CN110142970A - A kind of shell model building method for 3D printing technique - Google Patents
A kind of shell model building method for 3D printing technique Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
- B29C64/30—Auxiliary operations or equipment
- B29C64/386—Data acquisition or data processing for additive manufacturing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y50/00—Data acquisition or data processing for additive manufacturing
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Abstract
A kind of shell model building method for 3D printing technique, comprising: S1 obtains model to be printed and its outer surface parameter R；S2 obtains the shell model i of model to be printed；S3 increases the thickness of preset thickness, and execute step S2 if the yield strength that the maximum stress of shell model i is greater than printed material constrains；Otherwise, step S4 is executed；S4, calculate all vertex shell model i extends out distance, obtains shell model i+1, and judges to extend out whether distance is 0；If the distance that extends out on all vertex shell model i is 0, shell model i is final result shell model；Otherwise, the stress distribution of shell model i+1 is calculated, and executes step S5；S5, if the yield strength that the maximum stress of shell model i+1 is greater than printed material constrains, shell model i is result shell model；Otherwise, the vertex of shell model i+1 is extended out, i is set to i+1, and execute step S4.The non-uniform thickness shell model with minimum volume is constructed, printing cost is greatly reduced.
Description
Technical field
The present invention relates to 3D printing technique field more particularly to a kind of shell model building methods for 3D printing technique.
Background technique
3D printing is one kind based on 3D digital document, with printed materials such as plastics, gypsum, under the control of the computer
It successively prints, the technology of the raw material that are layering construction object.In recent years, 3D printing technique graduallys mature, and in all trades and professions
It is used widely, however printed material is at high price, constrains the further genralrlization of 3D printing technique, with common PLA material
For matter, price is 40 yuan/kilogram, and photosensitive resin is more up to 2000 yuan/kilogram, thus how Optimized model structure, reduce
Print volume is the key that solve printing cost problem.For this purpose, there is scholar to propose to carry out the model space based on stress distribution
Adaptive Voronoi segmentation, obtains Voronoi unit of different sizes, is constructed by emptying Voronoi unit similar to bee
The internal structure of nest, and the inspiration structural type of the axis based on object and skeletal structure, mainly by middle shaft structure, interface frame
And one group of this three parts of connecting rod composition.The studies above achievement reduces the print volume of model, but is by mould
The mode of type internal structure evacuated space structure, there are a large amount of hanging structures for the inside of optimum results model.This class model exists
It is needed when printing using printing technique such as 3DP (3-D spraying bonding), the SLS (precinct laser sintering) without support or is used
Soluble backing material, otherwise printing support are difficult to remove.This improves the hardware threshold of printing and operation to a certain extent
Difficulty.Separately research and propose by detect automatically weakness zone and to model carry out it is internal dig a hole, part thickeies and adds support
These three modes improve the intensity of model, and model adjusted can bear the load that user specifies.This method is according to model
Boundary face and the external force specified of user, optimize thickness parameter according to stress constraint to squeeze out surfaces externally and internally, it is ultimately constructed go out
Meet the shell model of stress constraint.Although the above method can effectively improve mold strength, it can change the surface knot of model
Structure leads to the variation of model appearance, influences usage experience.
Summary of the invention
(1) technical problems to be solved
Based on above-mentioned technical problem, the present invention provides a kind of shell model building methods for 3D printing technique, are based on
The stress distribution of model to be printed constructs the non-uniform thickness shell model with minimum volume, printing cost is greatly reduced；Separately
Outside, any hanging structure is not present inside the shell model of construction, suitable for current all 3 D-printing modes, and house print
Support construction easily removes.
(2) technical solution
The present invention provides a kind of shell model building methods for 3D printing technique, comprising: S1 obtains model to be printed
And its outer surface parameter R；S2 obtains the inner surface parameter S of model to be printed according to preset thicknessi, according to inner surface parameter, outside
Surface parameter R and preset thickness obtain the shell model i of model to be printed；S3, if the maximum stress of shell model i is greater than printing material
The yield strength of material constrains, then increases the thickness of preset thickness, and execute step S2；If the maximum stress of shell model i be less than or
Yield strength equal to printed material constrains, and thens follow the steps S4；S4, calculate all vertex shell model i extends out distance, obtains
Shell model i+1, and judge to extend out whether distance is 0；If the distance that extends out on all vertex shell model i is 0, shell model i is
For final result shell model；Otherwise, the stress distribution of shell model i+1 is calculated, and executes step S5；S5, if shell model i+1 is most
The yield strength that big stress is greater than printed material constrains, then shell model i is result shell model；Otherwise, in shell model i+1
Surface is that starting point extends out the vertex of shell model i+1, i is set to i+1, and execute step S4.
