Stress and displacement prediction and working condition judgment method and device, storage medium and equipment

Abstract

The application discloses a stress and displacement prediction and working condition judgment method and device, a storage medium and equipment. The method comprises the following steps: establishing a statics simulation model with a pipe middle arch height according to natural gas suspension cable crossing pipeline basic data; establishing a dynamic response model with the pipe middle arch height according to the statics simulation model; obtaining the pipe displacement initial value of the dynamic response model according to a fitted deformation curve equation; dividing a plurality of load loading positions on the pipe of the dynamic response model according to the movement direction of a pig during a pigging process, and adding corresponding pigging moving loads to the load loading positions; and dynamically solving the dynamic response model to obtain stress prediction values and displacement prediction values of the natural gas suspension cable crossing pipeline at each load loading position when the pig is at each load loading position during the pigging process. The method can predict with higher precision and has good applicability.

Description

Technical Field

[0001] This invention relates to the field of natural gas pipeline safety operation technology, and in particular to a method and apparatus for predicting the stress and displacement during the cleaning of a natural gas cable-stayed pipeline, as well as a computer storage medium and terminal equipment; and a method and apparatus for judging the safe operating conditions during the cleaning of a natural gas cable-stayed pipeline, as well as a computer storage medium and terminal equipment. Background Technology

[0002] Natural gas pipeline suspension crossing structures are complex systems composed of truss bridges that suspend pipelines above deep trenches and canyons. These systems utilize cables, towers, and other components with varying geometries and materials, resulting in significant flexibility and sway tolerance. During construction, the pipeline is typically arched to withstand the structural gravity loads borne by parts of the crossing structure. After completion, the main cable system, main suspenders, main wind cables, wind cable tension cables, conjugate cables, and towers collectively bear the weight of the entire crossing structure, transferring the force to the ground via the piers, thus maintaining the structure in a state of equilibrium. During pipeline cleaning operations, the pipeline vibrates and displaces due to the gravity loads from the cleaning equipment and debris, as well as the impact loads on bends, resulting in complex dynamic behaviors. These vibrations and displacements are caused by the combined effects of gravity, the impact force of the cleaning equipment, and other complex loads.

[0003] Because cable-stayed crossing structures are flexible swaying structures, when the weight or speed of the pigging load exceeds a certain value, the stress or displacement of the pipeline crossing structure will exceed the standard specified values, thereby causing the entire structure to become unstable and increasing the risk of failure. For natural gas pipeline cable-stayed crossing structures, relevant research focuses on the effects of wind loads and seismic loads, with less attention paid to the effects of pigging movement loads. Furthermore, it does not consider the impact of the arching height at the midpoint of the crossing pipeline on the stress and displacement during the pigging process in the actual completed bridge state. Therefore, existing technologies are not accurate enough in predicting the stress and displacement during the pigging process, and it is difficult to make accurate judgments on safe operating conditions. Summary of the Invention

[0004] In order to at least partially solve the above-mentioned technical problems existing in the prior art, the inventors made this invention, which, through specific embodiments, provides a method, apparatus, storage medium, and device for stress and displacement prediction and working condition judgment.

[0005] In a first aspect, embodiments of the present invention provide a method for predicting the stress and displacement during the pigging of a natural gas suspension cable-crossing pipeline, comprising: Based on the foundation data of the natural gas cable-stayed pipeline, a static simulation model was established with the arch height in the middle of the pipeline set. Based on the static simulation model, a dynamic response model was established with the arching height in the middle of the pipe set. Based on the fitted deformation curve equation, the initial value of the pipe displacement of the dynamic response model is obtained; According to the direction of movement of the pig during the pigging process, multiple load loading positions are divided on the pipeline in the dynamic response model, and corresponding pigging movement loads are added to the load loading positions. Based on the initial value of the pipeline displacement and the pigging moving load, the dynamic response model is dynamically solved to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process.

[0006] Optionally, the basic data for the natural gas cable crossing pipeline includes: The length of the pipeline, the pipe material, and the geometric structure of the suspended section of the pipeline; The quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cable, wind cable guy cable, conjugate main cable, and conjugate guy cable in the cable system; The geometric structure, materials, and connection methods between the tower and the cable system; The connection methods between bridge piers and towers, bridge decks, and pipelines; the composition and materials of the bridge deck, and the connection methods between the bridge deck and pipelines, cable systems, towers, and bridge piers; Data on the pipeline's flow rate, pressure, and elevation, as well as the status of pipeline cleaning operations.

[0007] Optionally, the establishment of a static simulation model with a defined arching height in the middle of the pipe includes: The static simulation model is simplified by selecting structural element types, setting constraints and contact conditions, adding prestress to the structure, and setting the arching height in the middle of the pipe, resulting in a static simulation model with the arching height in the middle of the pipe set.

[0008] Optionally, the step of establishing a dynamic response model based on the static simulation model, setting the arching height at the middle of the pipe, includes: Based on the settings in the static simulation model, the static simulation model is converted into the dynamic calculation module, thereby establishing a dynamic response model with the arching height in the middle of the pipe set.

[0009] Optionally, in the step of obtaining the initial value of the pipe displacement of the dynamic response model based on the fitted deformation curve equation, the fitted deformation curve equation includes:

[0010]

[0011] In the formula, u t t represents the displacement at time t; u0 represents the initial displacement of the pipeline from the horizontal axis; t represents the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pipeline pig is denoted by x; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; and g is the acceleration due to gravity.

[0012] Optionally, according to the movement direction of the pig during the pigging process, multiple load loading positions are divided on the pipeline in the dynamic response model, and corresponding pigging movement loads are added at the load loading positions, including: According to the direction of movement of the pig during the pigging process, multiple load steps are sequentially divided on the pipeline in the dynamic response model; The starting position of each load step is used as the load loading position. The static load of the pipeline is applied in the first load step, and the pigging movement load is applied from the second load step to the last load step.

[0013] Optionally, according to the movement direction of the pig during the pigging process, multiple load steps are sequentially divided on the pipeline in the dynamic response model, including: A specific distance is set according to the direction of movement of the pig during the pigging process and the length of the pipe diameter. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached serves as the end point of one load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps sequentially.

[0014] Optionally, the process of applying the pigging movement load from the second load step to the last load step includes: Count the number of load application locations between the second load step and the endpoint coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. ; Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

[0015] Secondly, embodiments of the present invention provide a method for determining the safety conditions of natural gas cable-stayed pipeline pigging, including: Using the aforementioned method, the predicted stress and displacement values ​​of the natural gas suspension cable across the pipeline at each load loading position are obtained during the pipeline cleaning process. Based on the predicted stress and displacement values ​​of the natural gas suspension cable across the pipeline at each load loading position, the predicted maximum stress and maximum displacement values ​​of the pipeline at each load loading position are obtained. The condition in which the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig when the pipeline pig is at the same load loading position is determined as the safe operating condition of the pipeline pig at the load loading position, and then the safe operating condition of the pipeline pig at each load loading position is determined.

