding to the change rate threshold;

[0120] The corresponding relationship between the change rate threshold and the application frequency is a preset value. The larger the change rate threshold, the higher the application frequency.

[0121] In an example of the technical solution of the present invention, an adjustment process of the application frequency is introduced, the loss amount calculated at each moment is read, and the difference between each loss amount and the loss amount at the previous moment is taken, and then the difference is compared with the current loss amount to obtain the change rate. The change rate of the loss amount is calculated, and the change rate of the loss amount is compared with a preset change rate threshold. The change rate threshold reached by the loss amount change rate is queried, and the application frequency corresponding to the change rate threshold is read; the correspondence between the change rate threshold and the application frequency can be pre-set by the staff in a table, and when in use, the data can be directly read from the table.

[0122] Figure 6 1 is a structural block diagram of a system for identifying prestress loss in a concrete frame structure. In an embodiment of the present invention, a system for identifying prestress loss in a concrete frame structure is provided. The system 10 includes:

[0123] The point creation module 11 is used to query the concrete frame model, select embedded points in the frame model, and select patch points on the surface of the frame model;

[0124] A stress acquisition and verification module 12 is configured to acquire prestress based on embedded points, acquire strain based on patch points, and verify the prestress based on the strain; wherein the acquired prestress includes a time tag and a position tag, and the acquired strain includes a time tag and a position tag;

[0125] The loss amount determination module 13 is used to count the prestressed points after verification at each moment, perform spatial domain processing and time domain processing on the prestressed points, and determine the loss amount;

[0126] The application frequency determination module 14 is used to adjust the application frequency of the embedded points according to the loss amount determination result.

[0127] Furthermore, the point creation module 11 includes:

[0128] A benchmark information query unit, used to query the concrete frame model and its pouring sequence;

[0129] A pouring simulation unit is used to simulate the pouring process based on fluidity simulation software and determine the pouring molded body;

[0130] Internal point selection unit, used to select embedded points according to the physical characteristics of the cast body;

[0131] The external point selection unit is used to select the patch point according to the selected embedded point.

[0132] Specifically, the stress acquisition and verification module 12 includes:

[0133] A first data acquisition unit is used to regularly acquire prestress based on the embedded point, and determine a position tag and a time tag according to the position of the embedded point and the acquisition time;

[0134] A second data acquisition unit is used to acquire strain based on the patch point in real time, and determine a position tag and a time tag according to the position of the patch point and the acquisition time;

[0135] Verification execution unit, used to verify prestressing based on application in finite element analysis software;

[0136] Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

[0137] Furthermore, the loss amount determination module 13 includes:

[0138] The matrix construction unit is used to count the prestress containing points after verification at each moment and construct the prestress matrix;

[0139] Gradient calculation unit, used to calculate the gradient of each data in the prestress matrix;

[0140] A weight calculation unit, configured to determine the weight of each data according to the gradient;

[0141] a loss amount accumulation unit, configured to calculate the loss amount based on the time domain difference of the prestress, and accumulate the loss amount according to the weight to obtain a final loss amount;

[0142] The calculation process of the weight of each data is as follows:

[0143] Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

[0144] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for identifying prestress loss in a concrete frame structure, characterized in that: The method comprises: Query the concrete frame model, select embedded points within the frame model, and select patch points on the surface of the frame model; Acquire prestress based on embedded points, acquire strain based on patch points, and verify prestress based on the strain; wherein the acquired prestress contains a time tag and a position tag, and the acquired strain contains a time tag and a position tag; Count the prestress at each moment after verification, process the prestress in the spatial domain and the time domain to determine the loss amount; Adjust the application frequency of embedded points according to the loss amount determination results; The steps of querying the concrete frame model, selecting embedded points in the frame model, and selecting patch points on the surface of the frame model include: Query the concrete frame model and its pouring sequence; Simulate the pouring process based on fluidity simulation software to determine the pouring form; Select embedded points according to the physical characteristics of the cast body; Select the patch point according to the selected embedded point; The step of selecting embedded points according to the physical characteristics of the cast body comprises: The cast molded body is divided according to a preset first grid, and the grid nodes of the first grid are used as internal nodes; the cell length of the first grid is a preset value; Get whether there is an entity at the internal node. If there is an entity, set the value of the internal node to one. If there is no entity, set the value of the internal node to zero. For any internal node, the eigenvalue at the internal node is calculated based on the preset Gaussian kernel; Select the grid nodes whose eigenvalues ​​are greater than the preset eigenvalue threshold as embedded points; The step of selecting the patch type point according to the selected embedded point includes: Extending the surface of the cast molded body, dividing the cast molded body according to a preset second grid, and using the grid nodes of the second grid as surface nodes; For any surface node, calculate the sum of the distances between each internal node and the surface node, and arrange the surface nodes in increasing order of the sum of the distances; A preset number of surface nodes are selected from the arranged surface nodes as patch points.

