Research Article Optimization of Process Parameters of Stamping …downloads.hindawi.com/journals/jam/2014/470320.pdf · 2019-07-31 · Research Article Optimization of Process Parameters

Research ArticleOptimization of Process Parameters of Stamping Forming ofthe Automotive Lower Floor Board

Guoying Ma and Binbing Huang

College of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao 266590 China

Correspondence should be addressed to Binbing Huang kinghuang1990163com

Received 19 May 2014 Revised 4 August 2014 Accepted 7 August 2014 Published 18 August 2014

Academic Editor Ricardo Perera

Copyright copy 2014 G Ma and B HuangThis is an open access article distributed under the Creative CommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

There are many process parameters which have great effect on the forming quality of parts during automobile panel stampingforming process This paper took automotive lower floor board as the research object the forming process was analyzed by finiteelement simulation usingDynaformThe influences of fourmain process parameters including BHF (blank holder force) die cornerradius friction coefficient and die clearance on the maximum thinning rate and the maximum thickening rate were researchedbased on orthogonal experimentThe results show that the influences of each value of various factors on the target are not identicalOn this basis the optimization of the four parameters was carried out and the high quality product was obtained and themaximumthinning rate and maximum thickening rate were effectively controlled The results also show that the simulation analysis providesthe basis for the optimization of the forming process parameters and it can greatly shorten the die manufacturing cycles reducethe production costs and improve the production efficiency

1 Introduction

Automotive lower floor board has an important effect on thetransportation process of vehicle the performance of lowerfloor determines the stability and safety of the whole vehicle[1 2] Automobile lower floor engine cover driving cab andvarious special-shaped surface and the internal sheet partsof the body all belong to the automotive panels Automobilepanel is generally composed of the space free curved surfaceand the production of it is a process of multistep and mul-tiprocess due to its complex shape small relative thicknesslarge size and high surface quality requirementsThe formingprocesses of automobile covering parts generally includedrawing trimming stamping shaping flanging and otherprocesses of which the stamping process is the most impor-tant step of all and the results of the stamping are directlyrelated to the product quality and subsequent process Inorder to get qualified stamping automotive panel tomeet cus-tomer requirementsmultiplemodifying and repeated debug-ging are required for stamping die stamping process tech-nological parameters and so forth while ldquotrial and errorrdquomethod is used in the traditional way for repeated testing

which not only require a longer production cycle but alsorequire high production costs

With the continuous development of numerical analysistechnology plastic forming theory stamping technology andcomputer technology CAE (computer aided engineering)technology is gradually applied in stamping process and diedesign process for automotive panels [3 4] CAE related soft-ware are more and more widely used in panel die debuggingprocess The formability and possible defects of parts can beanalyzed through the simulation which provide the reliablebasis for die debugging so that it can reduce the diemanufac-turing problems shorten the production cycle save produc-tion costs and offer more economic benefits for enterprises[5 6]

In the stamping forming process of automotive panelsmany process parameters have important influence on thequality of forming parts and many scholars have done manystudies in the optimization of process parameters [7ndash10]In order to study the effects of several process parameterswhich have great influence on the forming quality of partswhich can be optimized this paper adopts automotive lowerfloor board as the research object Under the draw bead

Hindawi Publishing CorporationJournal of Applied MathematicsVolume 2014 Article ID 470320 9 pageshttpdxdoiorg1011552014470320

2 Journal of Applied Mathematics

Establish 3D model of partusing ProE

Import the 3D model into Dynaform

Mesh the part and check the model

Blank size estimate and mesh the blank model

Copy and offset the die model andseparate the binder and punch

Define tools position

Set the process parameters

Submit and solve the job

Postprocess and analyze the result

Figure 1 Flowchart of the process simulation

distribution the shape and parameters remain unchangeduse the orthogonal experiment and ETA (engineering tech-nology associates)Dynaform simulation software to analyzeBHF (blank holder force) die corner radius die clearanceand friction coefficient to study impact level of these fourparameters with the results of maximum thinning rate andmaximum thickening rate and optimize these parameters