[0016] Thirdly, embodiments of the present invention provide a device for predicting the stress and displacement of a natural gas suspension cable crossing pipeline during pigging, comprising: The dynamic response model building module is used to build a static simulation model with the arching height in the middle of the pipeline set according to the basic data of the natural gas cable-stayed pipeline; and to build a dynamic response model with the arching height in the middle of the pipeline set according to the static simulation model. The dynamic response model solving module is used to obtain the initial value of the pipeline displacement of the dynamic response model based on the fitted deformation curve equation; according to the movement direction of the pig during the pigging process, multiple load loading positions are divided on the pipeline of the dynamic response model, and corresponding pigging movement loads are added at the load loading positions; based on the initial value of the pipeline displacement and the pigging movement loads, the dynamic response model is dynamically solved to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process.

[0017] Optionally, the basic data for the natural gas cable crossing pipeline includes: The length of the pipeline, the pipe material, and the geometric structure of the suspended section of the pipeline; The quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cable, wind cable guy cable, conjugate main cable, and conjugate guy cable in the cable system; The geometric structure, materials, and connection methods between the tower and the cable system; The connection methods between bridge piers and towers, bridge decks, and pipelines; the composition and materials of the bridge deck, and the connection methods between the bridge deck and pipelines, cable systems, towers, and bridge piers; Data on the pipeline's flow rate, pressure, and elevation, as well as the status of pipeline cleaning operations.

[0018] Optionally, the dynamic response model building module includes: The static simulation model building module is used to simplify the static simulation model. It allows you to select the structural element type, set constraints and contact conditions, add prestress to the structure, and set the arching height in the middle of the pipe to obtain a static simulation model with the arching height in the middle of the pipe set. The static simulation model conversion module is used to convert the static simulation model into the dynamic calculation module according to the settings in the static simulation model, thereby establishing a dynamic response model with the arching height in the middle of the pipe set.

[0019] Optionally, the dynamic response model solving module includes: The pipeline displacement initial value determination module is used to obtain the pipeline displacement initial value of the dynamic response model based on the following fitted deformation curve equation.

[0020]

[0021] In the formula, u t t represents the displacement at time t; u0 represents the initial displacement of the pipeline from the horizontal axis; t represents the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pipeline pig is denoted by x; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; g is the acceleration due to gravity. The load loading module is used to divide the pipeline in the dynamic response model into multiple load steps according to the movement direction of the pig during the pigging process; the starting position of each load step is used as the load loading position; the static load of the pipeline is loaded in the first load step, and the pigging movement load is loaded from the second load step to the last load step. The dynamic solution module is used to dynamically solve the dynamic response model based on the initial value of the pipeline displacement and the pigging moving load, so as to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each of the load loading positions during the pigging process.

[0022] Optionally, the load loading module includes: The load step division module is used to set a specific distance based on the pipe diameter, according to the direction of movement of the pig during the pigging process. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached is used as the end point of a load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps in sequence; The static load loading module is used to set the starting position of each load step as the load loading position and load the static load on the pipeline in the first load step. The pigging movement load loading module is used to count the number of load loading positions between the second load step and the end coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

[0023] Fourthly, embodiments of the present invention provide a device for determining the safety conditions of natural gas cable-stayed pipeline pigging, comprising: The stress and displacement maximum value prediction module is used to obtain, using the aforementioned method, the predicted stress and displacement values ​​of the natural gas cable crossing the pipeline at each load loading position of the pipeline pig during the pipeline pigging process; and based on the predicted stress and displacement values ​​of the natural gas cable crossing the pipeline at each load loading position of the pipeline pig, to obtain the predicted maximum stress and maximum displacement values ​​of the pipeline at each load loading position of the pipeline pig. The safety condition judgment module is used to determine the condition in which the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig at the same load loading position as the safe operating condition of the pipeline pig at the load loading position, and then to determine the safe operating condition of the pipeline pig at each load loading position.

[0024] Based on the same inventive concept, this embodiment of the invention provides a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for predicting the stress and displacement of natural gas suspension crossing pipelines.

[0025] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing computer-executable instructions, which, when executed, realize the aforementioned method for predicting stress and displacement during the cleaning of natural gas suspension crossing pipelines.

[0026] Based on the same inventive concept, this embodiment of the invention provides a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for determining the safe working conditions of natural gas suspension crossing pipeline cleaning.

[0027] Based on the same inventive concept, this embodiment of the invention also provides a computer storage medium storing computer-executable instructions, which, when executed, implement the aforementioned method for determining the safe operating conditions of natural gas suspension crossing pipeline cleaning.

[0028] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following: This invention provides a method, apparatus, storage medium, and equipment for predicting the stress and displacement during the pigging of a natural gas suspension bridge crossing pipeline. It considers the influence of the arching height in the middle of the suspension bridge under actual completed bridge conditions. The deviation between the calculated prestress of the cable system in the static analysis model and the measured values ​​on site is small, which helps to provide more accurate parameters for the dynamic response model. The predicted maximum stress value deviates less from the actual maximum stress value under completed bridge conditions. The fitted deformation curve equation prediction results have a high correlation with the experimental test values, and the maximum displacement value deviation is small, resulting in higher prediction accuracy. The number of load loading positions on the pipeline can be adjusted as needed. By appropriately reducing the number of load loading positions, the computational load can be reduced and the prediction efficiency improved; or by increasing the number of load loading positions, more accurate and detailed prediction values ​​can be obtained. Therefore, this solution has good applicability.

[0029] This invention provides a method, apparatus, storage medium, and equipment for determining the safety conditions of a natural gas suspension bridge crossing pipeline. It considers the influence of the arching height in the middle of the natural gas pipeline under actual bridge conditions. The deviation between the calculated prestress of the cable system in the static analysis model and the measured values ​​on site is small, which helps to provide more accurate parameters for the dynamic response model. The predicted maximum stress value deviates less from the actual maximum stress value under bridge conditions. The fitted deformation curve equation prediction results have a high correlation with the experimental test values, and the maximum displacement value deviation is small, resulting in higher prediction accuracy and more accurate judgment of the safety conditions. The number of load loading positions on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the computational load can be reduced, prediction efficiency improved, and the speed of safety condition judgment increased. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained, determining the safety conditions at more locations. Therefore, this solution has good applicability.

