CN110837693B - Method for simplifying limited boundary of pressure container - Google Patents
Method for simplifying limited boundary of pressure container Download PDFInfo
- Publication number
- CN110837693B CN110837693B CN201911004409.XA CN201911004409A CN110837693B CN 110837693 B CN110837693 B CN 110837693B CN 201911004409 A CN201911004409 A CN 201911004409A CN 110837693 B CN110837693 B CN 110837693B
- Authority
- CN
- China
- Prior art keywords
- boundary
- stress
- simplified
- pressure
- model
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Measuring Fluid Pressure (AREA)
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
Abstract
The invention relates to the technical field of pressure vessels, in particular to a method for simplifying the limited boundary of a pressure vessel, which comprises the following steps: obtaining an analysis object simplified model according to the analysis model structural characteristics and the region of interest; step two: the axisymmetric stress field based on the elasticity theory obtains a pressure equalizing thick wall stress field expression; step three: acquiring inner diameter parameters and outer diameter parameters of the boundary of the simplified model of the analysis object, and acquiring the axial stress of the simplified boundary of the simplified model of the analysis object based on the pressure-equalizing thick-wall stress field expression obtained in the second step; step four: and performing simplified boundary processing of the simulation model. According to the invention, the finite element integral model is simplified, and meanwhile, the influence of an actual boundary on an analysis object is fully considered, so that the boundary constraint condition in the simulation process is selected, and the accuracy of the simulation process of the pressure vessel is improved.
Description
Technical Field
The invention relates to the technical field of pressure vessels, in particular to a method for simplifying the limited boundary of a pressure vessel.
Background
In the design of pressure vessels, the analysis and verification effort required by the design engineers is very extensive, especially in the face of new product designs and trials, which are burdensome. The traditional analysis and verification work is mainly based on related formulas and coefficients of a design manual, and analysis and verification of structures are carried out in a quite simplified manner. Under such simplified computational analysis, physical prototypes are unavoidable, and repeated modifications of the solution also result in multiple physical prototypes, immeasurable in terms of both cycle and cost. With the development of computers, related finite element algorithms are becoming mature, and the application of finite element simulation software is becoming wider and wider in the field of pressure vessel design.
However, in a specific simulation process, some problems still exist to influence the accuracy of the result. The accuracy of the simulation result is affected by the selection of material parameters and physical models, the setting of material parameters, the loading of boundary conditions, the determination of loads, the selection of a solver, the interpretation of the result and the like. The selection of the boundary constraint conditions is not only an important factor influencing the result, but also the experience and the capability of the simulation engineer. There is no effective boundary simplification method in the existing research.
Disclosure of Invention
The invention aims to provide a finite element boundary simplifying method of a pressure container, which is used for realizing the selection of boundary constraint conditions in the simulation process and improving the accuracy of the simulation process of the pressure container.
In order to achieve the above object, the present invention provides a method for simplifying the limited boundary of a pressure vessel, comprising the steps of:
step one: obtaining an analysis object simplified model according to the analysis model structural characteristics and the region of interest;
step two: the axisymmetric stress field based on the elasticity theory obtains a pressure equalizing thick wall stress field expression;
step three: acquiring inner diameter parameters and outer diameter parameters of the boundary of the simplified model of the analysis object, and acquiring the axial stress of the simplified boundary of the simplified model of the analysis object based on the pressure-equalizing thick-wall stress field expression obtained in the second step;
step four: and performing simplified boundary processing of the simulation model.
Optionally, in the step one, the step of obtaining the simplified model of the analysis object includes:
1) Connecting the adapter with the analysis model;
2) Simplifying the takeover and the analysis model to obtain an analysis object simplified model containing the takeover boundary.
Optionally, in the first step, the method for obtaining the simplified model of the analysis object includes: and (5) performing simplified analysis by intercepting part of the model.