2 Establishment of Simulation Analysis Model

The simulation process of stamping forming mainly includesthe establishment of 3D model and finite element modelsdefining the forming tools setting the process parametersand analyzing the results The flowchart of the processsimulation is shown in Figure 1

21 Establishment of 3D Model of Part Automotive LowerFloor Board According to the requirements of the analysisdraw three-dimensional model of automotive lower floorboard parts by using ProE firstly Analysis of the partsstructure shows that the parts have large transverse size smalllongitudinal size large drawing depth and complex shapesso final shape should be finished go through drawing rarrtrimming rarr punching rarr shaping rarr flanging rarr lateralpunching rarr trimming and other processes Depending onthe actual production experience the cracking usually occursat the lower portion of both ends of the parts the flat endsand the mid plane may produce insufficient forming On thebasis of the defects the parts may arise necessary process

Figure 2 Drawing die model (die)

Die

Punch

Binder

Blank

Figure 3 The FE model of automotive lower floor board

supplement and binder surface shape design are required toreduce defects in the process of parts stamping Drawing diemodel is shown in Figure 2 the part is defined as die and usedas the forming tool during the simulation and the model issaved as igs format for subsequent finite element modeling

22 Establishment of Finite Element Models Dynaform soft-ware has a total of 16 element types currently the mostcommonly used are Huhges-Liu (HL) shell element andBelytschko-Tsay (BT) shell element and these two elementsare constructed based on the Mindlin plate theory with theadvantages of fast calculation speed and high simulationaccuracy [11] The default element type is Belytschko-Tsayshell element in Dynaform software which is the mostefficient element in explicit algorithm In this paper thedie and sheet metal are meshed by using BT shell elementComprehensively considering simulation accuracy and com-putation time sheetmesh size 12mmand adaptive grade 4 areaccepted And the finite element model of automotive lowerfloor board is shown in Figure 3 In order to ensure the overallforming quality of parts draw bead distribution shape andparameters remain unchangedThe sheet metal use stampingsteel WSS-M-1A365A12 the mechanical properties of thematerials are given in Table 1 and the plate thickness is07mmThe plate is located on binder the constitutivemodelof sheet material applied in this paper is the three parameters

Journal of Applied Mathematics 3

Table 1 Mechanical property parameters of WSS-M-1A365A12 steel sheet

Mass density(kgsdotmmminus3) Youngrsquos modulusMPa Hardening rule Strength coefficient KMPa Poisson ratio Lankford param 1198770 45 90

785 times 10minus3 21 times 105 0225 5868 03 135 115 165

Barlat-Lian thick anisotropic yield criterion [12] the criterionis

119891 = 119886

10038161003816100381610038161198701

+ 1198702

1003816100381610038161003816

119898

+ 119886

10038161003816100381610038161198701

minus 1198702

1003816100381610038161003816

119898

+ 119888

100381610038161003816100381621198702

1003816100381610038161003816

119898

= 2120590

119898

(1)

where1198701

= (120590119909119909

+ℎ120590119910119910

)21198702

= radic((120590119909119909

minus ℎ120590119910119910

)2)2

+ 1199022

1205902

119909119910

120590 is equivalent to yield stress 120590

119909

is sheet stress along therolling direction 120590

119910

is sheet stress vertical to the rollingdirection 119886 119888 ℎ and 119902 are the coefficient of material plasticanisotropy and 119898 is Barlat-Lian index related to the crystalstructure

3 Orthogonal Experiment Design

Orthogonal experiment is a design method to study multiplefactors level which is often used for the performance predic-tion of stamping forming of automotive panels [13ndash16] Dur-ing the process of automotive lower floor board stamping themain process parameters affecting the forming performanceinclude BHF die corner radius die clearance and frictioncoefficient For the above process parameters orthogonalexperiment factors were designed for the BHF (factor 119860)die corner radius (factor 119861) die clearance (factor 119862) andfriction coefficient (factor 119863) The maximum thinning rateand maximum thickening rate are evaluation index and themaximum thinning rate Δ is as follows