[0030] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a method for predicting the stress and displacement during the cleaning of a natural gas cable-stayed pipeline, as described in an embodiment of the present invention. Figure 2 This is a diagram showing the load application for pigging at time t=39 s in an embodiment of the present invention. Figure 3 This is a flowchart of a method for determining the safety conditions of pipeline cleaning for natural gas cable-stayed crossings, as described in an embodiment of the present invention. Figure 4 This is a schematic diagram illustrating the maximum predicted vertical displacement of the pipeline at time t=39 s in an embodiment of the present invention. Figure 5 This is a schematic diagram illustrating the maximum predicted value of pipeline stress at time t=39 s in an embodiment of the present invention. Figure 6 This is a block diagram of a natural gas suspension crossing pipeline cleaning stress and displacement prediction device according to an embodiment of the present invention; Figure 7This is a block diagram of a natural gas suspension crossing pipeline cleaning safety condition judgment device according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a terminal device according to an embodiment of the present invention. Detailed Implementation

[0033] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0034] To address the problems existing in the prior art, embodiments of the present invention provide a method, apparatus, storage medium, and device for stress and displacement prediction and working condition judgment.

[0035] Example 1 Embodiment 1 of the present invention provides a method for predicting the stress and displacement during the pigging of natural gas cable-stayed pipelines, the process of which is as follows: Figure 1 As shown, it includes the following steps: Step S101: Based on the foundation data of the natural gas suspension cable crossing pipeline, a static simulation model with the arch height in the middle of the pipeline set is established.

[0036] Optionally, the basic data for the natural gas cable-stayed pipeline crossing includes: the pipeline length, pipe material, and geometric structure of the suspended section; the quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cables, wind cable pull cables, conjugate main cables, and conjugate pull cables in the cable system; the geometric structure, material, and connection method of the tower to the cable system; the connection method between the piers and the tower, bridge deck, and pipeline; the configuration, material, and connection method between the bridge deck and the pipeline, cable system, tower, and piers; the throughput, pressure, and elevation data of the pipeline, as well as the pipeline cleaning operation status.

[0037] Optionally, the establishment of a static simulation model with a defined arching height in the middle of the pipe includes: The static simulation model is simplified by selecting structural element types, setting constraints and contact conditions, adding prestress to the structure, and setting the arching height in the middle of the pipe, resulting in a static simulation model with the arching height in the middle of the pipe set.

[0038] Step S102: Based on the static simulation model, a dynamic response model is established with the arching height in the middle of the pipe set.

[0039] Optionally, based on the settings in the static simulation model, the static simulation model can be converted into a dynamic calculation module to establish a dynamic response model with the arching height in the middle of the pipe set.

[0040] Step S103: Obtain the initial value of the pipe displacement of the dynamic response model based on the fitted deformation curve equation.

[0041] Optionally, in the step of obtaining the initial value of the pipe displacement of the dynamic response model based on the fitted deformation curve equation, the fitted deformation curve equation includes:

[0042]

[0043] In the formula, u t t represents the displacement at time t; u0 represents the initial displacement of the pipeline from the horizontal axis; t represents the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pipeline pig is denoted by x; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; and g is the acceleration due to gravity.

[0044] Step S104: According to the movement direction of the pig during the pigging process, divide the pipeline in the dynamic response model into multiple load loading positions, and add the corresponding pigging movement load at the load loading positions.

[0045] Optionally, according to the direction of movement of the pig during the pigging process, multiple load steps are sequentially divided on the pipeline in the dynamic response model; the starting position of each load step is taken as the load loading position. The static load of the pipeline is loaded in the first load step, and the pigging movement load is loaded from the second load step to the last load step. Among them, the static load that crosses the structure, i.e., the gravity load, is loaded in the first load step of the dynamic response model.

[0046] Optionally, a specific distance can be set according to the direction of movement of the pig during the pigging process and the length of the pipe diameter. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached serves as the end point of one load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps sequentially.

[0047] Optionally, count the number of load application locations between the second load step and the endpoint coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

[0048] Step S105: Based on the initial value of the pipeline displacement and the pigging moving load, the dynamic response model is dynamically solved to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process.

[0049] For example, a large natural gas pipeline suspension bridge has a total length of 545.6 meters, a main span of 360 meters, a south anchor span of 109.9 meters, and a north anchor span of 75.7 meters. The main cable's span-to-span ratio is 1 / 10, the wind cable's span-to-span ratio is 1 / 15, and the conjugate cable's span-to-span ratio is 1 / 42. The main cable type is PESC5-283, the main suspension cable type is PESH5-13, the wind cable's main cable type is PESC5-151, the wind cable's tension cable type is PESH5-7, the conjugate main cable type is PESC5-71, and the conjugate tension cable type is PESH5-7. The south bank pipeline's underground section uses two hot-bent bends, with temperature compensation achieved through risers; both bends are 90°. The bridge deck is a steel truss, and a natural gas pipeline is laid there, using Φ610×11.9 mm X65 M straight seam submerged arc welded steel pipe. The main cable and wind cables share anchorage piers on the south side. Lateral wind cable supports are installed at the south bank tower, while two separate wind cable anchorage piers are installed on the north bank. Two conjugate cables are installed beneath the bridge deck. There is one 40.73-meter bridge tower on each bank, with the tower base connected to the pier cap via a hinged connection. The tower has a rectangular cross-section lattice structure. The main members and transverse diaphragms are made of Φ325 and Q345C seamless steel pipes, while other connecting members such as diagonal web members are made of Q345C steel. The web members have a "K" shaped structure. Suspension cables, wind cables, and conjugate cables are installed at 5-meter intervals along the pipe bridge direction. The arch height at the half-span of the completed bridge is 1.86 meters.

[0050] Based on the commercial simulation software ANSYS Workbench 18.1, the dynamic response of the above-mentioned natural gas pipeline suspension crossing structure during the cleaning process was analyzed, and the stress and displacement of the pipeline were calculated.

[0051] Collect basic data on the cable-stayed bridge structure of the natural gas pipeline. Based on the design data, on-site construction data, and daily operation data of the cable-stayed bridge natural gas pipeline, collect basic data on the cable-stayed bridge natural gas pipeline, including but not limited to: pipeline length, pipe material, and geometric structure of the suspended section of the pipeline; the quantity, material, spatial composition, and interconnection method of the main cable, suspenders, wind cable main cables, wind cable tension cables, conjugate main cables, and conjugate tension cables in the cable system; the geometric structure and material of the tower and the connection method between the tower and the cable system; the connection method between the piers and the tower, bridge deck, and pipeline; the composition and material of the bridge deck and the connection method between the bridge deck and the pipeline, cable system, tower, and piers; the throughput, pressure, and elevation data of the pipeline, as well as the pipeline cleaning operation status.

