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CN-121980873-A - Simulation calculation determination method for prefabricated hole size of hole pulling process

CN121980873ACN 121980873 ACN121980873 ACN 121980873ACN-121980873-A

Abstract

The invention relates to the technical field of machining and manufacturing, in particular to a simulation calculation determination method for the size of a prefabricated hole in a hole drawing process, which comprises a modeling stage, a calculation stage and a determination stage. And in the modeling stage, a geometric model of the simulated main pipe and the simulated branch pipe is established according to the preset sizes of the actual main pipe and the target branch pipe, the thermal expansion coefficient of the simulated branch pipe is set to be negative, and a thermal boundary condition is set for the simulated branch pipe so as to input heat to the simulated branch pipe. And in the calculation stage, the simulation branch pipe is heated and contracted towards the root of the simulation branch pipe to form a through hole on the simulation main pipe. And in the determining stage, the size of the through hole is obtained and used as the size of a prefabricated hole formed in the actual main pipe in the hole pulling test. The simulation calculation determination method of the prefabricated hole size of the hole drawing process adopts a reverse design thought, the simulated branched pipes are reversely contracted to finally obtain the predicted size of the prefabricated hole, and the test is carried out according to the predicted size, so that the cost can be reduced, and the efficiency is improved.

Inventors

  • DENG JINGYU
  • GUO YONGJIANG
  • GAO NA
  • HE XUETING

Assignees

  • 上海飞机制造有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. The simulation calculation determination method for the size of the prefabricated hole in the hole pulling process is characterized by comprising the following steps of: The modeling stage comprises the steps of establishing a geometric model of a simulation main pipe (1) and a simulation branch pipe (2) according to preset sizes of an actual main pipe and a target branch pipe, setting a thermal expansion coefficient of the simulation branch pipe (2) to be a negative value, and setting a thermal boundary condition for the simulation branch pipe (2) so as to input heat to the simulation branch pipe (2); A calculation stage, wherein the simulation branch pipe (2) is configured to shrink towards the root of the simulation branch pipe by heating, so as to form a through hole (11) on the simulation main pipe (1); And in the determining stage, the size of the through hole (11) is obtained and used as the size of a prefabricated hole formed on the actual main pipe in the hole pulling test.
  2. 2. The simulation calculation determination method of the hole size of the hole drawing process preform according to claim 1, wherein the modeling stage further comprises setting a pressure boundary condition of the simulation sub-pipe (2), and applying a pressure load F1 to the simulation sub-pipe (2) in a later stage of heating of the simulation sub-pipe (2); The calculation phase further comprises the fact that the simulation branch pipe (2) is configured to be subjected to the pressure load F1 in the later stage of heating, so that the simulation branch pipe (2) is pressed to be completely in a curved surface with the side wall of the simulation main pipe (1) to form the through hole (11).
  3. 3. The simulation calculation determination method of the hole size of the hole drawing process prefabrication according to claim 2, wherein the modeling stage further comprises the steps of establishing a geometric model of a simulation pipe (3), wherein the simulation pipe (3) is a rigid pipe, the simulation pipe (3) is coaxially inserted into the simulation main pipe (1), and the simulation pipe (3) contacts the inner wall of the simulation main pipe (1) so as to prevent the simulation main pipe (1) from being deformed inwards.
  4. 4. The method for determining the simulated calculation of the prefabricated hole size of the hole drawing process according to claim 3, wherein the modeling stage further comprises the step of applying a pressure load F2 on the outer wall of the simulated main pipe (1) so as to prevent the simulated main pipe (1) from being deformed outwards when the simulated sub pipe (2) is contracted or pressed.
  5. 5. A simulation calculation determination method of a prefabricated hole size of a hole drawing process according to claim 3, wherein the temperature of the simulation tube (3) is constrained to be a reference temperature T1 so as to limit the temperature of the simulation main tube (1) within a preset range.
  6. 6. Simulation calculation determination method of a prefabricated hole size for a hole drawing process according to any of the claims 1-5, characterized in that the thermal boundary conditions set for the simulated sub-pipe (2) are heat input to the simulated sub-pipe (2) at the edge (21) remote from the simulated main pipe (1).
  7. 7. The simulation calculation determination method of the hole size of the hole drawing process preform according to any one of claims 1 to 5, wherein the heat input to the simulation sub-pipe (2) is gradually increased as the simulation calculation proceeds.
  8. 8. The method for determining the size of a prefabricated hole of a hole drawing process according to any one of claims 1 to 5, wherein the modeling stage further comprises setting mechanical properties of the simulated main pipe (1) and the simulated sub pipe (2).
  9. 9. The simulation calculation determination method of the hole pulling process preformed hole size according to claim 8, wherein the mechanical properties of the simulation main pipe (1) and the mechanical properties of the simulation sub-pipe (2) are set to be consistent.
  10. 10. The simulation calculation determining method of the hole size of the hole drawing process preform according to any one of claims 1 to 5, wherein the thermodynamic properties of the simulation main pipe (1) and the thermodynamic properties of the simulation sub-pipe (2) are set to be consistent.

