A method for calculating the bursting pressure of steel-reinforced polyethylene plastic composite pipes

Abstract

A method for calculating the bursting pressure of a steel-reinforced polyethylene plastic composite pipe relates to the technical field of mechanical engineering mechanics and includes model establishment, analysis step establishment, and pressure simulation. The model establishment includes determining simulation parameters, establishing a three-dimensional finite element model, and assembling the model; the analysis step establishment includes dividing a grid and setting a bursting pressure output; and the pressure simulation includes applying a pressure simulation condition and extracting the bursting pressure. The method utilizes finite element simulation technology to perform three-dimensional modeling of the steel-reinforced polyethylene plastic composite pipe, considers the positional relationship between the PE layer and the longitude and latitude lines, and sets analysis steps according to the actual pressure environment to simulate the bursting process of the steel-reinforced polyethylene plastic composite pipe, thereby obtaining the bursting pressure of the steel-reinforced polyethylene plastic composite pipe. The method has the characteristics of easy operation, high prediction accuracy, energy saving and environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical engineering mechanics, and in particular to a method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe. Background Art

[0002] Steel-reinforced polyethylene (PE) plastic composite pipes, due to their combined rigidity and flexibility, are widely used in the petroleum, chemical, and municipal engineering sectors. Due to their unique structure and the fact that they are pressure-bearing pipes, primarily used to transport flammable and explosive materials, their pressure-bearing capacity determines their safety and reliability. Current research on the pressure-bearing capacity of steel-reinforced polyethylene (PE) plastic composite pipes utilizes a tooling pressure test, known as hydraulic blasting. This method is inefficient and costly, and is particularly challenging for large-diameter pipes. Therefore, a simple and efficient method for extracting blasting pressure is urgently needed to simulate and predict the pressure-bearing capacity of steel-reinforced polyethylene (PE) plastic composite pipes. Summary of the Invention

[0003] The invention proposes a method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe, which has the characteristics of easy operation, high prediction accuracy, and the like.

[0004] The technical solutions of the present invention are as follows:

[0005] A method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe includes model establishment, analysis step establishment, and pressure simulation, and is characterized in that:

[0006] The model establishment includes determining simulation parameters, establishing a three-dimensional finite element model, and assembling the model;

[0007] The analysis step establishment includes dividing the grid and setting the bursting pressure output;

[0008] The pressure simulation includes applying pressure to simulate working conditions and extracting bursting pressure.

[0009] As a further optimization of this solution, the step of determining simulation parameters includes:

[0010] Geometric parameter settings include setting the thickness of the PE layer in the PE pipe, setting the number and diameter of the warp threads, and setting the pitch and diameter of the weft threads.

[0011] Material parameter setting, including setting the density, elastic modulus, Poisson's ratio and specific heat capacity of each material in the composite tube;

[0012] As a further optimization of this solution, the establishment of the three-dimensional finite element model includes establishing a three-dimensional finite element model of the PE pipe and a three-dimensional finite element model of the longitude and latitude lines.

[0013] The establishing of the three-dimensional finite element model of the longitude and latitude includes establishing the three-dimensional finite element model of the longitude and latitude according to the longitude and latitude, the number and diameter of the set longitudes, and the pitch and diameter of the latitudes;

[0014] The establishing of the three-dimensional finite element model of the PE pipe includes establishing the three-dimensional finite element model of the PE pipe according to the thickness of the PE layer, and the density, elastic modulus, Poisson's ratio and specific heat capacity of each material in the composite pipe.

[0015] As a further optimization of this solution, according to the three-dimensional finite element model of the PE pipe and the three-dimensional finite element model of the longitude and latitude lines, assembly is performed according to the actual positional relationship, and the relative positions of the PE pipe and the longitude and latitude lines are adjusted.

[0016] As a further optimization of this solution, the analysis step specifically includes:

[0017] Set pressure parameters, including pressure level, pressure change speed, and pressure change time, to simulate the pressure increase process;

[0018] Set the burst pressure output and integrate the pressure parameters as the pressure output acting on the composite pipe.