[0052] A static simulation model was established, with the arch height set at the middle of the pipeline, and conforming to the geometry and structural stress of the suspension bridge spanning the natural gas pipeline in its actual completed state. This model includes: (1) Simplification of the simulation model: The tower fixed pier, anchoring system and wind cable lateral support are used as the stability constraints of the cable system; the riveted components in the crossing structure, such as tower and cable, bridge deck and pipe support, cable and anchor pier, are simulated with the same constraint conditions; circular steel wire rope with the same cross-sectional area is used to replace the composite steel cable with a protective layer made of multiple strands of steel wire rope in the actual crossing structure.

[0053] (2) Use of structural element types in simulation software: Since the axial length of the natural gas pipeline in the spanning structure is much larger than its cross-sectional diameter, the pipeline is treated as a Timoshinko beam (a Timoshinko beam is a beam that can take into account shear deformation. Specifically, its displacement and cross-sectional rotation are independently interpolated, rather than obtained by the derivative of the displacement); Since the axial dimension of the cable system is much larger than the cross-sectional dimension, and it can only bear tension but not compression, it is necessary to select cable elements with functions such as stress stiffening, large deformation, and large strain; The tower, bridge deck, and pipeline support are all modeled as solid models, and the steel density is adjusted according to the actual weight of the spanning structure to obtain the same mass per unit length as the structure.

[0054] The piping elements are Solid 186; Link 180 is selected as the cable element for the model; the towers, bridge decks, and pipe supports all use Solid 186 elements. Solid 186, Link 180, and the Bond contact, Noseperation contact, and Revolute mentioned below are all settings provided by ANSYS Workbench.

[0055] (3) Constraint and contact condition settings: The anchorage structure is fully constrained in six degrees of freedom. Because the displacement of the hinged support at the bottom of the tower is very small in the actual completed bridge state, the connection between the tower and the fixed pier is a fixed connection without relative movement. Fixed contact is used between the cable and the bridge deck, the main cable and the tower, and the bridge deck and the fixed pier. The cable system is set as a common node with rotational displacement but no translational displacement. The bridge deck and the pipe are connected by a support and a pipe clamp, so the contact between the pipe and the pipe clamp is set as a contact form that can have slight axial sliding. The cable system and the bridge deck use Bond contact; the main cable and the tower use Bond contact; the cable system uses a common node contact; the rolling support and the pipe use No Seperation contact; the bridge deck and the abutment use Bond contact; the tower and the pier use Revolute, and the tower is set to have a degree of freedom of rotation relative to the pier.

[0056] (4) Prestressing, cable system form finding, and setting the arch height in the middle of the pipeline: Strain, as the ratio of deformation to initial size, is usually small in magnitude. It can only be used to add prestress to the cable tentatively, and then judge whether the prestress is appropriate by the stress and displacement of the model obtained after solving. For the crossing pipeline with a certain arch height in the middle, it is also necessary to gradually adjust the prestress value in the cable system so that the difference between the arch displacement and the actual displacement meets the accuracy requirements. The large displacement stiffness matrix is ​​introduced into the model solution by setting the large deformation effect (NIGEOM); the initial strain is added to the cable, which is achieved by the initialization statement "INISTATE" in the command flow; cables with the same initial strain value are selected as a group, a name group is created, and the corresponding name is selected and the initial strain is assigned to all elements in it when the model is loaded; with the mid-span displacement of 1.86 meters as the target, a reasonable cable system prestress value is searched until the calculated vertical arch displacement of the model is about 1.86 m. The initial state parameters of the static model of the natural gas pipeline suspension crossing structure are shown in Table 1.

[0057] Table 1 Initial state parameters of the static model of the natural gas pipeline cable-stayed structure

[0058] Based on the settings in the static simulation model, the established static model is imported into the dynamic calculation module of the mechanics simulation software ANSYS Workbench, thereby establishing a dynamic response model with the arching height in the middle of the pipeline set. The selection of component elements for the suspension cable crossing the natural gas pipeline, the connection methods between components, and the constraints and contact conditions are directly adopted from the established static model.

[0059] The initial values ​​of the pipe displacement for the dynamic response model are obtained based on the fitted deformation curve equation.

[0060]

[0061] In the formula, u t t represents the displacement at time t; u0 represents the initial displacement of the pipeline from the horizontal axis; t represents the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pipeline pig is denoted by x; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; and g is the acceleration due to gravity.

[0062] Based on the direction of movement of the pig during the pigging process, a distance of 20 times the pipe diameter is taken as the specific distance. Each time the pig runs The distance, as a load step, is the distance the pig travels from its starting point to the destination. The distance reached serves as the end point of one load step and the start point of the next load step.

[0063] To simulate the static equilibrium state of the cable-stayed natural gas pipeline before applying moving loads, the first load step of the model requires applying a static load to the spanning structure and adding initial strain values ​​obtained from cable form-finding analysis to the cables. The state at the end of the first load step is used as the initial state to begin subsequent dynamic response analysis. Specifically, the first load step of the dynamic response model applies a static load (gravity load) to the spanning structure and adds initial strain values ​​obtained from cable form-finding analysis to the cables, using the state at the end of the first load step as the initial state. The calculated values ​​from the deformation curve equation are used as the initial values ​​for subsequent iterations at different times, accelerating the software's efficiency and computational convergence speed.

[0064] Assuming the entire spanning structure is subjected to pigging loads n times, plus the initial load step set in the initial state, the number of load steps in the dynamic response model is... It should be: (1) (2) (3) In the formula, N step This represents the total load steps in the dynamic response model; n This represents the total number of times the cleaning load is collected; L P It is the total span length of the structure;L k This refers to the pig's travel distance when determining the pig load. D It is the outer diameter of the pipe.

[0065] The operation of applying the pigging moving load from the second load step to the last load step is as follows: (1) Acquisition and processing of coordinate parameters of the inner surface of the pipe. First, when establishing the geometric model, the node coordinate values ​​of the inner surface of the pipe are created and a coordinate table is formed; then, based on the coordinate axis of the pipe axis, the coordinate parameters of the inner surface of the pipe are sorted in ascending order according to the flow direction of the fluid. The resulting coordinate parameter table will be the basis for compiling various load data in the future.