Optionally, in the second step, the step of obtaining the expression of the pressure equalizing thick wall stress field includes:
1) The polar coordinates are selected, so that the boundary line of the simplified model of the analysis object is overlapped with the coordinate system line of the polar coordinates, and the elasticity theory problem is converted into the plane axisymmetry problem, and then the method comprises the following steps:
wherein sigma r Is radial stress, sigma θ Is circumferential stress, r is the distance from the radius direction to the center of circle, τ rθ Is tangential stress along the circumferential direction on a plane with vertical radius, and phi is an Airy stress function;
and (3) analyzing the boundary line of the object simplified model on the polar coordinate, wherein the sector-shaped infinitesimal of the polar coordinate before deformation still keeps sector shape after deformation, so that the stress component can be obtained:
τ rθ ＝0；
thus, the strain component of the plane stress problem can be obtained:
γ rθ ＝0；
wherein, the integral constant A, B, C is determined by boundary conditions, E is the elastic modulus of the material, and v is the Poisson's ratio;
2) Stress expression of pressure equalizing thick-wall cylinder
Corresponding to the pressure equalizing thick-wall cylinder, the inner surface r i Internal pressure p at =a i At the outer surface r o =b is subjected to external pressure p o Therefore, the corresponding boundary conditions of the pressure equalizing thick-wall cylinder are as follows:
the stress distribution expression of the pressure equalizing thick-wall cylinder can be obtained:
τ rθ ＝0；
axial stress sigma due to plane stress z =0, whereas the axial stress of plane strain is a non-zero value, therefore the equalizing thick wall stress field expression is:
optionally, in step three, since the adapter is only subjected to internal pressure, the external pressure is zero, i.e. p o =0, then there is:
τ rθ ＝0；
therefore, the axial stress of the nipple simplified boundary is:
the embodiment of the invention has the following technical effects:
according to the invention, the finite element integral model is simplified, and meanwhile, the influence of an actual boundary on an analysis object is fully considered, so that the boundary constraint condition in the simulation process is selected, and the accuracy of the simulation process of the pressure vessel is improved.
In addition, the method solves the problem that in the current simulation application of the pressure vessel, the boundary of the vessel is simplified and unreasonable, has universality, is suitable for the engineering that the geometric shape is a cylindrical body and the cross section shape is kept unchanged along the shape mandrel Z, such as the parts of the high-pressure vessel, the air cylinder, the cylinder body, the turntable and the like, and has important guiding significance for the subsequent engineering application.
Drawings
FIG. 1 is a block flow diagram of a preferred embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of the boundary conditions for the connection of the valve housing to the nipple in accordance with the preferred embodiment 1 of the present invention;
FIG. 3 is a force analysis diagram of a nipple in accordance with a preferred embodiment 1 of the present invention;
fig. 4 is a schematic diagram showing boundary conditions of the pressure vessel in the preferred embodiment 2 of the present invention.
Detailed Description
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
Referring to fig. 1, the present embodiment provides a method for simplifying the limited boundary of a pressure vessel, comprising the steps of:
step one: according to the structural characteristics and the region of interest of the analysis model, an analysis object simplified model is obtained, and in this embodiment, the step of obtaining the analysis object simplified model includes:
1) Connecting the adapter with the analysis model;
2) Simplifying the takeover and the analysis model to obtain an analysis object simplified model containing the takeover boundary.
At this time, the boundary problem is transferred to the takeover, and the selection of the length of the takeover and the boundary condition of the takeover boundary are considered;
step two: the axisymmetric stress field based on the elasticity theory obtains a pressure equalizing thick wall stress field expression;
step three: acquiring internal and external diameter parameters and internal pressure parameters of the connecting pipe, and obtaining the axial stress of the simplified boundary of the connecting pipe based on the pressure-equalizing thick-wall stress field expression obtained in the step two;
step four: and performing simplified boundary processing of the simulation model.
According to the invention, the finite element integral model is simplified, and meanwhile, the influence of an actual boundary on an analysis object is fully considered, so that the boundary constraint condition in the simulation process is selected, and the accuracy of the simulation process of the pressure vessel is improved.
Referring to fig. 2 and 3, in the structural simulation analysis of the valve housing, although the object of analysis is the housing, it is often impossible to perform the simulation analysis only on the housing because the housing expands when subjected to internal pressure and receives a restraining force from the pipe to it, and therefore, in this embodiment, the adapter and the housing are put into the analysis model as a and B boundaries shown in fig. 2.