[0019] As a further optimization of this solution, the meshing step includes meshing the model, setting the steel skeleton polyethylene plastic composite pipe model to a hexahedral mesh,

[0020] The contact properties between the PE pipe and the longitude and latitude lines are set, and embedded contact is selected to ensure that there is force transmission between the PE pipe and the longitude and latitude lines.

[0021] As a further optimization of this solution, the simulated blasting step includes:

[0022] Boundary condition setting: setting the boundary conditions of the steel skeleton polyethylene plastic composite pipe model and setting the two ends of the steel skeleton plastic composite pipe to be fixed;

[0023] A linear uniformly distributed pressure is set inside the steel skeleton polyethylene plastic composite pipe.

[0024] The working principle and beneficial effects of the present invention are:

[0025] This method is based on ABAQUS software. First, a three-dimensional finite element model of the composite pipe is established based on the actual dimensional parameters of the composite pipe, including the PE layer and longitude and latitude lines. Then, the material properties and boundary conditions of the stressed composite pipe are determined. Pressure is applied to the composite pipe, and the pressure is set to increase linearly. After the composite pipe yields and explodes, the statistical pressure is the composite pipe's bursting pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Figure 1 It is a flowchart of the present invention.

[0028] Figure 2 This is a flowchart of specific embodiment 2. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0030] Specific embodiment 1,

[0031] As the instruction manual Figure 1 A method for calculating the burst pressure of a steel-reinforced polyethylene plastic composite pipe is shown, comprising model establishment, analysis step establishment, and pressure simulation. The model establishment includes determining simulation parameters, establishing a three-dimensional finite element model, and assembling the model; the analysis step establishment includes setting pressure parameters and setting the burst pressure output; the pressure simulation includes meshing, burst simulation, and extracting the burst pressure. The simulation parameter determination step includes base plate setting, including adding and setting PE pipes, warps, and wefts; and geometric parameter setting, including setting the thickness of the PE layer in the PE pipe, the number and diameter of the warps, and the pitch and diameter of the wefts. Material parameter settings include setting the density, elastic modulus, Poisson's ratio, and specific heat capacity of each material in the composite pipe. Creating a three-dimensional finite element model includes creating a 3D finite element model of the PE pipe and a 3D finite element model of the warp and weft lines. Creating the 3D finite element model of the warp and weft lines includes creating a 3D finite element model of the warp and weft lines based on the number and diameter of the warp lines, as well as the pitch and diameter of the weft lines. Creating a 3D finite element model of the PE pipe includes creating a 3D finite element model of the PE pipe based on the thickness of the PE layer and the density, elastic modulus, Poisson's ratio, and specific heat capacity of each material in the composite pipe. Using these 3D finite element models of the PE pipe and the warp and weft lines, assembly is performed according to the actual positional relationship, adjusting the relative positions of the PE pipe and the warp and weft lines.

[0032] This process involves model building. First, the model's coordinate environment is set according to the actual situation, that is, a three-dimensional finite element model is established. The coordinate system is set according to the actual situation. This can be longitude and latitude, or a rectangular coordinate system. Since the composite pipe is cylindrical, a polar coordinate system is more suitable for model building. Since the composite pipe used for simulation uses steel as the skeleton and the main body is the PE layer, the thickness and material of the PE layer, as well as the material, density, elastic modulus, Poisson's ratio, and specific heat capacity of each part of the hybrid pipe, need to be set to achieve consistency with the actual steel-plastic composite pipe. The three-dimensional model of the steel-plastic composite pipe is then combined with the three-dimensional spatial coordinates and embedded, so that every point of the hybrid pipe model can be represented, facilitating subsequent simulation.

[0033] The establishment of the analysis step specifically includes setting the pressure parameters, including setting the pressure size, pressure change speed, pressure change time, and simulating the pressure increase process; and setting the bursting pressure output includes outputting the pressure when the pipe is destroyed after the simulation calculation is completed as the bursting output of the composite pipe.

[0034] The meshing step includes meshing the model, setting the steel skeleton polyethylene plastic composite pipe model to a hexahedral mesh, setting the contact properties between the PE pipe and the longitude and latitude lines, and selecting embedded contact to ensure force transmission between the PE pipe and the longitude and latitude lines.