[0066] (2) Gravity load data compilation. Compiling gravity load data requires tracking and locating the pig and debris. Taking the pig's movement along the positive x-axis as an example, assume the coordinates of the pipeline's starting point are... At time t, the distance between the starting point of the pig and the starting point of the pipeline is calculated. pig length and length of dirt It can locate and load gravity loads, and the specific steps are as follows: 1) Calculate the starting point coordinates of the pig, the ending point coordinates of the pig, and the ending point coordinates of the pig debris:

[0067]

[0068]

[0069] In the formula, These are the coordinates of the starting point of the pig. The endpoint coordinates of the pig; The coordinates of the endpoint of the sewage cleaning process; These are the coordinates of the pipeline's starting point; This is the distance between the starting point of the pig and the starting point of the pipeline; This refers to the length of the pig. The length of the sewage in the pipe is used for cleaning.

[0070] 2) According to , and Key points are located in the coordinate parameter table of the loading points on the inner surface of the pipe, subject to the mesh generation scale. Due to the influence of the calculated values, there may be a discrepancy between the actual key point locations and the calculated values. The deviation is within a certain range; therefore, the coordinates of the key points obtained from the positioning are represented as follows: , and ; 3) Statistics ~ Number of all load points between ,as well as ~ Number of all load points between The gravitational force acting on each loading point is calculated as a uniformly distributed load:

[0071]

[0072] In the formula, for ~ The gravity load value that should be applied at the loading points between them; For the gravity load of the pipeline pig; for ~ The gravity load value that should be applied to all loading points in between; For the gravity load of sewage during pipe cleaning; for ~ The total number of all loading points in between; for ~ The total number of loading points in between; the subscript I indicates the number of the loading point.

[0073] 4) Create a new column in the sorted and organized loading point coordinate parameter table, and direct it to... ~ Add to the table corresponding to the loading point between them Value, towards ~ Add to the table corresponding to the loading point between them value.

[0074] The dynamic response calculation model for the suspension bridge crossing natural gas pipeline cleaning process was solved using ANSYS Workbench software. The Newmark time integration method was selected for model solving; the time step was taken as 1 / 5 to 1 / 6 of the minimum natural period of the structure. The Reyleigh damping model was used to calculate the system damping, with the contact damping ratio between the steel members taken as 0.02; the time step was... The value should be 0.06~0.1 seconds; the values ​​of the integration parameters γ and β should be 0.5 and 0.25, respectively.

[0075] Using the External Data module in ANSYS Workbench software, load, displacement, and wall thickness data can be imported in batches by using coordinate position and node number. Furthermore, the loading position of the pigging load will continuously change along the pipeline axis, and the calculation result of the pigging load is also related to the pipeline axial coordinate.

[0076] After setting the relevant parameters in the ANSYS Workbench software, dynamic solutions can be automatically performed. Taking the natural gas pipeline suspension bridge structure in this example as divided into 30 equal parts, with the distance between each node being 1 / 30 of the span (12 meters), then (30-1) nodes need to be selected. The displacement prediction values ​​at each node are exported and listed in Table 2. After processing using Excel software, the iteration termination conditions are checked. If the conditions are met, the solution ends, and this iteration is the solution of the dynamic response model; otherwise, the displacement correction value for this iteration is calculated and substituted into the calculation of the pigging load to enter the next iterative calculation.

[0077] Table 2 Dynamic Response Displacement Prediction Table

[0078] Taking a pigging speed of 3.58 m / s, a pigging load weight of 35060 kg, and a total pigging load length of 56.48 m as an example. (Refer to...) Figure 2 The diagram showing the pigging load at time t=39 s indicates that the two ends of the pipe are S-shaped and Z-shaped, respectively, and the cross-structure pipes beyond the two ends are close to the horizontal lines. The markings indicate the loading locations of the pigging movement loads on the cable-stayed bridge structure of the natural gas pipeline. It's an arrow pointing in the direction of gravity. The horizontal direction to the right is the positive direction of the X-axis, the vertical direction downwards is the positive direction of the Z-axis, and the Y-axis is perpendicular to the surface of the graph. Below... This is the image scale.

[0079] After testing, considering the influence of the 1.86-meter arch height in the middle of the suspension bridge crossing the natural gas pipeline under actual completed bridge conditions, the deviation between the prestress calculation results of the cable system in the established static analysis model and the field measured values ​​is less than 4%; the correlation between the predicted results of the fitted deformation curve equation and the experimental test values ​​is greater than 0.94; the deviation between the calculated maximum stress value and the maximum stress value under actual completed bridge conditions is less than 4%, and the deviation between the maximum displacement value and the maximum displacement value is less than 15%. Therefore, it can be proved that the established pipeline cleaning dynamic response model can be used for stress and displacement calculation during the pipeline cleaning process of the suspension bridge crossing the natural gas pipeline.

[0080] In the above method of this embodiment, the influence of the arching height of the suspension cable crossing the natural gas pipeline in the actual completed bridge state is considered. The deviation between the prestress calculation results of the cable system in the static analysis model and the field measured values ​​is small, which helps to provide more accurate parameters for the dynamic response model. The maximum stress prediction value deviates less from the maximum stress value in the actual completed bridge state. The fitting deformation curve equation prediction results have a high correlation with the experimental test values. The maximum displacement value deviation is small, and the prediction accuracy is higher. The number of load loading positions divided on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the amount of calculation can be reduced and the prediction efficiency can be improved. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained. Therefore, this scheme has good applicability.

[0081] Example 2 Embodiment 2 of the present invention provides a method for determining the safety conditions of natural gas cable-stayed pipeline pigging, the process of which is as follows: Figure 3 As shown, it includes the following steps: Step S201: Using the aforementioned method for predicting the stress and displacement of the natural gas cable-stayed pipeline during the cleaning process, the predicted stress and displacement values ​​of the natural gas cable-stayed pipeline at each load loading position of the pipeline cleaning device are obtained. Step S202: Based on the predicted stress and displacement values ​​of the natural gas suspension cable across the pipeline at each load loading position, the predicted maximum stress and maximum displacement values ​​of the pipeline at each load loading position are obtained. Step S203: Determine the operating condition where the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig's displacement when the pipeline pig is at the load loading position as the safe operating condition of the pipeline pig at the load loading position, and then determine the safe operating condition of the pipeline pig at each load loading position.

[0082] For example, following the method in Example 1, after setting the relevant parameters in the ANSYS Workbench software, dynamic solving can be performed automatically to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing pipeline at each load loading position during the pipeline cleaning process. Taking the natural gas pipeline suspension cable crossing structure in this example as divided into 30 equal parts, with the distance between each node being 1 / 30 of the span length, i.e., 12 meters, then (30-1) nodes need to be selected, and the predicted displacement values ​​at each node are exported to form Table 2. After processing using Excel software, the iteration termination condition is checked. If the condition is met, the solution ends, and this iteration is the solution of the dynamic response model; otherwise, the displacement correction value of this iteration is calculated and substituted into the calculation of the cleaning load to enter the next cycle iteration calculation.