The elastic theory problem is a side value problem of a partial differential equation, once a basic unknown quantity is selected, after a corresponding constant solution equation is obtained, each specific solution example only solves the equation in the same domain under different boundary conditions. Clearly, the establishment of boundary conditions plays a decisive role in the resolution of the problem. In general, when the boundary line of the object coincides with the coordinate line, the boundary adjustment is made simplest, so it is more convenient to select polar coordinates for the circular or annular pipe in this embodiment, i.e. in step two, the step of obtaining the expression of the uniform pressure thick wall stress field comprises:
1) The polar coordinates are selected, so that the boundary line of the simplified model of the analysis object is overlapped with the coordinate system line of the polar coordinates, and the elasticity theory problem is converted into the plane axisymmetry problem, and then the method comprises the following steps:
wherein sigma r Is radial stress, sigma θ Is circumferential stress, r is the distance from the radius direction to the center of circle, τ rθ Is tangential stress along the circumferential direction on a plane with vertical radius, and phi is an Airy stress function;
and (3) analyzing the boundary line of the object simplified model on the polar coordinate, wherein the sector-shaped infinitesimal of the polar coordinate before deformation still keeps sector shape after deformation, so that the stress component can be obtained:
τ rθ ＝0；
thus, the strain component of the plane stress problem can be obtained:
γ rθ ＝0；
where the integration constant A, B, C is determined by boundary conditions, E is the modulus of elasticity of the material and v is the Poisson's ratio.
Specifically, the integral constant is a coefficient to be determined of a differential equation, the corresponding differential equation is a differential equation of an axisymmetric problem stress function, and the method belongs to conventional technical means for those skilled in the art, for example, a circular domain or a circular domain which is closed in a circumferential direction, a single-value condition of displacement requires b=0, and for the circular domain, in order to prevent infinite stress at a circle center r=0, a=0 is required.
2) Stress expression of pressure equalizing thick-wall cylinder
Corresponding to the pressure equalizing thick-wall cylinder, the inner surface r i Internal pressure p at =a i At the outer surface r o =b is subjected to external pressure p o Therefore, the corresponding boundary conditions of the pressure equalizing thick-wall cylinder are as follows:
the stress distribution expression of the pressure equalizing thick-wall cylinder can be obtained:
τ rθ ＝0；
the stress distribution expression of the pressure equalizing thick-wall cylinder is irrelevant to the elastic constant, so that the pressure equalizing thick-wall cylinder is applicable to two plane problems at the same time, and axial stress sigma in plane stress is equal to that of the pressure equalizing thick-wall cylinder z =0, whereas the axial stress of plane strain is a non-zero value, therefore the equalizing thick wall stress field expression is:
further, in the present embodiment, since the adapter is subjected to only the internal pressure, the external pressure is zero, i.e., p o Because of this, in combination with step two, the axial stresses required to obtain the reduced boundary of the nipple in step three are:
τ rθ ＝0；
therefore, the axial stress of the nipple simplified boundary is:
in the structural simulation analysis of the corresponding valve housing in this embodiment, the accurate handling of the inlet and outlet constraint modes of the two ends of the pipeline should be to give axial stress sigma on the section according to the internal pressure and the inner and outer diameters of the pipe wall z As a processing method. Thus not increasing the integral structureRigidity, and the influence of deformation of the connecting pipe on the valve are considered.
In addition, in the simulation analysis in other pressure vessels, the determination of the boundary condition can be performed in this way for both the cylindrical pressure vessel body and the cylindrical connection pipe without the need for an additional connection pipe, and thus, as will be understood by those skilled in the art based on the present technical principle, when implementing the present embodiment 2, referring to fig. 4, a difference from embodiment 1 is that in the step one, the method for obtaining the simplified model of the analysis object is: and (5) performing simplified analysis by intercepting part of the model.
In conclusion, the method simplifies the finite element integral model, fully considers the influence of the actual boundary on the analysis object, realizes the selection of boundary constraint conditions in the simulation process, and improves the accuracy of the pressure vessel simulation process.
In addition, the method solves the problem that in the current simulation application of the pressure vessel, the boundary of the vessel is simplified and unreasonable, has universality, is suitable for the engineering that the geometric shape is a cylindrical body and the cross section shape is kept unchanged along the shape mandrel Z, such as the parts of the high-pressure vessel, the air cylinder, the cylinder body, the turntable and the like, and has important guiding significance for the subsequent engineering application.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present invention, and these modifications and substitutions should also be considered as being within the scope of the present invention.