Δ = max(1199050

minus 119905119894

1199050

times 100) (2)

where 1199050

is the thickness of the sheet before drawing and 119905119894

isthe thickness of unit 119894 of sheet metal after drawing

Change (1199050

minus 119905119894

) in formula (2) into (119905119894

minus 1199050

) for maximumthickness ratio and maximum thinning rate and maximumthickening rate of products should be as small as possibleduring the optimization in order to ensure product strength

BHF is the force on the blank holder in drawing processit can be used to solve the wrinkling problem in the processof drawing and it can be calculated by the following formula

119876 = 119865119902 (3)

where 119865 is the area of the pressure side (mm2) 119902 is for unitBHF (MPa) and its value is determined by experiment unitBHF of different materials is selected according to Table 53in [17] From formula (3) the value of BHF was calculatedto be about 500 kN and the three levels of experiments werechosen for 400 kN 500 kN and 600 kN

There is virtually no effect of the punch speed on theforming performance [18] we took the punch speed as3000mms during all the simulation The die corner radius

Table 2 Factors and levels of orthogonal experiment

Level

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 500 6 11119905 0123 600 9 12119905 014

Table 3 Scheme of orthogonal experiment

Number

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 400 6 11119905 0123 400 9 12119905 0144 500 3 11119905 0145 500 6 12119905 0106 500 9 10119905 0127 600 3 12119905 0128 600 6 10119905 0149 600 9 11119905 010

can affect the stamping process and we took 3mm 6mmand 9mm for the experiment Die clearances were 10119905 11119905and 12119905 with 119905 as sheet metal thickness We set frictioncoefficient as 010 012 and 014 for the experiment Theabove factors were listed in Table 2 combination schemes oforthogonal experiment process parameters were designed byusing orthogonal array L

9

(34) as shown in Table 3

4 Results and Analysis ofOrthogonal Experiment

Due to the large number of experiment data not all simula-tion results can be displayed only the simulation results ofprocess parameters scheme through the orthogonal experi-mental design corresponding to maximum thinning rate andmaximum thickening rate were counted in Table 4

From the simulation results in Table 4 it can be seenthat the maximum thinning rate of most experiment parts


Table 4 Thickness reduction and thinness reduction data obtained by orthogonal experiment

Number Factors Evaluation index119860 119861 119862 119863 Maximum thinning rate Maximum thickening rate

1 1198601 1198611 1198621 1198631 3087 6272 1198601 1198612 1198622 1198632 2914 6813 1198601 1198613 1198623 1198633 2863 5874 1198602 1198611 1198622 1198633 3631 5025 1198602 1198612 1198623 1198631 2916 6536 1198602 1198613 1198621 1198632 2907 5537 1198603 1198611 1198623 1198632 3256 5068 1198603 1198612 1198621 1198633 3587 4989 1198603 1198613 1198622 1198631 2944 532

Table 5 Range analysis of thickness reduction and thinness reduction data

Factors Maximum thinning rate Maximum thickening rate119860 119861 119862 119863 119860 119861 119862 119863

1198701198941

8864 9974 9581 8947 1895 1635 1678 18121198701198942

9454 9417 9489 9077 1708 1805 1715 17401198701198943

9787 8714 9035 10081 1536 1672 1746 15871198961198941

2955 3325 3194 2982 632 545 559 6041198961198942

3151 3139 3163 3026 569 611 572 5801198961198943

3262 2905 3012 3360 512 557 582 529119877 308 420 182 378 120 066 023 075Optimal levels 1198601 1198613 1198623 1198631 1198603 1198611 1198621 1198633

Primary and secondary order 119861 gt 119863 gt 119860 gt 119862 119860 gt 119863 gt 119861 gt 119862