[0083] From the above displacement prediction values, find the maximum predicted displacement of the pipeline when the pig is at the load loading position. Alternatively, a dynamic response stress prediction table can be compiled, and the maximum predicted stress of the pipeline when the pig is at the load loading position can be found from the stress prediction values ​​in the table. Further, the maximum predicted stress and maximum predicted displacement of the pipeline at each load loading position are obtained.

[0084] Among them, the maximum predicted values ​​of pipe displacement and stress when the time is equal to 39 seconds are respectively referred to Figure 4 and Figure 5 As shown. The calculated results of the vertical displacement across the pipe at time t=39 seconds are as follows. Figure 4 As shown in the figure The marked locations indicate the positions of the maximum predicted vertical displacement of the pipeline. The marked locations indicate the minimum predicted vertical displacement of the pipeline. The left side shows the displacement scale, with different colors corresponding to different displacement values ​​in mm. The displacement prediction results from the model show that the maximum predicted displacement of the pipeline crossing 39 seconds into the cleaning process is 1804.3 mm.

[0085] The stress calculation results across the pipe at time t=39 seconds are as follows: Figure 5 As shown in the figure The marked locations are the predicted locations of the maximum pipe stress. The marked locations indicate the minimum predicted values ​​of pipeline stress. The left side shows a stress scale, with different colors corresponding to different stress values ​​in MPa. From the stress prediction results obtained from the model, the maximum predicted stress value for the pipeline crossing 39 seconds into the cleaning process is 188.76 MPa.

[0086] Therefore, when time t=39 seconds, it can be determined that the working condition in which the pipeline displacement does not exceed 1804.3 mm and the pipeline stress does not exceed 188.76 MPa is a safe working condition, and the working condition in which one or all of the above values ​​are exceeded is an unsafe working condition.

[0087] In this embodiment, the influence of the arching height of the suspension cable crossing the natural gas pipeline in the actual completed bridge condition is considered. The deviation between the prestress calculation results of the cable system in the static analysis model and the field measured values ​​is small, which helps to provide more accurate parameters for the dynamic response model. The maximum stress prediction value deviates less from the maximum stress value in the actual completed bridge condition. The fitting deformation curve equation prediction results have a high correlation with the experimental test values. The maximum displacement value deviation is small, the prediction accuracy is higher, and the judgment of safe working conditions is more accurate. The number of load loading positions on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the amount of calculation can be reduced, the prediction efficiency can be improved, and the speed of judging safe working conditions can be increased. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained, and the safe working conditions of more positions can be determined. Therefore, this scheme has good applicability.

[0088] Example 3 Embodiment 3 of the present invention provides a device for predicting the stress and displacement of natural gas suspension crossing pipeline during pigging, the structure of which is as follows: Figure 6 As shown, it includes: The dynamic response model establishment module 101 is used to establish a static simulation model with the arching height in the middle of the pipeline set according to the basic data of the natural gas suspension crossing pipeline; and to establish a dynamic response model with the arching height in the middle of the pipeline set according to the static simulation model. The dynamic response model solving module 102 is used to obtain the initial value of the pipeline displacement of the dynamic response model based on the fitted deformation curve equation; according to the movement direction of the pig during the pigging process, it divides the pipeline of the dynamic response model into multiple load loading positions, and adds corresponding pigging movement loads at the load loading positions; based on the initial value of the pipeline displacement and the pigging movement loads, it dynamically solves the dynamic response model to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process.

[0089] Optionally, the basic data for the natural gas cable crossing pipeline includes: The length of the pipeline, the pipe material, and the geometric structure of the suspended section of the pipeline; The quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cable, wind cable guy cable, conjugate main cable, and conjugate guy cable in the cable system; The geometric structure, materials, and connection methods between the tower and the cable system; The connection methods between bridge piers and towers, bridge decks, and pipelines; the composition and materials of the bridge deck, and the connection methods between the bridge deck and pipelines, cable systems, towers, and bridge piers; Data on the pipeline's flow rate, pressure, and elevation, as well as the status of pipeline cleaning operations.

[0090] Optionally, the dynamic response model establishment module 101 includes: The static simulation model building module is used to simplify the static simulation model. It allows you to select the structural element type, set constraints and contact conditions, add prestress to the structure, and set the arching height in the middle of the pipe to obtain a static simulation model with the arching height in the middle of the pipe set. The static simulation model conversion module is used to convert the static simulation model into the dynamic calculation module according to the settings in the static simulation model, thereby establishing a dynamic response model with the arching height in the middle of the pipe set.

[0091] Optionally, the dynamic response model solving module 102 includes: The pipeline displacement initial value determination module is used to obtain the pipeline displacement initial value of the dynamic response model based on the following fitted deformation curve equation.

[0092]

[0093] In the formula, u t t represents the displacement at time t; u0 represents the initial displacement of the pipeline from the horizontal axis; t represents the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pipeline pig is denoted by x; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; g is the acceleration due to gravity. The load loading module is used to divide the pipeline in the dynamic response model into multiple load steps according to the movement direction of the pig during the pigging process; the starting position of each load step is used as the load loading position; the static load of the pipeline is loaded in the first load step, and the pigging movement load is loaded from the second load step to the last load step. The dynamic solution module is used to dynamically solve the dynamic response model based on the initial value of the pipeline displacement and the pigging moving load, so as to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each of the load loading positions during the pigging process.

[0094] Optionally, the load loading module includes: The load step division module is used to set a specific distance based on the pipe diameter, according to the direction of movement of the pig during the pigging process. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached is used as the end point of a load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps in sequence; The static load loading module is used to set the starting position of each load step as the load loading position and load the static load on the pipeline in the first load step. The pigging movement load loading module is used to count the number of load loading positions between the second load step and the end coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

[0095] In the above method of this embodiment, the influence of the arching height of the suspension cable crossing the natural gas pipeline in the actual completed bridge state is considered. The deviation between the prestress calculation results of the cable system in the static analysis model and the field measured values ​​is small, which helps to provide more accurate parameters for the dynamic response model. The maximum stress prediction value deviates less from the maximum stress value in the actual completed bridge state. The fitting deformation curve equation prediction results have a high correlation with the experimental test values. The maximum displacement value deviation is small, and the prediction accuracy is higher. The number of load loading positions divided on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the amount of calculation can be reduced and the prediction efficiency can be improved. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained. Therefore, this scheme has good applicability.

