CN102194032A - Optimized design method of resin model cavity configuration - Google Patents

Optimized design method of resin model cavity configuration Download PDF

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CN102194032A
CN102194032A CN2011101549794A CN201110154979A CN102194032A CN 102194032 A CN102194032 A CN 102194032A CN 2011101549794 A CN2011101549794 A CN 2011101549794A CN 201110154979 A CN201110154979 A CN 201110154979A CN 102194032 A CN102194032 A CN 102194032A
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shell
design
colophony prototype
model
colophony
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朱继宏
谷小军
张卫红
李军朔
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Northwestern Polytechnical University
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Abstract

The invention discloses an optimized design method of a resin model cavity configuration. The method is used for solving the technical problem that only the same design configuration is applied for different models in the conventional photo-curing quick forming-based precision cast resin cavity design method. The invention adopts the technical scheme that: optimized design of the resin model cavity configuration is realized by adopting a modern topological optimization method, meanwhile, a reasonable cavity structure form is designed aiming at the shape characteristics of different models by considering the stress generated by a resin model to a profile shell and the rigidity of the resin model, optimal matching of stress and rigidity design is achieved, the sand profile shell is prevented from being broken due to thermal expansion of resin, and size precision of the profile shell can be better ensured.

Description

Colophony prototype inner chamber configuration Optimization Design
Technical field
The present invention relates to a kind of colophony prototype inner chamber configuration designing method, particularly a kind of colophony prototype inner chamber configuration Optimization Design.
Background technology
Document " Hague; R.; D ' Costa; G.and Dickens; P.M. (2001), " Structural design and resin drainage characteristics of QuiCkCast 2.0 ", Rapid Prototyping Journal; Vol.7No.2, pp.66-72 " discloses a kind of hot investment casting resin inner chamber method for designing based on photocureable rapid shaping.Because the resin in the rapid shaping both had been different from the plastics vaporization mould in the disappearance mould, was different from the wax-pattern in the investment cast again.Light-cured resin prototype material is than general mould material intensity height, good rigidly, and thermal expansivity very easily causes the spalling of shell than the high magnitude of fine casting shell material in roasting process.So document is taken out shell with colophony prototype, inner chamber is filled with regular honeycomb, reaches the purpose that relaxes shell stress and guarantee colophony prototype rigidity, and has provided three kinds of different inner chamber design configurations.
Change colophony prototype inner chamber material layout though the disclosed method for designing of document is recognized, can relax shell stress and guarantee colophony prototype rigidity, its method for designing still rests on the experience directly perceived, lacks its corresponding theory basis and method.Shortcoming is: for different models, can only use with a kind of design configuration; The rigidity of resin mould is not considered as the leading indicator of structural design yet.
Summary of the invention
In order to overcome existing hot investment casting resin inner chamber method for designing based on photocureable rapid shaping, can only use deficiency for different models with a kind of design configuration, the invention provides a kind of colophony prototype inner chamber configuration Optimization Design.Use modern Topology Optimization Method and realize colophony prototype inner chamber configuration optimal design, consider that simultaneously colophony prototype is to the stress of shell generation and the rigidity of colophony prototype itself, resemblance at different models, can design rational inner-cavity structure form, reach the optimum matching of stress and rigidity Design, avoid the sand mold shell to break, and can guarantee the accuracy to size of shell better because of the resin heat expansion.
The technical solution adopted for the present invention to solve the technical problems is: a kind of colophony prototype inner chamber configuration Optimization Design is characterized in adopting following steps:
(1) sets up geometric model.Earlier the cad model of colophony prototype is taken out shell, take out thickness of the shell and be generally 0.2～2mm; Shell model afterwards is inner fills with taking out.The shell that cad model is pumped into is the non-design domain of topological optimization; Model inside is filled to the design domain of topological optimization.