Optionally, all vertex shell model i are calculated in step S4 extends out distance specifically: according to the stress of shell model i
The distributed intelligence calculating all vertex shell model i extend out distance.
Optionally, distance d is extended outvCalculation formula are as follows:
Wherein, doFor vertex v to the distance of shell model outer surface, σvFor the stress value at vertex v, σyFor printed material
Yield strength, tminFor the minimum print thickness of printer, s1For the safety coefficient of yield strength, s2For the peace of minimum print thickness
Overall coefficient.
Optionally, the inner surface parameter S of model to be printed is obtained in step S2 according to preset thicknessiSpecifically: use base
The inner surface parameter S of model to be printed is obtained in the isosurface extraction algorithm that model voxelization indicatesi。
Optionally, step S2 is specifically included: S21, using preset length as side length, by the axis where model outer surface to be printed
It is aligned bounding box voxelization, obtains a group of voxels；S22, judge in group of voxels that each voxel is relative to the model to be printed outside
The position on surface；S23, using the outer surface of model outer surface to be printed as boundary, construct each voxel in group of voxels first has
To distance field, wherein the distance value outside model outer surface to be printed is negative, the distance inside model outer surface to be printed
Value is positive；S24, A times with preset length is side length, repeats step S21~S23, to construct the second Signed Distance Field,
In, 0 < A < 1；S25, obtaining distance value in the first Signed Distance Field is one layer of voxel of preset thickness/preset length；S26 is obtained
Take distance value of eight vertex of each voxel in one layer of voxel obtained in step S25 in the second Signed Distance Field；
The contour surface of distance value in S27, extraction step S26.
Optionally, step S27 specifically: according to the distance value in Marching Cubes algorithm extraction step S26 etc.
Value face.
Optionally, 0.25 A.
Optionally, step S21 is specifically included: S211, and B times with preset length is side length, by model outer surface to be printed
The axis aligned bounding box voxelization at place, obtains a big group of voxels, and B is the integer greater than 1；S212, by big group of voxels with to
The voxel of printer model outer surface intersection will intersect in big group of voxels with model outer surface to be printed using preset length as side length
The further voxelization of voxel, obtain a group of voxels.
Optionally, the stress distribution of shell model i or shell model i+1 is calculated using von Mises equivalent stress.
Optionally, the stress distribution of shell model i or shell model i+1 is obtained using following steps: by shell model i or shell model
I+1 gridding obtains corresponding grid model parameter；Grid model parameter is imported in static analysis software；Corresponding side is set
Boundary's condition, boundary condition include at least suffered external force, material properties, fixed position；Grid model parameter is carried out based on limited
The static analysis of member obtains stress distribution.
(3) beneficial effect
The present invention provides a kind of shell model building method for 3D printing technique, the stress based on model to be printed point
Cloth is constructed in the case where not changing model appearance to be printed, meeting given applied stress constraint with the non-homogeneous of minimum volume
Printing cost is greatly reduced in thickness shell model；In addition, any hanging structure is not present inside the shell model of construction, suitable for working as
Preceding all 3 D-printing modes, and house print support construction easily removes.