[0096] Example 4 Embodiment 4 of the present invention provides a safety condition judgment device for natural gas cable-stayed pipeline pigging, the structure of which is as follows: Figure 7 As shown, it includes: The stress and displacement maximum value prediction module 201 is used to obtain the stress prediction value and displacement prediction value of the natural gas suspension cable crossing pipeline at each load loading position of the pipeline during the pipeline cleaning process using the aforementioned natural gas suspension cable crossing pipeline cleaning stress and displacement prediction method; and to obtain the maximum stress prediction value and maximum displacement prediction value of the pipeline at each load loading position of the pipeline using the pipeline cleaning tool based on the stress prediction value and displacement prediction value of the natural gas suspension cable crossing pipeline at each load loading position of the pipeline cleaning tool. The safety condition judgment module 202 is used to determine the condition in which the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig when the same load loading position is the safe operating condition of the pipeline pig at the load loading position, and then determine the safe operating condition of the pipeline pig at each load loading position.

[0097] In this embodiment, the influence of the arching height of the suspension cable crossing the natural gas pipeline in the actual completed bridge condition is considered. The deviation between the prestress calculation results of the cable system in the static analysis model and the field measured values ​​is small, which helps to provide more accurate parameters for the dynamic response model. The maximum stress prediction value deviates less from the maximum stress value in the actual completed bridge condition. The fitting deformation curve equation prediction results have a high correlation with the experimental test values. The maximum displacement value deviation is small, the prediction accuracy is higher, and the judgment of safe working conditions is more accurate. The number of load loading positions on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the amount of calculation can be reduced, the prediction efficiency can be improved, and the speed of judging safe working conditions can be increased. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained, and the safe working conditions of more positions can be determined. Therefore, this scheme has good applicability.

[0098] Based on the same inventive concept, embodiments of the present invention also provide a terminal device, the structure of which is as follows: Figure 8 As shown, it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for predicting the stress and displacement of natural gas cable-stayed pipelines during cleaning.

[0099] Based on the same inventive concept, this embodiment of the invention also provides a computer storage medium, comprising: computer executable instructions stored in the computer storage medium, wherein the computer executable instructions, when executed, implement the aforementioned method for predicting the stress and displacement of natural gas suspension crossing pipelines.

[0100] Based on the same inventive concept, embodiments of the present invention also provide a terminal device, the structure of which is as follows: Figure 8As shown, it includes: a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, it implements the aforementioned method for determining the safety conditions of pipeline cleaning for natural gas suspension crossings.

[0101] Based on the same inventive concept, this embodiment of the invention also provides a computer storage medium, including: computer executable instructions stored in the computer storage medium, wherein the computer executable instructions, when executed, implement the aforementioned method for determining the safe working condition of natural gas suspension crossing pipeline cleaning.

[0102] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0103] The method and apparatus described in this invention take into account the influence of the arching height of the suspension cable crossing the natural gas pipeline in the actual completed bridge condition. The deviation between the prestress calculation results of the cable system in the static analysis model and the measured values ​​on site is small, which helps to provide more accurate parameters for the dynamic response model. The maximum stress prediction value deviates less from the maximum stress value in the actual completed bridge condition. The fitting deformation curve equation prediction results have a high correlation with the experimental test values. The maximum displacement value deviation is small, the prediction accuracy is higher, and the judgment of safe working conditions is more accurate. The number of load loading positions on the pipeline can be adjusted as needed. By appropriately reducing the load loading positions, the amount of calculation can be reduced, the prediction efficiency can be improved, and the speed of judging safe working conditions can be increased. Alternatively, by increasing the load loading positions, more accurate and detailed prediction values ​​can be obtained, and the safe working conditions of more positions can be determined. Therefore, this solution has good applicability.

Claims

1. A method for predicting the stress and displacement during pigging of a natural gas suspension cable-crossing pipeline, characterized in that, include: Based on the foundation data of the natural gas cable-stayed pipeline, a static simulation model was established with the arch height in the middle of the pipeline set. Based on the static simulation model, a dynamic response model was established with the arching height in the middle of the pipe set. Based on the fitted deformation curve equation, the initial value of the pipe displacement of the dynamic response model is obtained; In the step of obtaining the initial value of the pipe displacement of the dynamic response model based on the fitted deformation curve equation, the fitted deformation curve equation includes: In the formula, u t Let u0 be the displacement at time t; u0 is the initial displacement of the pipeline from the horizontal axis; and t is the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pig is denoted by 'x'; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; g is the acceleration due to gravity. According to the direction of movement of the pig during the pigging process, multiple load loading positions are divided on the pipeline in the dynamic response model, and corresponding pigging movement loads are added to the load loading positions. According to the movement direction of the pig during the pigging process, multiple load loading positions are divided on the pipeline in the dynamic response model, and corresponding pigging movement loads are added to the load loading positions, including: According to the direction of movement of the pig during the pigging process, multiple load steps are sequentially divided on the pipeline in the dynamic response model; The starting position of each load step is taken as the load application position. The static load of the pipeline is applied in the first load step, and the pigging movement load is applied from the second load step to the last load step. Based on the initial value of the pipeline displacement and the pigging moving load, the dynamic response model is dynamically solved to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process.

2. The method as described in claim 1, characterized in that, The basic data for the natural gas cable crossing pipeline includes: The length of the pipeline, the pipe material, and the geometric structure of the suspended section of the pipeline; The quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cable, wind cable guy cable, conjugate main cable, and conjugate guy cable in the cable system; The geometric structure, materials, and connection methods between the tower and the cable system; The connection methods between bridge piers and towers, bridge decks, and pipelines; the composition and materials of the bridge deck, and the connection methods between the bridge deck and pipelines, cable systems, towers, and bridge piers; Data on the pipeline's flow rate, pressure, and elevation, as well as the status of pipeline cleaning operations.

3. The method as described in claim 1, characterized in that, The static simulation model established, which sets the arching height in the middle of the pipe, includes: The static simulation model is simplified by selecting structural element types, setting constraints and contact conditions, adding prestress to the structure, and setting the arching height in the middle of the pipe, resulting in a static simulation model with the arching height in the middle of the pipe set.

4. The method as described in claim 1, characterized in that, The dynamic response model established based on the static simulation model, with the arching height at the middle of the pipe set, includes: Based on the settings in the static simulation model, the static simulation model is converted into the dynamic calculation module, thereby establishing a dynamic response model with the arching height in the middle of the pipe set.

5. The method as described in claim 1, characterized in that, According to the direction of movement of the pig during the pigging process, multiple load steps are sequentially divided on the pipeline in the dynamic response model, including: A specific distance is set according to the direction of movement of the pig during the pigging process and the length of the pipe diameter. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached serves as the end point of one load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps sequentially.