Description

Simulation calculation determination method for prefabricated hole size of hole pulling process Technical Field The invention relates to the technical field of machining and manufacturing, in particular to a simulation calculation determination method for the size of a prefabricated hole in a hole drawing process. Background The T-Pull hole drawing process is a preforming means for realizing butt welding of pipe fittings. When the branch pipe is required to be welded on the side wall of the main pipe, a prefabricated hole is required to be formed on the side wall of the main pipe by utilizing a T-Pull hole pulling process, then the branch pipe is pulled out from the prefabricated hole, and then the branch pipe and the branch pipe can be butt-welded. The T-Pull hole pulling process can effectively reduce the difficulty of pipe fitting welding, and avoid the defects of concentrated welding stress, poor stability and the like of the traditional pipe fitting welding mode. And estimating the sizes of the branch pipes according to the sizes of the branch pipes, and estimating the sizes of the prefabricated holes formed in the side walls of the main pipes according to the sizes of the main pipes and the branch pipes. The problem that the preformed hole is unsuitable in size and can cause cracking or uneven end face of the formed branch pipe can directly influence butt welding quality of the branch pipe and the branch pipe. At present, the size of the prefabricated hole is mainly determined by means of process tests and experience, so that the test cost is high, and the test efficiency is low. Disclosure of Invention The invention aims to provide a simulation calculation determination method for the size of a prefabricated hole in a hole drawing process, which can reduce test cost and improve test efficiency. To achieve the purpose, the invention adopts the following technical scheme: The simulation calculation determination method for the size of the prefabricated hole of the hole drawing process comprises the following steps: The modeling stage, namely establishing a geometric model of a simulation main pipe and a simulation branch pipe according to preset sizes of an actual main pipe and a target branch pipe, setting a thermal expansion coefficient of the simulation branch pipe to be a negative value, and setting a thermal boundary condition for the simulation branch pipe so as to input heat to the simulation branch pipe; the calculation stage comprises that the simulation branch pipe is configured to shrink towards the root of the simulation branch pipe after being heated, so as to form a through hole on the simulation main pipe; and in the determining stage, the size of the through hole is obtained and used as the size of a prefabricated hole formed on the actual main pipe in the hole pulling test. Optionally, the modeling stage further comprises setting a pressure boundary condition of the simulated branch pipe, and applying a pressure load F1 to the simulated branch pipe in a later period of heating the simulated branch pipe; The calculation stage further includes the simulated sub-pipe being configured to receive the pressure load F1 at a later stage of heating so that the simulated sub-pipe is pressed to be entirely on a curved surface with a side wall of the simulated main pipe, forming the through hole. Optionally, the modeling stage further comprises establishing a geometric model of a simulation tube, wherein the simulation tube is a rigid tube, the simulation tube is coaxially inserted into the simulation main tube, and the simulation tube contacts the inner wall of the simulation main tube so as to prevent the simulation main tube from being deformed concavely. Optionally, the modeling stage further comprises applying a pressure load F2 to the outer wall of the simulated main pipe to prevent the simulated main pipe from being deformed outwardly when the simulated branch pipe is contracted or compressed. Optionally, the temperature of the simulation tube is constrained to be a reference temperature T1, so that the temperature of the simulation main tube is limited within a preset range. Optionally, the thermal boundary condition set for the analog branch pipe is to input heat to the edge of the analog branch pipe away from the analog main pipe. Optionally, the heat input to the analog manifold is gradually increased as the simulation calculation proceeds. Optionally, the modeling stage further comprises setting mechanical properties of the simulated main pipe and the simulated branch pipe. Optionally, the mechanical properties of the simulated main pipe and the mechanical properties of the simulated branch pipe are set to be consistent. Optionally, the thermodynamic properties of the simulated main pipe and the thermodynamic properties of the simulated branch pipe are set to be consistent. The invention has the beneficial effects that: The invention provides a simulation calculation determination meth