Detailed description of the invention
Fig. 1 diagrammatically illustrates the shell model building method block diagram for being used to save material 3D printing of the embodiment of the present disclosure；
Fig. 2 diagrammatically illustrates the shell model building method detailed process for being used to save material 3D printing of the embodiment of the present disclosure
Figure；
Fig. 3 A diagrammatically illustrates the model entity schematic diagram of the model of a model to be printed of the embodiment of the present disclosure；
Fig. 3 B diagrammatically illustrates the first directed distance of the corresponding model entity to be printed of Fig. 3 A of the embodiment of the present disclosure
Field indicates figure；
Fig. 3 C diagrammatically illustrates the contour surface schematic diagram of the corresponding model entity to be printed of Fig. 3 A of the embodiment of the present disclosure；
Fig. 3 D diagrammatically illustrates the shell model schematic diagram of the corresponding model entity to be printed of Fig. 3 A of the embodiment of the present disclosure；
Fig. 4 A diagrammatically illustrates the shell model inner surface vertex schematic diagram of the model entity to be printed of the embodiment of the present disclosure；
Fig. 4 B diagrammatically illustrates expansion outside the shell model inner surface vertex of the model entity to be printed of the embodiment of the present disclosure
From schematic diagram；
What Fig. 4 C diagrammatically illustrated the embodiment of the present disclosure extends out the result schematic diagram after distance is extended out by Fig. 4 B；
Fig. 5 A diagrammatically illustrates the model entity schematic diagram of the model of another model to be printed of the embodiment of the present disclosure；
Fig. 5 B diagrammatically illustrate the embodiment of the present disclosure Fig. 5 A model it is corresponding meet yield strength constraint it is initial
Uniform thickness shell model；
Fig. 5 B that Fig. 5 C diagrammatically illustrates the embodiment of the present disclosure extended out three times after shell model；
Fig. 5 B that Fig. 5 D diagrammatically illustrates the embodiment of the present disclosure carries out the shell model after extending out five times.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with specific embodiment, and reference
Attached drawing, the present invention is described in more detail.
The present invention provides a kind of for saving the shell model building method of material 3D printing.Input is to be printed solid for one
Three-dimensional grid model, printed material m apply load F, minimum print thickness tmin.We assume that model is permissible in solid situation
The load is born, i.e., the maximum stress of model is less than yield strength at this time；Otherwise, it can not generate and be able to bear the load without producing
The shell model of raw yield phenomenon, without necessity of shell model construction.Meet model appearance it is constant, load F effect under do not send out
The minimum thickness t of raw surrender and shell modelmNot low and minimum print thickness tminIn the case where, the volume of Optimized model is drawn
Enter yield strength safety coefficient s1, minimum print thickness safety coefficient s2Objective optimization function afterwards:
min Vol(M)
s.t.σmax≤s1σy,
tm≥s2tmin
Wherein, first constraint condition is yield strength constraint condition, for guaranteeing that model can carry specified load
Without destroying；Second constraint condition is minimum print thickness constraint condition, and the minimum thickness for guaranteeing model is not low
In the minimum print thickness of printer, s2For the safety coefficient of minimum print thickness, brought for eliminating printer printing error
Influence.Specific configuration method is as follows.
A kind of shell model building method for 3D printing technique, referring to Fig. 1 and Fig. 2, method includes: S1, is obtained wait beat
Stamp type and its outer surface parameter R；S2 obtains the inner surface parameter S of model to be printed according to preset thicknessi, according to inner surface
Parameter, outer surface parameter R and thickness obtain the shell model i of model to be printed；S3 is beaten if the maximum stress of shell model i is greater than
The yield strength constraint for printing material, then increase the thickness of preset thickness, and execute step S2；If the maximum stress of shell model i is small
In or equal to printed material yield strength constraint, then follow the steps S4；S4, calculate all vertex shell model i extends out distance,
Shell model i+1 is obtained, and judges to extend out whether distance is 0；Shell model i if distance is 0 is extended out if all vertex shell model i
As final result shell model；Otherwise, the stress distribution of shell model i+1 is calculated, and executes step S5；S5, if shell model i+1
The yield strength that maximum stress is greater than printed material constrains, then shell model i is result shell model；Otherwise, with shell model i+1's
Inner surface is that starting point extends out the vertex of shell model i+1, i is set to i+1, and execute step S4.The embodiment of the present invention is first
First need to construct the shell model of a uniform thickness, then the stress distribution based on shell model adaptively extends out inner surface vertex, obtains
Objective function must be allowed to obtain the shell model of minimum, further decrease the volume of shell model, to reduce needed for printing shell model
Printed material will describe to this method in detail by taking specific embodiment as an example below.