Optimal combination 1198601119861311986231198631 1198603119861111986211198633

is below 30 In general the reqkuirement of maximumthinning rate is not more than 30 while some parts of theautomotive lower floor board thinning rate has exceeded themaximum value so that the part has a very large risk ofcracking maximum thickening rate for all parts of the exper-iment program is between 4 and 7 there are small gapsamong the results of each experiment scheme the maximumthickening region is mainly in binder surface which has alarge risk of wrinkling There are two common methods forsolving wrinkling of the binder surface one is to increase theBHF and one is to reduce the intensity of drawbeads andthe degree of solving wrinkling should be in accordance withcustomer requirementsThe analysis results of the maximumthinning rate and maximum thickening rate are shown inTable 5 with 119870

1198941

1198701198942

and 1198701198943

respectively correspondingto the sum of 1 2 and 3 level of 119894 (119894 = 119860 119861 119862119863) factors1198961198941

1198961198942

and 1198961198943

respectively corresponding to the averagevalue of 1 2 and 3 level of 119894 (119894 = 119860 119861 119862119863) factors and119877 stands for range corresponding to each factor The rangein Table 5 represents the influence degree of various factorson the results It can be seen that the range values of eachfactor are not equal which indicates that the factors havedifferent impacts on forming performance of automotivelower floor board The relationship between the maximum

thinning rate and experimental factors is shown in Figure 4and the relationship between the maximum thickening rateand experimental factors is shown in Figure 5

We can see clearly from the relationship shown in Figures4 and 5 that the change trend of the maximum thinningrate and the maximum thickening is almost in the oppositecondition with the experimental factors The maximumthinning rate of automotive lower floor board increases alongwith the increases of BHF the maximum thickening ratedecreases along with the increases of BHF So the large BHFcan avoid the wrinkle and also may lead to the risk ofcracking The influence of friction coefficient is the same asBHF The maximum thinning rate decreases along with theincreases of die corner radius and the maximum thickeningrate increases first and decreases then alongwith the increasesof die corner radius The influence of die clearance is minoron these two evaluation indexes

5 Optimization Schemesand Simulation Results

Due to some parts of automotive lower floor board higherthinning exists during stamping process these areas would


15

20

25

30

35

40

45

300 400 500 600 700 0 3 6 9 12

063 07 077 084 091 008 01 012 014 016

BHF (kN) Die corner radius (mm)

Die clearance (mm) Friction coefficient

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45Th

e max

imum

thin

ning

rate

()

The experimental factors The experimental factors


Figure 4 Relationship between the maximum thinning rate and experimental factors

have a greater risk of cracking and some parts of largerthickening would have a greater risk of wrinkling doubleindexes optimization for process parameters were conductedby integrating these two reasons respectively Single index ofmaximum thinning rate and maximum thickening rate cor-responding to process parameters optimization results aregiven in Table 5 For the two factors the maximum thinningrate and maximum thickening rate are the smaller the betterand the smaller the value is the smaller the risk of crackingand wrinkling on the corresponding parts becomes thedefects of parts also reduce

For the maximum thinning rate die corner radius is thebiggest influencing factor which determines the structure of

die friction coefficient is the secondary influencing factorwhich can be changed by adding the lubricant and changingthe surface roughness BHF can be modified by adjusting theparameters of mechanical presses and die clearance can beadjusted by die repair According to optimization scheme onthe maximum thinning rate the best optimization schemeis A1B3C3D1 with these parameters we take the simulationwith ETADynaform and the results of thickness distribu-tion and forming limit diagram of A1B3C3D1 optimizationscheme are respectively shown in Figures 6 and 7 After theoptimization of process parameters the maximum thinningrate of automotive lower floor board is 2853 the maximumthickening rate is 634 the two rates are controlled in


2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

300 400 500 600 700 0 3 6 9 12BHF (kN) Die corner radius (mm)


063 07 077 084 091 008 01 012 014 016Die clearance (mm) Friction coefficient


Figure 5 Relationship between the maximum thickening rate and experimental factors

the required range and the overall forming quality of partsis better without obvious defects

