CN-121997619-A - Method, device, equipment, medium and product for determining size of core mould

CN121997619ACN 121997619 ACN121997619 ACN 121997619ACN-121997619-A

Abstract

The application provides a method, a device, equipment, a medium and a product for determining the size of a core mould, wherein the method comprises the steps of establishing a cross section model of a pipeline according to the size of an initial mould, meshing the cross section model of the pipeline, and then endowing each grid unit with a shear relaxation modulus function to obtain a viscoelasticity model of the pipeline; and obtaining the optimized core mold size according to the comparison result of the cross section model and the deformation model. According to the scheme, the cross section model is established according to the size requirement of the pipeline, the viscoelastic model can represent the relaxation modulus of the pipeline under the shearing stress, the environmental conditions of the pipeline in the cooling solidification stage can be extracted through the actual stress and the actual temperature field, and the accuracy of deformation simulation and core die size adjustment is improved, so that the anti-sagging performance of the pipeline is improved.

Inventors

SU CHAO
WU LIPING
HUANG XUDONG
HUANG HONGLIANG
LIU XIAOYAN
XIN WEI
XIA XIAOLIN
ZHAO YUNHUI
HE YING

Assignees

中石油(上海)新材料研究院有限公司
中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (13)

1. A method of sizing a mandrel for use in a mold prepared as a pipe, the method comprising: determining the size of an initial mould according to the size requirement of a pipeline, wherein the initial mould comprises a core mould and a mouth mould, and the cross section of the initial mould is circular; Establishing a cross section model of the pipeline according to the size of the initial mould, and carrying out grid division on the cross section model of the pipeline to obtain a plurality of grid units; Obtaining an actual stress and an actual temperature field of a pipeline prepared by adopting the initial die to perform extrusion molding process in a cooling solidification stage, and performing deformation simulation on the viscoelastic model according to the actual stress and the actual temperature field to obtain a deformation model of the pipeline, wherein the actual temperature field represents the temperature change of different areas of the pipeline after the extrusion molding process is performed; and adjusting the size of the core mold in the initial mold according to the comparison result of the cross section model and the deformation model to obtain the optimized core mold size.
2. The method according to claim 1, wherein the method further comprises: obtaining fixed shear relaxation moduli at different temperatures; the shear relaxation modulus function is established according to the sum of the fixed shear relaxation modulus at different temperatures and at least one dynamic shear relaxation modulus related to temperature, and is: Wherein G e is a fixed shear relaxation modulus, G i (t) is an ith dynamic shear relaxation modulus, N is the number of the dynamic shear relaxation moduli, t is the cooling time of the pipeline, and the dynamic shear relaxation moduli are: Where g i is the fixed component of the i-th dynamic shear relaxation modulus and τ i is the relaxation time at the i-th dynamic shear relaxation modulus.
3. The method of claim 2, wherein said establishing said shear relaxation modulus function from said summing of said fixed shear relaxation moduli at different temperatures and at least one dynamic shear relaxation modulus associated with temperature comprises: Acquiring shear relaxation modulus values of materials of the pipeline at different temperatures; Taking an exponential function taking the temperature as an independent variable as a fixed component of the shear relaxation modulus, taking a quadratic function taking the temperature as the independent variable as the relaxation time, and determining an initial value of the fixed shear relaxation modulus and an initial value of the number of dynamic shear relaxation moduli to establish an initial shear relaxation modulus function; And if the loss value is not less than the threshold value, the number of coefficients in the exponential function and the quadratic function, the fixed shear relaxation modulus and the dynamic shear relaxation modulus is adjusted until the loss value is less than the threshold value.
4. The method of claim 1, wherein said adjusting the size of the mandrel in the initial mold based on the comparison of the cross-sectional model and the deformation model comprises: Detecting the size relation between the thickness of the pipeline corresponding to the cross section model and the thickness of the pipeline corresponding to the deformation model in a preset direction outwards from the center of the circle in the cross section model; If the thickness of the pipeline corresponding to the cross section model is smaller than that of the pipeline corresponding to the deformation model in the direction, the radius length of the core mould in the direction is increased; And if the thickness of the pipeline corresponding to the cross section model is larger than that of the pipeline corresponding to the deformation model in the direction, reducing the radius length of the core mould in the direction.
5. The method of claim 4, wherein the predetermined direction comprises a first direction and a second direction opposite to each other parallel to a direction of gravity, and a third direction and a fourth direction opposite to each other perpendicular to the direction of gravity.
6. The method of claim 1, wherein after the optimized mandrel dimensions are obtained, further comprising: And (3) performing curve fitting on the profile of the cross section of the mandrel so that the profile consists of two curve joints with semi-elliptic shapes.
7. The method of claim 1, wherein after the optimized mandrel dimensions are obtained, further comprising: Establishing a current cross section model of a pipeline according to the size of a current mould, carrying out grid division on the current cross section model, and endowing each grid unit with the shear relaxation modulus function to obtain a current viscoelastic model; Obtaining a test stress and a test temperature field of a pipeline in a cooling solidification stage, which are obtained after the extrusion molding process is carried out by adopting a current die, and carrying out deformation simulation on the current viscoelastic model according to the test stress and the test temperature field to obtain a current deformation model; Judging whether the comparison result of the cross section model obtained based on the initial die and the current deformation model is consistent, if so, determining the size of the core die, and if not, continuing to adjust the size of the core die.
8. The method according to any one of claims 1 to 7, further comprising: and establishing a database, wherein the database comprises mandrel sizes corresponding to different preparation information, and the preparation information comprises the size of the pipeline, the material of the pipeline and the preparation temperature of the pipeline.
9. The method of claim 8, wherein the method further comprises: According to the preparation information of the current pipeline preparation, determining the core mould size matched with the pipeline preparation requirement from the database; And selecting a core mould with a corresponding size as the core mould used for the preparation of the pipeline according to the core mould size matched with the pipeline preparation requirement.
10. A sizing device for a mandrel, comprising: The device comprises an initial module, a pipeline and a pipeline, wherein the initial module is used for determining the size of an initial mould according to the size requirement of the pipeline, the initial mould comprises a core mould and a neck mould, and the cross section of the initial mould is circular; The processing module is used for establishing a cross section model of the pipeline according to the size of the initial mould, and carrying out grid division on the cross section model of the pipeline to obtain a plurality of grid units; The simulation module is used for obtaining actual stress and an actual temperature field of the pipeline prepared by adopting the initial die to perform extrusion molding process in a cooling solidification stage, and performing deformation simulation on the viscoelastic model according to the actual stress and the actual temperature field to obtain a deformation model of the pipeline, wherein the actual temperature field represents temperature changes of different areas of the pipeline after the extrusion molding process is performed; and the optimization module is used for adjusting the size of the core mould in the initial mould according to the comparison result of the cross section model and the deformation model to obtain the optimized core mould size.
11. An electronic device comprising a processor and a memory communicatively coupled to the processor, the memory storing computer-executable instructions, the processor executing the computer-executable instructions stored in the memory to implement the method of any one of claims 1 to 9.
12. A computer readable storage medium having stored therein computer executable instructions which when executed by a processor are adapted to carry out the method of any one of claims 1 to 9.
13. A computer program product comprising a computer program which, when executed by a processor, implements the method of any one of claims 1 to 9.