Claims (2)
1. A method of simplifying the finite boundary of a pressure vessel, comprising the steps of:
step one: obtaining an analysis object simplified model according to the analysis model structural characteristics and the region of interest;
step two: the axisymmetric stress field based on the elasticity theory obtains a pressure equalizing thick wall stress field expression;
step three: acquiring inner diameter parameters and outer diameter parameters of the boundary of the simplified model of the analysis object, and acquiring the axial stress of the simplified boundary of the simplified model of the analysis object based on the pressure-equalizing thick-wall stress field expression obtained in the second step;
step four: performing simplified boundary processing of the simulation model;
in the first step, the step of obtaining the simplified model of the analysis object includes:
1) Connecting the adapter with the analysis model;
2) Simplifying the takeover and the analysis model to obtain an analysis object simplified model containing a takeover boundary;
in the second step, the step of obtaining the expression of the pressure equalizing thick wall stress field comprises the following steps:
1) The polar coordinates are selected, so that the boundary line of the simplified model of the analysis object is overlapped with the coordinate system line of the polar coordinates, and the elasticity theory problem is converted into the plane axisymmetry problem, and then the method comprises the following steps:
wherein sigma r Is radial stress, sigma θ Is circumferential stress, r is the distance from the radius direction to the center of circle, τ rθ Is tangential stress along the circumferential direction on a plane with vertical radius, and phi is an Airy stress function;
and (3) analyzing the boundary line of the object simplified model on the polar coordinate, wherein the sector-shaped infinitesimal of the polar coordinate before deformation still keeps sector shape after deformation, so that the stress component can be obtained:
τ rθ ＝0；
thus, the strain component of the plane stress problem can be obtained:
γ rθ ＝0；
wherein, the integral constant A, B, C is determined by boundary conditions, E is the elastic modulus of the material, and v is the Poisson's ratio;
2) Stress expression of pressure equalizing thick-wall cylinder
Corresponding to the pressure equalizing thick-wall cylinder, the inner surface r i Internal pressure p at =a i At the outer surface r o =b is subjected to external pressure p o Therefore, the corresponding boundary conditions of the pressure equalizing thick-wall cylinder are as follows:
r i ＝a；
τ rθ ＝0
r o ＝b；
τ rθ ＝0；
the stress distribution expression of the pressure equalizing thick-wall cylinder can be obtained:
τ rθ ＝0；
axial stress sigma due to plane stress z =0, whereas the axial stress of the plane strain is a non-zero value, therefore the uniform pressure thick wall stress field expressionThe formula is:
in the third step, the connecting pipe is only subjected to internal pressure, and the external pressure is zero, namely p o =0, then there is:
τ rθ ＝0；
therefore, the axial stress of the nipple simplified boundary is:
2. the method for simplifying the finite boundary of a pressure vessel according to claim 1, wherein in the first step, the method for obtaining the simplified model of the analysis object is as follows: and (5) performing simplified analysis by intercepting part of the model.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911004409.XA CN110837693B (en) | 2019-10-21 | 2019-10-21 | Method for simplifying limited boundary of pressure container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911004409.XA CN110837693B (en) | 2019-10-21 | 2019-10-21 | Method for simplifying limited boundary of pressure container |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110837693A CN110837693A (en) | 2020-02-25 |
| CN110837693B true CN110837693B (en) | 2023-05-12 |
Family
ID=69575521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911004409.XA Active CN110837693B (en) | 2019-10-21 | 2019-10-21 | Method for simplifying limited boundary of pressure container |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110837693B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4591996A (en) * | 1981-05-18 | 1986-05-27 | Vachon Reginald I | Apparatus and method for determining stress and strain in pipes, pressure vessels, structural members and other deformable bodies |
| JPH0571643A (en) * | 1991-09-09 | 1993-03-23 | Mitsubishi Heavy Ind Ltd | End plate structure of pressure vessel |
| CN101655829A (en) * | 2009-09-14 | 2010-02-24 | 湖南师范大学 | External pressure self-intensification cylinder and design calculation and manufacturing method thereof |
| CN102184289A (en) * | 2011-05-06 | 2011-09-14 | 大连船舶重工集团装备制造有限公司 | Method for carrying out stress analysis on first-class nuclear reactors through using ANSYS software |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110024431A1 (en) * | 2008-03-28 | 2011-02-03 | Kyocera Corporation | Pressure Container, and Buoyant Body and Exploratory Apparatus Provided Therewith |