Colophony prototype cad model outside surface outwards is offset 6mm-10mm, and Offset portion forms shell.
(2) set up finite element model.Geometric model is adopted free grid dividing finite element grid, be defined as PartA.The finite element unit of colophony prototype is wherein duplicated, and displacement is defined as PartB greater than resin mould full-size.
The definition material properties.According to the material type of using, define Young modulus, Poisson ratio, the thermal expansivity of type shell material and resin material respectively.
Load the temperature operating mode.In the shell roasting process, PartA applied 60 ℃ constant temperature field.Because the thermal expansivity of type shell material is than the high about order of magnitude of thermal expansivity of resin material, so shell produces thermal stress.
The on-load pressure operating mode.This process is will be coated with on ready-made colophony prototype surface to hang certain thickness slurry and sand material.In this process, PartB model outside surface will bear a certain size well-distributed pressure load.So add a uniformly distributed load at resin surface.
(3) set up the topological optimization model.
According to the finite element model of setting up, shell and colophony prototype surface cell are non-design domain, and colophony prototype inner chamber unit is a design domain, and the unit of colophony prototype among PartA and the PartB is corresponding one by one, that is:
x i A = x i B = x i ( i = 1,2 . . . n ) - - - 1.1
Wherein
Figure BSA00000514255400022
Be the design variable in the PartA design domain,
Figure BSA00000514255400023
Be the design variable in the PartB design domain, x iDesign variable for the topological optimization definition.
So the mathematic(al) representation of topological optimization is written as:
Find：X＝(x 1，x 2，...，x n)
Min：Max(σ C) 1.2
C &le; C ( U ) V &le; V ( U ) 0 < x ( L ) &le; x i &le; 1 , i = 1,2 , . . . , n
In the formula, X is a design variable vector, i.e. the pseudo-density of material between 0 to 1 on the design domain; C (U)And V (U)The upper limit for deformation energy and volume fraction ratio; Accordingly, x (L)For when unit material is removed, being the lower limit of avoiding the unusual pseudo-density of element stiffness matrix, σ CBe the stress on the shell that under temperature loading, causes by thermal stress.
C is the strain energy of resin mould under well-distributed pressure, and it is the ratio inverse of the rigidity of structure, is written as:
C = 1 2 F P T U P - - - 1.3
In the formula, F PPressure load for the resin mould surface; U PBe the node corresponding motion vector.
(4) find the solution.
Carry out the topological optimization iteration, the colophony prototype design result is saved as stl file, directly make colophony prototype with the photocureable rapid shaping machine.Perhaps according to colophony prototype topological optimization size as a result, the reconstruct cad model forms the inner chamber configuration, directly makes colophony prototype with the photocureable rapid shaping machine again.
The invention has the beneficial effects as follows: owing to adopt modern Topology Optimization Method to realize colophony prototype inner chamber configuration optimal design, consider that simultaneously colophony prototype is to the stress of shell generation and the rigidity of colophony prototype itself, resemblance at different models, design rational inner-cavity structure form, reached the optimum matching of stress and rigidity Design, avoided the sand mold shell to break, and can guarantee the accuracy to size of shell better because of the resin heat expansion.
Below in conjunction with drawings and Examples the present invention is elaborated.
Description of drawings
Fig. 1 is geometric model and the size of embodiment 1 and embodiment 2 in the embodiment.
Fig. 2 is the topological optimization model of embodiment 1 and embodiment 2 in the embodiment.
Fig. 3 is the topological optimization result of embodiment 1 in the embodiment.
Fig. 4 is the topological optimization result of embodiment 2 in the embodiment.
Among the figure, 1-shell, 2-colophony prototype shell, 3-colophony prototype inner chamber; Shell 1 and colophony prototype shell 2 are non-design domain, and colophony prototype inner chamber 3 is a design domain.
Embodiment
Following examples are with reference to Fig. 1～4.
Embodiment 1: colophony prototype inner chamber configuration Optimization Design of the present invention comprises following three key links:
(1) sets up geometric model.Resin mould is of a size of 570mm * 370mm.Because rectangle has symmetry, thus get rectangle 1/4th as finite element model and topological optimization model.
Earlier the cad model of colophony prototype is taken out shell, take out thickness of the shell and be generally 0.2mm-2mm; Shell model afterwards is inner fills with taking out.The shell that cad model is pumped into is the non-design domain of topological optimization; Model inside is filled to the design domain of topological optimization.Colophony prototype cad model outside surface outwards is offset 6mm-10mm, and Offset portion forms shell.
(2) set up finite element model.Geometric model is adopted free grid dividing finite element grid, be defined as PartA.The finite element unit of colophony prototype is wherein duplicated, move a certain distance (greater than resin mould full-size), be defined as PartB.
The material properties of model is as shown in table 1.Finite element model has two operating modes: pressure working condition and temperature operating mode.
Load the temperature operating mode.This process is the shell roasting process, is heated to 60 ℃ simultaneously for shell 1, colophony prototype shell 2 and colophony prototype inner chamber 3.
The on-load pressure operating mode.In shell 1 preparation process, colophony prototype shell 2 and colophony prototype inner chamber 3 will have enough rigidity to bear certain uniformly distributed load, prevent to be out of shape owing to colophony prototype shell 2 and colophony prototype inner chamber 3 rigidity differences, have reduced the accuracy to size of whole model.At colophony prototype shell 2 and the inside pressure 0.4Mpa of colophony prototype inner chamber 3 external load.
Table 1
Figure BSA00000514255400041
(3) set up the topological optimization model.According to the finite element model of setting up, shell 1 and colophony prototype shell Unit 2 are non-design domain, and colophony prototype inner chamber Unit 3 are design domain, and the unit of colophony prototype among PartA and the PartB is corresponding one by one, that is:
x i A = x i B = x i ( i = 1,2 . . . n ) - - - 2.1
In the formula, Be the design variable in the PartA design domain,
Figure BSA00000514255400044
Be the design variable in the PartB design domain, x iDesign variable for the topological optimization definition.
Therefore, the mathematic(al) representation of topological optimization is written as:
Find：X＝(x 1，x 2，...，x n)
Min：Max(σ C) 2.2
C &le; C ( U ) V &le; V ( U ) 0 < x ( L ) &le; x i &le; 1 , i = 1,2 , . . . , n
In the formula, X is a design variable vector, as the pseudo-density of material on the design domain between 0 to 1; C (U)And V (U)The upper limit for deformation energy and volume fraction ratio; Accordingly, x (L)For when unit material is removed, being the lower limit of avoiding the unusual pseudo-density of element stiffness matrix, σ CBe the stress on the shell that under temperature loading, causes by thermal stress.
C is the strain energy of resin mould under well-distributed pressure, and it is the ratio inverse of the rigidity of structure, is written as:
C = 1 2 F P T U P - - - 2.3
In the formula, F PPressure load for the resin mould surface; U PBe the node corresponding motion vector.Constrained parameters are as shown in table 2.
Table 2
(4) find the solution.Carry out the topological optimization iteration, the colophony prototype design result is saved as stl file, directly make colophony prototype with the photocureable rapid shaping machine.Perhaps according to colophony prototype topological optimization size as a result, the reconstruct cad model forms colophony prototype inner chamber configuration, directly makes colophony prototype with the photocureable rapid shaping machine again.Maximum stress Max (σ on the shell C) be 6.217Mpa.
Embodiment 2: adopt the geometric model among the embodiment 1.Temperature and pressure load is constant, changes design constraint deformation energy upper limit C (U)Be 1.3J.Adopt with embodiment 1 identical step and carry out the design of colophony prototype inner chamber, optimize the maximum stress Max (σ on the shell of back C) be 5.932Mpa.
Topological optimization has obtained different optimization results by changing constrained parameters.The contrast of embodiment 1 and embodiment 2 is as shown in table 3.
Table 3
Figure BSA00000514255400051
As can be seen from Table 3, by changing the topological optimization parameter, obtained different optimization configurations and satisfied different designing requirements.For different colophony prototype structures, obtained being applicable to the configuration of this prototype structure by topological optimization.Simultaneously, under the prerequisite that has reduced the shell stress level, considered the rigidity of colophony prototype simultaneously.