Description

Method, device, equipment, medium and product for determining size of core mould Technical Field The application relates to the technical field of pipeline production, in particular to a method, a device, equipment, a medium and a product for determining the size of a core mould. Background In a pipe extrusion process, a material is extruded through a die at an elevated temperature to form a pipe of a desired size. In the cooling stage after the pipe is extruded from the die, the gravity action causes the pipe to generate a sagging phenomenon in the vertical direction, and the consistency and the reliability of the pipe are affected. One current approach to pipe sag resistance is to reduce material deformation by improving the formulation of the pipe material, such as adding reinforcing materials such as fiberglass, to increase the mechanical strength and rigidity of the pipe. The reinforcement in this solution increases the cost of the pipe production and increases the processing difficulty and equipment loss. Another solution to the sagging resistance of the pipe is to reduce the sagging phenomenon by adjusting the position of the core mold in the mold, but the sagging resistance effect of this solution is limited. Therefore, the problem that needs to be solved at present is how to improve the sagging resistance of the pipeline. Disclosure of Invention The application provides a method, a device, equipment, a medium and a product for determining the size of a core mould, which are used for improving the anti-sagging performance of a pipeline. In one aspect, the application provides a method for sizing a mandrel for use as a mold for pipe preparation, the method comprising sizing an initial mold according to a pipe sizing requirement; the initial die comprises a core die and a neck die, the cross section of the initial die is circular, a cross section model of a pipeline is built according to the size of the initial die, grid division is conducted on the cross section model of the pipeline to obtain a plurality of grid units, a shear relaxation modulus function is given to each grid unit to obtain a viscoelasticity model of the pipeline, actual stress and an actual temperature field of the pipeline, which are prepared by adopting the initial die to conduct extrusion molding process, are obtained in a cooling solidification stage, deformation simulation is conducted on the viscoelasticity model according to the actual stress and the actual temperature field to obtain a deformation model of the pipeline, wherein the actual temperature field represents temperature changes of different areas of the pipeline after the extrusion molding process is conducted, and the size of the core die in the initial die is adjusted according to comparison results of the cross section model and the deformation model to obtain the optimized core die size. In one possible implementation, the method further comprises obtaining a fixed shear relaxation modulus at different temperatures, creating a shear relaxation modulus function from a sum of the fixed shear relaxation modulus at different temperatures and at least one dynamic shear relaxation modulus associated with the temperature, the shear relaxation modulus function being: Wherein G e is a fixed shear relaxation modulus, G i (t) is an ith dynamic shear relaxation modulus, N is the number of dynamic shear relaxation moduli, t is the cooling time of the pipeline, and the dynamic shear relaxation modulus is: Where g i is the fixed component of the i-th dynamic shear relaxation modulus and τ i is the relaxation time at the i-th dynamic shear relaxation modulus. In one possible implementation, the shear relaxation modulus function is established according to the sum of the fixed shear relaxation modulus at different temperatures and at least one dynamic shear relaxation modulus related to the temperature, and comprises the steps of obtaining shear relaxation modulus values of materials of a pipeline at different temperatures, taking an exponential function taking the temperature as an independent variable as a fixed component of the shear relaxation modulus, taking a quadratic function taking the temperature as the independent variable as relaxation time, determining an initial value of the fixed shear relaxation modulus and an initial value of the number of the dynamic shear relaxation moduli to establish an initial shear relaxation modulus function, establishing a loss based on the shear relaxation modulus values and the value output by the initial shear relaxation modulus function, determining the shear relaxation modulus function if the loss value is smaller than a threshold value, and adjusting coefficients in the exponential function and the quadratic function, the fixed shear relaxation modulus and the number of the dynamic shear relaxation modulus until the loss value is smaller than the threshold value. In one possible implementation, the dimension of the mandrel in the