S1 obtains model to be printed and its outer surface parameter R；
It is modeled specifically, treating printer model, obtains the model of model to be printed, as shown in Figure 3A, and its it is outer
Surface parameter R.Firstly the need of the shell model of one uniform preset thickness t of building, step S2 specific as follows.
S2 obtains the inner surface parameter S of model to be printed according to preset thicknessi, according to inner surface parameter, outer surface parameter
R and preset thickness obtain the shell model i of model to be printed；
Specifically, step S2 is specifically included:
S21, by the axis aligned bounding box voxelization where model outer surface to be printed, is obtained using preset length as side length
One group of voxels；
Specifically, step S21 is specifically included:
S211, B times with preset length is side length, by the axis aligned bounding box voxel where model outer surface to be printed
Change, obtain a big group of voxels, B is the integer greater than 1；
When selecting preset length a, tend not to select suitable preset length when initial, therefore can be using by thick
It is refined step by step to thin selection method, it is 2 times of preset length a that vacation, which the side length not selected, first, will be outside model to be printed
Axis aligned bounding box voxelization where the R of surface obtains a big group of voxels VOXEL.
S212, the voxel that will intersect in big group of voxels with model outer surface to be printed will substantially using preset length as side length
The further voxelization of voxel intersected in plain group with model outer surface to be printed, obtains a group of voxels.
Judge position of each voxel VOX relative to model outer surface R to be printed in big group of voxels VOXEL, then by
8 side lengths that VOX outside the R of printer model outer surface is segmented out are the small voxel vox of a centainly also in model outer surface to be printed
The outside of R, the small voxel vox that 8 side lengths segmented out by the VOX inside model outer surface R to be printed are a centainly also to
The inside of printer model outer surface R, the voxel VOX that will intersect in big group of voxels with model outer surface to be printed, with preset length a
For side length, the further voxelization of voxel that will intersect in big group of voxels with model outer surface R to be printed obtains a group of voxels
voxel。
S22 judges position of each voxel relative to model outer surface to be printed in group of voxels；
Judge position of each voxel v ox relative to model outer surface R to be printed in group of voxels voxel, that is, determines the body
Plain vox is outside model outer surface R to be printed, internal or intersection.
S23, using the outer surface of model outer surface to be printed as boundary, construct group of voxels in each voxel first it is oriented away from
It leaves the theatre, wherein the distance value outside model outer surface to be printed is negative, and the distance value inside model outer surface to be printed is
Just；
Using the outer surface R of model outer surface to be printed as boundary, first of each voxel v ox in group of voxels voxel is constructed
Signed Distance Field Dc, as shown in Figure 3B, as the first Signed Distance Field DcThe section of expression, wherein in model outer surface to be printed
Distance value outside R is negative, and the distance value inside model outer surface R to be printed is positive.
S24, A times with preset length is side length, repeats step S21~S23, to construct the second Signed Distance Field,
Wherein, 0 < A < 1；
Further above-mentioned group of voxels voxel is further refined for side length with 0.25 times of preset length, constructs fine granularity
The second Signed Distance Field Df。
S25, obtaining distance value in the first Signed Distance Field is one layer of voxel of preset thickness/preset length；
Obtain the first Signed Distance Field DcMiddle distance value is one layer of voxel v oxel of t/ac。
Eight vertex of each voxel in one layer of voxel obtained in S26, obtaining step S25 are in the second Signed Distance Field
In distance value；
To in voxel v oxelcIn voxel v oxc, obtain voxel v oxc8 vertex in distance field DfIn distance value.
The contour surface of distance value in S27, extraction step S26.
Using the contour surface S (as shown in Figure 3 C) of the distance value in Marching Cubes algorithm extraction step S26, then S
The shell model (S, R) (as shown in Figure 3D) with a thickness of t is surrounded with R, exports S.
The shell model i of the model to be printed with preset thickness t can be acquired by above-mentioned steps S21~S27, parameterized
It is expressed as (Si, R).