[0035] This process applies the principle of differentiation to convert the PE pipe into tiny units. Force analysis can be performed on each small unit, including the external pressure and the forces acting within the material. Once the unit analysis is completed, the overall force analysis of the composite pipe can be accurately obtained through integration.

[0036] The simulated blasting step includes setting boundary conditions, setting boundary conditions of the steel skeleton polyethylene plastic composite pipe model, and fixing both ends of the steel skeleton polyethylene plastic composite pipe.

[0037] When simulating the bursting pressure, it is necessary to fix the two end points of the composite pipe to simulate the infinite length of the pipe. After the composite pipe yields and bursts, the bursting pressure value is output and counted.

[0038] Specific embodiment 2,

[0039] As the instruction manual Figure 2 As shown, a method for extracting the bursting pressure of a steel skeleton polyethylene plastic composite pipe based on three-dimensional simulation analysis is provided. The method is supported by ABAQUS software and includes the following steps:

[0040] a. Establish a three-dimensional finite element model based on the parameters of the PE layer of the steel skeleton polyethylene plastic composite pipe, including the inner diameter, outer diameter, and length;

[0041] b. Establish a three-dimensional finite element model based on the warp parameters of the steel skeleton polyethylene plastic composite pipe, the warp parameters include: diameter, number of roots, and length;

[0042] c. Establish a three-dimensional finite element model based on the parameters of the weft of the steel skeleton polyethylene plastic composite pipe, the weft parameters include: diameter, pitch, and length;

[0043] d. According to the material properties of the steel skeleton polyethylene plastic composite pipe, set the material parameters of the steel skeleton polyethylene plastic composite pipe, the material parameters include the density, elastic modulus, Poisson's ratio of the steel skeleton warp and weft and polyethylene;

[0044] e. According to the established three-dimensional finite element model of the PE layer and the longitude and latitude, the relative position of the PE layer and the longitude and latitude is adjusted according to the actual position relationship in the steel skeleton polyethylene plastic composite pipe;

[0045] f. Establish an analysis step to simulate the process of steel-framed polyethylene plastic composite pipe bursting under pressure, and set the output according to the pressure at the time of bursting;

[0046] g. Mesh the model. Use hexahedron-based meshes for both the PE layer and the longitude and latitude lines. Make the mesh as fine as possible to ensure simulation efficiency and results.

[0047] h. Set the contact properties between the PE layer and the longitude and latitude lines. Use embedded contact settings to ensure force transmission between the PE tube and the longitude and latitude lines.

[0048] j. Set the boundary conditions for the steel skeleton polyethylene plastic composite pipe and fix both ends of the steel skeleton polyethylene plastic composite pipe;

[0049] h. Set a linear uniform pressure inside the steel skeleton polyethylene plastic composite pipe;

[0050] i. Run ABAQUS software to extract the pressure of the steel-reinforced plastic composite pipe at the moment of bursting. This pressure is the bursting pressure of the steel-reinforced polyethylene plastic composite pipe.

[0051] Specific embodiment 3,

[0052] Input the technical parameters of the specific embodiment 2,

[0053] A method for extracting the bursting pressure of a steel-reinforced polyethylene plastic composite pipe based on three-dimensional simulation analysis is provided. The method is supported by ABAQUS software and includes the following steps:

[0054] a. A three-dimensional finite element model was established based on the parameters of the PE layer of the steel skeleton polyethylene plastic composite pipe, where the inner diameter of the PE layer is 400 mm, the outer diameter is 430 mm, and the length is 1000 mm;

[0055] b. A three-dimensional finite element model was established based on the parameters of the warp of the steel skeleton polyethylene plastic composite pipe, where the warp diameter was 3 mm, there were 108 pieces, and the length was 1000 mm;

[0056] c. A three-dimensional finite element model was established based on the parameters of the weft of the steel skeleton polyethylene plastic composite pipe, where the weft diameter was 4 mm, the pitch was 14 mm, and the length was 1000 mm;

[0057] d. Set the material parameters for the steel-reinforced polyethylene-plastic composite pipe based on its material properties: the density of the steel-reinforced polyethylene-plastic composite pipe's warp and weft lines is 1800 kg / m³, the elastic modulus is 210,000 MPa, and the Poisson's ratio is 0.26; the density of the PE layer is 970 kg / m³, the elastic modulus is 1002 MPa, and the Poisson's ratio is 0.45;