Claims (1)

1. colophony prototype inner chamber configuration Optimization Design is characterized in that adopting following steps:
(a) earlier the cad model of colophony prototype is taken out shell, taking out thickness of the shell is 0.2～2mm; Shell model afterwards is inner fills with taking out; The shell that cad model is pumped into is the non-design domain of topological optimization; Model inside is filled to the design domain of topological optimization; Colophony prototype cad model outside surface outwards is offset 6～10mm, and Offset portion forms shell;
(b) geometric model is adopted free grid dividing finite element grid, be defined as PartA; The finite element unit of colophony prototype is wherein duplicated, and displacement is defined as PartB greater than resin mould full-size;
According to the material type of using, define Young modulus, Poisson ratio, the thermal expansivity of type shell material and resin material respectively;
In the shell roasting process, PartA applied 60 ℃ constant temperature field;
Add a well-distributed pressure load at PartB model outside surface;
(c) according to the finite element model of setting up, shell and colophony prototype outer cover unit are non-design domain, and colophony prototype inner chamber unit is a design domain, and the unit of colophony prototype among PartA and the PartB is corresponding one by one, that is:
x i A = x i B = x i ( i = 1,2 . . . n ) - - - 1.1
In the formula,
Figure FSA00000514255300012
Be the design variable in the PartA design domain,
Figure FSA00000514255300013
Be the design variable in the PartB design domain, x iDesign variable for the topological optimization definition;
So the mathematic(al) representation of topological optimization is written as:
Find：X＝(x 1，x 2，...，x n)
Min：Max(σ C) 1.2
C &le; C ( U ) V &le; V ( U ) 0 < x ( L ) &le; x i &le; 1 , i = 1,2 , . . . , n
In the formula, X is a design variable vector, i.e. the pseudo-density of material between 0 to 1 on the design domain; C (U)And V (U)The upper limit for deformation energy and volume fraction ratio; Accordingly, x (L)For when unit material is removed, being the lower limit of avoiding the unusual pseudo-density of element stiffness matrix, σ CBe the stress on the shell that under temperature loading, causes by thermal stress;
C is the strain energy of resin mould under well-distributed pressure, and it is the ratio inverse of the rigidity of structure, is written as:
C = 1 2 F P T U P - - - 1.3
In the formula, F PPressure load for the resin mould surface; U PBe the node corresponding motion vector;
(d) carry out the topological optimization iteration, the colophony prototype design result is saved as stl file, directly make colophony prototype with the photocureable rapid shaping machine; Perhaps according to colophony prototype topological optimization size as a result, the reconstruct cad model forms colophony prototype inner chamber configuration, directly makes colophony prototype with the photocureable rapid shaping machine again.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103440379A (en) * 2013-08-27 2013-12-11 西北工业大学 Optimization design method of fast precision casting resin prototype inner cavity sizes
WO2017128863A1 (en) * 2016-01-26 2017-08-03 机械科学研究总院先进制造技术研究中心 Search algorithm-based optimization method for sand mold employing near net shape forming with digital flexible compression
CN107520407A (en) * 2017-09-29 2017-12-29 东风精密铸造有限公司 A kind of ultra-thin shell hot investment casting combines rod core with decompression type

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102081692A (en) * 2011-01-06 2011-06-01 西北工业大学 Method for keeping design dependence load equivalent in topological optimization

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102081692A (en) * 2011-01-06 2011-06-01 西北工业大学 Method for keeping design dependence load equivalent in topological optimization

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
HAIHUA WU等: "《Rapid casting of turbine blades with abnormal film cooling holes using integral ceramic casting molds》", 《INT J ADV MANUF TECHNOL(2010)》, 31 December 2010 (2010-12-31), pages 13 - 19 *
张建兵，林高用: "《铝合金半连续铸造结晶器内腔形状优化设计》", 《轻合金加工技术》, vol. 33, no. 4, 31 December 2005 (2005-12-31) *
谷小军等: "《面向快速精铸的SL原型内腔构型优化设计》", 《第五届全国快速成形与制造学术会议》, 15 May 2011 (2011-05-15), pages 120 - 125 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103440379A (en) * 2013-08-27 2013-12-11 西北工业大学 Optimization design method of fast precision casting resin prototype inner cavity sizes
CN103440379B (en) * 2013-08-27 2016-09-07 西北工业大学 Rapid Precision Casting colophony prototype inner chamber size optimal design method
WO2017128863A1 (en) * 2016-01-26 2017-08-03 机械科学研究总院先进制造技术研究中心 Search algorithm-based optimization method for sand mold employing near net shape forming with digital flexible compression
CN107520407A (en) * 2017-09-29 2017-12-29 东风精密铸造有限公司 A kind of ultra-thin shell hot investment casting combines rod core with decompression type

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Application publication date: 20110921