S3 increases the thickness of preset thickness if the yield strength that the maximum stress of shell model i is greater than printed material constrains
Degree, and execute step S2；If the yield strength that the maximum stress of shell model i is less than or equal to printed material constrains, step is executed
Rapid S4；
Calculate shell model i (Si, R) stress distribution, if shell model i (Si, R) maximum stress be greater than printed material bend
Strength constraint is taken, then increases the thickness of preset thickness, i.e. t=t+ δ t, and repeat step S2；If shell model i (Si, R)
The yield strength that maximum stress is less than or equal to printed material constrains, and thens follow the steps S4.
S4, calculate all vertex shell model i extends out distance, obtains shell model i+1 (Si+1, R), and judge to extend out distance
It whether is 0；If the shell model i if distance is 0 that extends out on all vertex shell model i be final result shell model；Otherwise, it calculates
The stress distribution of shell model i+1, and execute step S5；
According to shell model i (Si, R) stress distribution determine all vertex extend out distance dvExtend out distance dvCalculating it is public
Formula are as follows:
Wherein, doFor vertex v to the distance of shell model outer surface, σvFor the stress value at vertex v, σyFor printed material
Yield strength, tminFor the minimum print thickness of printer, S1For the safety coefficient of yield strength, s2For the peace of minimum print thickness
Overall coefficient.First item in formula is used to guarantee minimum print thickness constraint, and Section 2 is used to calculate vertex in current stress feelings
Distance is extended out under condition, indicates the maximum distance extended out every time.It is smaller that formula has the biggish vertex of inner surface upper stress
Extend out distance, the lesser vertex of stress, which has, biggish extends out distance.
As shown in Figure 4 A, vertex a, b, c, d are obtained with its corresponding extends out after distance dv is extended out (as shown in Figure 4 B)
To shell model i+1 (Si+1, R) and (as shown in Figure 4 C), and judge to extend out whether distance is 0；If shell model i (Si, R) and (such as Fig. 4 A institute
Show) distance that extends out on all vertex is 0, then and shell model i is final result shell model；Otherwise, shell model i+1 is calculated
(Si+1, R) stress distribution, and execute step S5.
S5, if the yield strength that the maximum stress of shell model i+1 is greater than printed material constrains, shell model i is result
Shell model；Otherwise, it is extended out by vertex of the starting point to shell model i+1 of the inner surface of shell model i+1, i is set to i+1, and
Execute step S4.
If shell model i+1 (Si+1, R) maximum stress be greater than printed material yield strength constrain, then shell model i is
As a result shell model；Otherwise, with shell model i+1 (Si+1, R) inner surface Si+1It is starting point to shell model i+1 (Si+1, R) vertex into
Row calculates normal direction n along itvIt is displaced outwardly dvDistance extends out, and i is set to i+1, and execute step S4, calculates shell model i+1 institute
Have vertex extends out distance, obtains shell model i+2 (Si+2, R), and judge to extend out whether distance is 0；If all tops shell model i+1
The distance that extends out of point be 0 shell model i+1 is final result shell model；Otherwise, the stress distribution of shell model i+2 is calculated,
And execute step S5 ... ....Successively mode is extended out step by step, until output result shell model.
The calculating of the stress distribution of shell model involved in above-mentioned steps S3 and S4, can be using ansys, SolidWorks etc.
Analysis software carries out numerical value calculating, the Simulation work of the preferred Machine Design software SolidWorks of the embodiment of the present invention to it
Tool packet carries out the static analysis based on finite element, specifically comprises the following steps:
Shell model i or shell model i+1 gridding are obtained into corresponding grid model parameter；
Grid in the embodiment of the present invention is preferably tetrahedral grid.
Grid model parameter is imported in static analysis software；
Above-mentioned tetrahedral grid is imported in SolidWorks.
Corresponding boundary condition is set, and boundary condition includes at least suffered external force, material properties, fixed position；
Static analysis based on finite element is carried out to the grid model parameter, obtains stress distribution.
Static analysis based on finite element is carried out to the model after tetrahedralization, obtains von Mises equivalent stress distribution
Situation.