-
2019
- 2019-10-21 CN CN201911004409.XA patent/CN110837693B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4591996A (en) * | 1981-05-18 | 1986-05-27 | Vachon Reginald I | Apparatus and method for determining stress and strain in pipes, pressure vessels, structural members and other deformable bodies |
| JPH0571643A (en) * | 1991-09-09 | 1993-03-23 | Mitsubishi Heavy Ind Ltd | End plate structure of pressure vessel |
| CN101655829A (en) * | 2009-09-14 | 2010-02-24 | 湖南师范大学 | External pressure self-intensification cylinder and design calculation and manufacturing method thereof |
| CN102184289A (en) * | 2011-05-06 | 2011-09-14 | 大连船舶重工集团装备制造有限公司 | Method for carrying out stress analysis on first-class nuclear reactors through using ANSYS software |
Non-Patent Citations (5)
| Title |
|---|
| Naki Tutuncu et al..A novel approach to stress analysis of pressurized FGM cylinders, disks and spheres.《Composite Structures》.2009,第91卷385–390. * |
| Y. Z. CHEN.STUDY OF MULTIPLY-LAYERED CYLINDERS MADE OF FUNCTIONALLY GRADED MATERIALS USING THE TRANSFER MATRIX METHOD.《JOURNAL OF MECHANICS OF MATERIALS AND STRUCTURES》.2011,第6卷(第5期),641-657. * |
| Y.Z. Chen et al..An alternative numerical solution of thick-walled cylinders and spheres made of functionally graded materials.《Computational Materials Science 》.2010,第48卷640–647. * |
| 陈勇军.单层厚壁圆筒弹性动应力的简化计算方法.《工程力学》.2006,第23卷(第11期),第45-51页. * |
| 陈非凡等.压力容器应力、变形分析与数值验证.《化学工程与装备》.2017,(第2期),第58-60页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110837693A (en) | 2020-02-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106383955B (en) | Data interconversion method for stress analysis and three-dimensional model in pipeline design | |
| US7347083B2 (en) | System and method for detecting a leak in a hydraulic fluid system | |
| CN111046505B (en) | Axial flow pump spoke parameter optimization design method based on response surface model | |
| CN113722956B (en) | Method for predicting assembly tightness of flaring catheter | |
| CN110762268A (en) | Method for designing internal dimension of regulating valve | |
| CN103823406A (en) | Numerical control machine tool sensitive-link identification method based on modal mass distribution matrix | |
| CN110837693B (en) | Method for simplifying limited boundary of pressure container | |
| CN108460204B (en) | Method for reversely deducing dynamic mechanical parameters of material of loudspeaker through stress and displacement of vibrating part of loudspeaker | |
| WO2024066281A1 (en) | Piston profile design method, piston, and internal combustion engine system | |
| CN111062127B (en) | Pipeline leakage point detection method and device, storage medium and terminal | |
| CN112100761A (en) | Dynamic response analysis and vibration reduction optimization design method for rocket engine pipeline | |
| JP6973377B2 (en) | Analyst, analysis method, and program | |
| CN116011183B (en) | In-service oil and gas pipeline detection method, device, equipment and storage medium | |
| CN117129179A (en) | Mach number correction method for double-support test under continuous wind tunnel wing | |
| CN117077322A (en) | Design method of motor cooling flow channel | |
| CN109599193B (en) | Spiral tube heat exchanger flow induced vibration test simulation device and test method thereof | |
| CN107766621B (en) | Nuclear power station overhead HDPE (high-density polyethylene) pipeline functionality verification method and system | |
| CN110909420B (en) | Ship propulsion shafting alignment iterative calculation method considering bearing factors | |
| CN109255171B (en) | Method for automatically judging convergence of numerical simulation calculation | |
| CN112347583A (en) | Method for calculating limit internal pressure of double-defect-contained bent pipe of booster station | |
| CN106770627B (en) | Axial magnetic flux leakage signal length quantization method | |
| Lin et al. | Optimization of bending process parameters for seamless tubes using Taguchi method and finite element method | |
| CN114112176B (en) | Design method of external pipeline connected with surge pressure difference or pressure sensor | |
| CN114415748B (en) | Sleeve regulating valve resistance coefficient estimation method and system considering cavitation influence | |
| Bartsch et al. | Quasi Two-Dimensional Flow-Adaptive Algorithm for Pneumatic Probe Measurements |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: No. 8 Qishan Road, Shiqi Town, Panyu District, Guangzhou City, Guangdong Province, 510000, 150 Patentee after: Radio and TV Measurement and Testing Group Co.,Ltd. Address before: No.163, xipingyun Road, Huangpu Avenue, Tianhe District, Guangzhou, Guangdong 510000 Patentee before: GUANGZHOU GRG METROLOGY & TEST Co.,Ltd. |
|
| CP03 | Change of name, title or address |