6. The method as described in claim 1, characterized in that, The loading of the pigging movement load from the second load step to the last load step includes: Count the number of load application locations between the second load step and the endpoint coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. ; Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

7. A method for judging the safety conditions of natural gas suspension cable crossing pipeline pigging, characterized in that, include: Using the method described in any one of claims 1-6, the predicted stress and displacement values ​​of the natural gas suspension cable across the pipeline at each of the load loading positions are obtained during the pipeline cleaning process. Based on the predicted stress and displacement values ​​of the natural gas suspension cable across the pipeline at each load loading position, the predicted maximum stress and maximum displacement values ​​of the pipeline at each load loading position are obtained. The condition in which the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig when the pipeline pig is at the same load loading position is determined as the safe operating condition of the pipeline pig at the load loading position, and then the safe operating condition of the pipeline pig at each load loading position is determined.

8. A device for predicting stress and displacement during pigging of a natural gas suspension bridge pipeline, characterized in that, include: The dynamic response model building module is used to build a static simulation model with the arching height in the middle of the pipeline set according to the basic data of the natural gas cable-stayed pipeline; and to build a dynamic response model with the arching height in the middle of the pipeline set according to the static simulation model. The dynamic response model solving module is used to obtain the initial value of the pipeline displacement of the dynamic response model based on the fitted deformation curve equation; according to the movement direction of the pig during the pigging process, multiple load loading positions are divided on the pipeline of the dynamic response model, and corresponding pigging movement loads are added at the load loading positions; based on the initial value of the pipeline displacement and the pigging movement loads, the dynamic response model is dynamically solved to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each load loading position during the pigging process; The dynamic response model solving module includes: The pipeline displacement initial value determination module is used to obtain the pipeline displacement initial value of the dynamic response model based on the following fitted deformation curve equation. In the formula, u t Let u0 be the displacement at time t; u0 is the initial displacement of the pipeline from the horizontal axis; and t is the duration of the cleaning process. L is a dimensionless displacement. p v is the length of the suspension cable spanning the pipeline; p The speed of the pig is denoted by 'x'; x represents the distance from the measuring point to the starting point of the pipeline crossing; L represents the distance from the measuring point to the starting point of the pipeline crossing. s The length of the waste pipe to be cleaned; u a denoted as ρ, where ρ is the maximum displacement of the pipe; D is the outer diameter of the pipe; g is the acceleration due to gravity. The load loading module is used to divide the pipeline in the dynamic response model into multiple load steps according to the movement direction of the pig during the pigging process; the starting position of each load step is used as the load loading position; the static load of the pipeline is loaded in the first load step, and the pigging movement load is loaded from the second load step to the last load step. The dynamic solution module is used to dynamically solve the dynamic response model based on the initial value of the pipeline displacement and the pigging moving load, so as to obtain the predicted stress and displacement values ​​of the natural gas suspension cable crossing the pipeline at each of the load loading positions during the pigging process.

9. The apparatus as claimed in claim 8, characterized in that, In the step of establishing a static simulation model based on the foundation data of the natural gas cable-stayed pipeline, the dynamic response model building module performs the following: The length of the pipeline, the pipe material, and the geometric structure of the suspended section of the pipeline; The quantity, material, spatial configuration, and interconnection method of the main cable, suspenders, wind cable main cable, wind cable guy cable, conjugate main cable, and conjugate guy cable in the cable system; The geometric structure, materials, and connection methods between the tower and the cable system; The connection methods between bridge piers and towers, bridge decks, and pipelines; the composition and materials of the bridge deck, and the connection methods between the bridge deck and pipelines, cable systems, towers, and bridge piers; Data on the pipeline's flow rate, pressure, and elevation, as well as the status of pipeline cleaning operations.

10. The apparatus as claimed in claim 8, characterized in that, The dynamic response model building module includes: The static simulation model building module is used to simplify the static simulation model. It allows you to select the structural element type, set constraints and contact conditions, add prestress to the structure, and set the arching height in the middle of the pipe to obtain a static simulation model with the arching height in the middle of the pipe set. The static simulation model conversion module is used to convert the static simulation model into the dynamic calculation module according to the settings in the static simulation model, thereby establishing a dynamic response model with the arching height in the middle of the pipe set.

11. The apparatus as claimed in claim 8, characterized in that, The load loading module includes: The load step division module is used to set a specific distance based on the pipe diameter, according to the direction of movement of the pig during the pigging process. The pipeline cleaning machine starts from its initial point and operates for each cycle. The distance reached is used as the end point of a load step and the start point of the next load step, thereby dividing the pipeline of the dynamic response model into multiple load steps in sequence; The static load loading module is used to set the starting position of each load step as the load loading position and load the static load on the pipeline in the first load step. The pigging movement load loading module is used to count the number of load loading positions between the second load step and the end coordinates of the pig. Divide the pig's gravity load by The uniformly distributed gravity load value was obtained. Load at each load loading position between the second load step and the end coordinate of the pig. Count the number of load application locations between the end coordinates of the pig and the last load step. Divide the gravity load of the sewage in the pipeline by The uniformly distributed gravity load value was obtained. Load at each load loading position between the end coordinate of the pig and the last load step. .

12. A device for determining the safety conditions of natural gas suspension cable crossing pipeline pigging, characterized in that, include: The stress and displacement maximum value prediction module is used to obtain, using the method as described in claims 1-6, the predicted stress and displacement values ​​of the natural gas cable crossing the pipeline at each load loading position of the pipeline pig during the pipeline pigging process; and based on the predicted stress and displacement values ​​of the natural gas cable crossing the pipeline at each load loading position of the pipeline pig, to obtain the predicted maximum stress and maximum displacement values ​​of the pipeline at each load loading position of the pipeline pig. The safety condition judgment module is used to determine the condition in which the pipeline stress does not exceed the maximum predicted value of the pipeline stress when the pipeline pig is at one of the load loading positions and the pipeline displacement does not exceed the maximum predicted value of the pipeline pig at the same load loading position as the safe operating condition of the pipeline pig at the load loading position, and then to determine the safe operating condition of the pipeline pig at each load loading position.

13. A terminal device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method for predicting the stress and displacement of the natural gas cable-stayed pipeline as described in any one of claims 1-6.

14. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed, implement the natural gas suspension crossing pipeline cleaning stress and displacement prediction method according to any one of claims 1-6.

15. A terminal device, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for determining the safe operating conditions of pipeline cleaning for natural gas cable-stayed crossings as described in claim 7.

16. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed, implement the method for determining the safe operating conditions of natural gas cable-stayed pipeline cleaning as described in claim 7.

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