Yield strength in the embodiment of the present invention constrains σmax≤s1σy, fourth intensity of this constraint condition according to the mechanics of materials
Theoretical installation, i.e. the maximum value σ when the von Mises equivalent stress of component all sitesmaxReach the yield strength σ of materialy
When, material starts to surrender, and plastic deformation occurs, can not also revert to original shape after external force revocation.s1For yield strength
Safety coefficient is used to give building necessary margin of safety.Here von Mises equivalent stress is calculated by following formula:
Wherein, σmaxFor the maximum value of von Mises equivalent stress in "current" model, σyFor the physics of printed material used
Attribute yield strength, s1For the safety coefficient no more than 1, σ1、σ2、σ3Orthogonal three directions bends respectively in space
Take intensity.
In another embodiment, 6.5 × 10 × 6cm of bounding box size of model to be printed is inputted3Kitten model, 3D beats
Print machine minimum print thickness is 1mm, load 1000N, printed material PLA, and relational physical properties are Young's modulus
3500MPa, Poisson's ratio 0.36, yield strength 70MPa.Related coefficient are as follows: s1=0.7, s2=1.2, p=0.002.
Fig. 5 A is the section for inputting solid model to be printed；
Fig. 5 B is the initial uniform thickness shell model (S for meeting yield strength and constraining constructed by step S1~S20, R), lead to
Numerical simulation is crossed it can be concluded that shell model (S0, R) stress distribution situation, it is larger in the neck and leg-stress of the model；
Fig. 5 C is the shell model (S extended out three times by step S4~S5 to mold inner surfaces3, R)；
Fig. 5 D is to carry out five shell model (S extended out to mold inner surfaces by step S4~S55, R), it can be seen that
The neck of shell model after extending out for 5th time and leg are thicker, meet and implement needs.
It extends out to obtain shell model (S due to the 6th time6, R) maximum stress σmaxGreater than yield strength constraint condition s1σy, therefore
(S5, R) and it is exactly the final optimization pass of the printer model as a result, being computed the result shell model exported using building method of the invention
Volume is input solid model volume 22.4%.
In conclusion provided by the present invention for the shell model building method of 3D printing technique, based on model to be printed
Stress distribution is constructed in the case where not changing model appearance to be printed, meeting given applied stress constraint with minimum volume
Printing cost is greatly reduced in non-uniform thickness shell model；In addition, any hanging structure is not present inside the shell model of construction, fit
For current all 3 D-printing modes, and house print support construction easily removes.
Particular embodiments described above has carried out further in detail the purpose of the present invention, technical scheme and beneficial effects
It describes in detail bright, it should be understood that the above is only a specific embodiment of the present invention, is not intended to restrict the invention, it is all
Within the spirit and principles in the present invention, any modification, equivalent substitution, improvement and etc. done should be included in guarantor of the invention
Within the scope of shield.
Claims (10)
1. a kind of shell model building method for 3D printing technique, comprising:
S1 obtains model to be printed and its outer surface parameter R；
S2 obtains the inner surface parameter S of the model to be printed according to preset thicknessi, according to the inner surface parameter, outer surface
Parameter R and preset thickness obtain the shell model i of the model to be printed；
S3 increases the preset thickness if the yield strength that the maximum stress of the shell model i is greater than printed material constrains
Thickness, and execute step S2；If the yield strength that the maximum stress of the shell model i is less than or equal to printed material constrains,
Execute step S4；
S4, calculate all vertex shell model i extends out distance, obtains shell model i+1, and whether extend out distance described in judgement
It is 0；If the distance that extends out on all vertex shell model i is 0, the shell model i is final result shell model；It is no
Then, the stress distribution of shell model i+1 is calculated, and executes step S5；
S5, if the yield strength that the maximum stress of shell model i+1 is greater than printed material constrains, shell model i is result shell mold
Type；Otherwise, it is extended out by vertex of the starting point to shell model i+1 of the inner surface of shell model i+1, i is set to i+1, and execute
Step S4.
2. shell model building method according to claim 1, the calculating all tops shell model i described in the step S4
Point extends out distance specifically:
Distance is extended out according to what the stress distribution information of the shell model i calculated all vertex shell model i.
3. shell model building method according to claim 2, described to extend out distance dvCalculation formula are as follows:
Wherein, doFor vertex v to the distance of shell model outer surface, σvFor the stress value at vertex v, σyFor the surrender of printed material
Intensity, tminFor the minimum print thickness of printer, s1For the safety coefficient of yield strength, s2For the safety system of minimum print thickness
Number.