2. The method for identifying prestress loss in a concrete frame structure according to claim 1, wherein: The steps of obtaining prestress based on embedded points, obtaining strain based on patch points, and verifying prestress based on the strain include: Obtain prestress based on embedded points at regular intervals, and determine the position tag and time tag according to the position of the embedded points and the acquisition time; Acquire strain based on patch points in real time, and determine the position tag and time tag according to the position of the patch points and the acquisition time; Verify prestressing based on application in finite element analysis software; Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

3. The method for identifying prestress loss in a concrete frame structure according to claim 1, characterized in that: The steps of counting the verified prestress at each moment, performing spatial and temporal processing on the prestress, and determining the loss amount include: Count the verified prestress at each moment and construct the prestress matrix; Calculate the gradient at each data point in the prestress matrix; Determine the weight of each data according to the gradient; Calculate the loss amount based on the time domain difference of the prestress, accumulate the loss amount according to the weight, and obtain the final loss amount; The calculation process of the weight of each data is as follows: Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

4. The method for identifying prestress loss in a concrete frame structure according to claim 1, wherein: The step of adjusting the application frequency of the embedded points according to the loss amount determination result includes: Read the loss amount calculated at each moment; Calculate the rate of change of the loss amount, compare the rate of change of the loss amount with a preset rate of change threshold, query the rate of change threshold reached by the rate of change of the loss amount, and read the application frequency corresponding to the rate of change threshold; The corresponding relationship between the change rate threshold and the application frequency is a preset value. The larger the change rate threshold, the higher the application frequency.

5. A prestress loss identification system for a concrete frame structure, used to execute the prestress loss identification method for a concrete frame structure according to claim 1, characterized in that: The system comprises: The point creation module is used to query the concrete frame model, select embedded points within the frame model, and select patch points on the surface of the frame model; A stress acquisition and verification module, configured to acquire prestress based on embedded points, acquire strain based on patch points, and verify the prestress based on the strain; wherein the acquired prestress contains a time tag and a position tag, and the acquired strain contains a time tag and a position tag; The loss amount determination module is used to count the prestress containing points after verification at each moment, perform spatial domain processing and time domain processing on the prestress, and determine the loss amount; An application frequency determination module, used for adjusting the application frequency of the embedded point according to the loss amount determination result; The point creation module includes: A benchmark information query unit, used to query the concrete frame model and its pouring sequence; A pouring simulation unit is used to simulate the pouring process based on fluidity simulation software and determine the pouring molded body; Internal point selection unit, used to select embedded points according to the physical characteristics of the cast body; The external point selection unit is used to select the patch point according to the selected embedded point.

6. The prestress loss identification system for concrete frame structure according to claim 5, characterized in that: The stress acquisition and verification module includes: A first data acquisition unit is used to regularly acquire prestress based on the embedded point, and determine a position tag and a time tag according to the position of the embedded point and the acquisition time; A second data acquisition unit is used to acquire strain based on the patch point in real time, and determine a position tag and a time tag according to the position of the patch point and the acquisition time; Verification execution unit, used to verify prestressing based on application in finite element analysis software; Among them, when the temperature sensor is installed at the patch point, the strain is compensated and adjusted based on the temperature.

7. The prestress loss identification system for concrete frame structure according to claim 5, characterized in that: The loss amount determination module includes: The matrix construction unit is used to count the prestress containing points after verification at each moment and construct the prestress matrix; Gradient calculation unit, used to calculate the gradient of each data in the prestress matrix; A weight calculation unit, configured to determine the weight of each data according to the gradient; a loss amount accumulation unit, configured to calculate the loss amount based on the time domain difference of the prestress, and accumulate the loss amount according to the weight to obtain a final loss amount; The calculation process of the weight of each data is as follows: Where, For location The weight of the data at For location The data at The gradient in direction, For location The data at The gradient in direction, For location The data at The gradient in direction, for The total number of data in the direction, for The total number of data in the direction, for The total number of data in the direction; direction, Direction and The directions are preset based on the Cartesian coordinate system.

Images