[0058] e. According to the established three-dimensional finite element model of the PE layer and the longitude and latitude lines, assemble according to its actual positional relationship in the steel skeleton polyethylene plastic composite pipe and adjust the relative position of the PE layer and the longitude and latitude lines;

[0059] f. Establish an analysis step to simulate the blasting process of the steel-framed polyethylene plastic composite pipe and set the output of the blasting pressure;

[0060] g. Grid the model, using hexahedral grids for both the PE layer and the longitude and latitude lines;

[0061] h. Set the contact properties between the PE layer and the longitude and latitude lines, using embedded contact settings to ensure force transmission between the PE tube and the longitude and latitude lines;

[0062] i. Set boundary conditions for the steel skeleton polyethylene plastic composite pipe and fix both ends of the model;

[0063] j. Apply linear uniform pressure inside the steel skeleton polyethylene plastic composite pipe;

[0064] k. Run ABAQUS software and extract the bursting pressure of the steel skeleton plastic composite pipe after the calculation is completed.

[0065] This method uses finite element simulation technology to create a three-dimensional model of a steel-reinforced polyethylene-plastic composite pipe. This method considers the positional relationship between the PE layer and the longitude and latitude lines, and sets analysis steps based on the actual pressure environment to simulate the bursting process of the steel-reinforced polyethylene-plastic composite pipe. This method can determine the bursting pressure of the steel-reinforced polyethylene-plastic composite pipe. This method is characterized by ease of operation, high prediction accuracy, and energy conservation and environmental protection.

[0066] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. 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 calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe, comprising model establishment, analysis step establishment, and pressure simulation, characterized in that: The model establishment includes determining simulation parameters, establishing a three-dimensional finite element model, and assembling the model; The analysis step establishment includes dividing the grid and setting the bursting pressure output; The pressure simulation includes applying a pressure simulation condition and extracting the bursting pressure. The step of determining the simulation parameters includes: Geometric parameter settings include setting the thickness of the PE layer in the PE pipe, setting the number and diameter of the warp threads, setting the pitch and diameter of the weft threads, Material parameter setting includes setting the density, elastic modulus, Poisson's ratio and specific heat capacity of each material in the composite pipe. The establishment of the three-dimensional finite element model includes establishing a three-dimensional finite element model of the PE pipe and a three-dimensional finite element model of the longitude and latitude lines. The establishing of the three-dimensional finite element model of the longitude and latitude includes establishing the three-dimensional finite element model of the longitude and latitude according to the longitude and latitude, the number and diameter of the set longitudes, and the pitch and diameter of the latitudes; The establishing of the three-dimensional finite element model of the PE pipe includes establishing the three-dimensional finite element model of the PE pipe according to the thickness of the PE layer, and the density, elastic modulus, Poisson's ratio and specific heat capacity of each material in the composite pipe.

2. The method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe according to claim 1, characterized in that: According to the three-dimensional finite element model of the PE pipe and the three-dimensional finite element model of the longitude and latitude lines, assembly is performed according to the actual positional relationship, and the relative positions of the PE pipe and the longitude and latitude lines are adjusted.

3. The method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe according to claim 1, characterized in that: The analysis step specifically includes: Set pressure parameters, including pressure level, pressure change speed, and pressure change time, to simulate the pressure increase process; Set the burst pressure output and integrate the pressure parameters as the pressure output acting on the composite pipe.

4. The method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe according to claim 1, characterized in that: The meshing step includes meshing the model, setting the steel skeleton polyethylene plastic composite pipe model to a hexahedral mesh, The contact properties between the PE pipe and the longitude and latitude lines are set, and embedded contact is selected to ensure that there is force transmission between the PE pipe and the longitude and latitude lines.

5. The method for calculating the bursting pressure of a steel skeleton polyethylene plastic composite pipe according to claim 1, characterized in that: The step of applying pressure to simulate working conditions includes: Boundary condition setting: setting the boundary conditions of the steel skeleton polyethylene plastic composite pipe model and setting the two ends of the steel skeleton plastic composite pipe to be fixed; A linear uniformly distributed pressure is set inside the steel skeleton polyethylene plastic composite pipe.

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