4. shell model building method according to claim 1, described wait beat according to preset thickness acquisition described in step S2
The inner surface parameter S of stamp typeiSpecifically:
The inner surface parameter S of the model to be printed is obtained using the isosurface extraction algorithm indicated based on model voxelizationi。
5. shell model building method according to claim 4, the step S2 is specifically included:
S21, by the axis aligned bounding box voxelization where the model outer surface to be printed, is obtained using preset length as side length
One group of voxels；
S22 judges position of each voxel relative to the model outer surface to be printed in the group of voxels；
S23, using the outer surface of the model outer surface to be printed as boundary, construct each voxel in the group of voxels first has
To distance field, wherein the distance value outside the model outer surface to be printed is negative, in the model outer surface to be printed
The distance value in portion is positive；
S24, A times with preset length is side length, repeats step S21~S23, to construct the second Signed Distance Field, wherein
0 < A < 1；
S25, obtaining distance value in first Signed Distance Field is one layer of voxel of preset thickness/preset length；
S26, obtain eight vertex of each voxel in one layer of voxel obtained in the step S25 described second it is oriented away from
Distance value in leaving the theatre；
The contour surface of distance value in S27, extraction step S26.
6. shell model building method according to claim 5, step S27 specifically:
According to the contour surface of the distance value in Marching Cubes algorithm extraction step S26.
7. shell model building method according to claim 5, the A is 0.25.
8. shell model building method according to claim 5, the step S21 is specific further include:
S211, B times with preset length is side length, by the axis aligned bounding box voxel where the model outer surface to be printed
Change, obtain a big group of voxels, B is the integer greater than 1；
S212, the voxel that will intersect in the big group of voxels with the model outer surface to be printed will using preset length as side length
The further voxelization of voxel intersected in the big group of voxels with the model outer surface to be printed, obtains a group of voxels.
9. shell model building method according to claim 1 calculates the shell model i using von Mises equivalent stress
Or the stress distribution of shell model i+1.
10. shell model building method according to claim 1 obtains the shell model i or shell model i using following steps
+ 1 stress distribution:
The shell model i or shell model i+1 gridding are obtained into corresponding grid model parameter；
The grid model parameter is imported in static analysis software；
Corresponding boundary condition is set, and the boundary condition includes at least suffered external force, material properties, fixed position；
Static analysis based on finite element is carried out to the grid model parameter, obtains stress distribution.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6409902B1 (en) * | 1999-08-06 | 2002-06-25 | New Jersey Institute Of Technology | Rapid production of engineering tools and hollow bodies by integration of electroforming and solid freeform fabrication |
| US20150048209A1 (en) * | 2013-08-16 | 2015-02-19 | Robert Hoyt | Structures with Internal Microstructures to Provide Multifunctional Capabilities |
| CN108247049A (en) * | 2017-12-21 | 2018-07-06 | 西安欧中材料科技有限公司 | A kind of selective laser increasing material manufacturing method using CoCrMo alloy powders |
| CN108921928A (en) * | 2018-07-12 | 2018-11-30 | 上海昕健医疗技术有限公司 | Voxelization processing method and its device based on triangle grid model |
-
2019
- 2019-05-23 CN CN201910437163.9A patent/CN110142970B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6409902B1 (en) * | 1999-08-06 | 2002-06-25 | New Jersey Institute Of Technology | Rapid production of engineering tools and hollow bodies by integration of electroforming and solid freeform fabrication |
| US20150048209A1 (en) * | 2013-08-16 | 2015-02-19 | Robert Hoyt | Structures with Internal Microstructures to Provide Multifunctional Capabilities |
| CN108247049A (en) * | 2017-12-21 | 2018-07-06 | 西安欧中材料科技有限公司 | A kind of selective laser increasing material manufacturing method using CoCrMo alloy powders |
| CN108921928A (en) * | 2018-07-12 | 2018-11-30 | 上海昕健医疗技术有限公司 | Voxelization processing method and its device based on triangle grid model |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102021124013B4 (en) | 2021-09-16 | 2023-08-17 | Hyperganic Group GmbH | Computer-implemented method for creating a second voxel model from a first voxel model |
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