For themaximum thickening rate the biggest influencingfactor is BHF and is followed by friction coefficient diecorner radius and die clearance have little effect on the max-imum rate of thickening The best optimization scheme formaximum thickening rate is A3B1C1D3 and the simulationresults of thickness distribution and forming limit diagramare respectively shown in Figures 8 and 9 In this case themaximum thinning rate of automotive lower floor board is4010 the maximum thickening rate is 471 Obviouslythe maximum thinning rate exceeds the forming limit andthe automotive lower floor board will be cracked

According to the orthogonal experiment and simulationby Dynaform we chose the friction coefficient with 010BHF with 400 kN die clearance with 084mm and diecorner radius with 9mm to take the actual production ofautomotive lower floor board for experiment The stampingforming part is shown in Figure 10 we can find the lubricanton the surface of automotive lower floor board which isused to reduce the friction coefficient of the parts to avoidthe risk of cracking The wrinkle only occurs in the outerplate where it will be cut off in the next process The finalproduct part is shown in Figure 11 We can find that theautomotive lower floor board is in high quality without anydefects


0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346

UntitledSTEP20 time 0046000Component thickness

xy

z

ETAPOST

lowast

0

Figure 6 Thickness distribution of the forming parts for A1B3C3D1 optimized scheme

CrackRiskof crackSafeWrinkletendencyWrinkleSevere

Insufficientstretch

xy

z

ETAPOST

UntitledStep20 time 0046000FLD middle layerPart blank006

100

080

060

040

020

000minus050 minus030 minus010 010 030 050

wrinkle

Figure 7 Forming limit diagram of the forming parts for A1B3C3D1 optimized scheme

6 Conclusions

In order to study the influence of several process parameterswhich have great influence on the forming quality on thequality of automotive panels this paper adopted automotivelower floor board as the research object selected the BHFdie corner radius die clearance and friction coefficient withmaximum thinning rate and maximum thickening rate asevaluation indexes used orthogonal experiment method forsimulation analysis on the effects of these four parameters

and carried on optimization It can be obtained from theexperiment that the impact of the four process parameterson the maximum thinning rate from strong to weak is dieclearance friction coefficient the BHF and die clearancewhile on the maximum thickening the greatest impact isBHF followed by the friction coefficient and die clearanceand die clearance has little effect The maximum thinningrate and maximum thickening rate could be effectivelycontrolled through orthogonal experiment optimization andthe high quality forming parts can be obtained without



x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled

FLD middle layerPart blank006

100

080

060

040

020


wrinkle

STEP20 time 0052000


Figure 10 Stamping forming part of automotive lower floor board Figure 11 The final product part of automotive lower floor board


obvious defects This paper can also verify the feasibility ofETADynaform simulation software in themoldmanufactur-ing and debugging stage for actual production guidance

Conflict of Interests

The authors declare that they do not have any commercialor associative interest that represents a conflict of interests inconnection with the work submitted

Acknowledgments

This work was supported by the Innovation Foundation forGraduate Students of ShandongUniversity of ScienceampTech-nology (Grant nos YC140105 and YC140205) The authorsexpress sincere thanks to the reviewers for their helpful com-ments and suggestions for improving this paper

References

[1] M Cavazzuti A Baldini E Bertocchi D Costi E Torricelliand P Moruzzi ldquoHigh performance automotive chassis designa topology optimization based approachrdquo Structural and Multi-disciplinary Optimization vol 44 no 1 pp 45ndash56 2011

[2] F Bi S J Hu and B Song ldquoApplication of non-Gaussian closuremethod in automotive chassis non-linear vibration analysisrdquoForschung im Ingenieurwesen vol 75 no 3 pp 153ndash163 2011

[3] N-M Wang and B Budiansky ldquoAnalysis of sheet metal stamp-ing by a finite element methodrdquo Journal of Applied Mechanicsvol 45 no 1 pp 73ndash82 1978

[4] NWang and S Tang ldquoAnalysis of bending effects in sheet form-ing operationrdquo International Journal for Numerical Methods inEngineering vol 25 no 1 pp 253ndash267 1988

[5] M Kawka T Kakita and A Makinouchi ldquoSimulation of multi-step sheet metal forming processes by a static explicit FEMcoderdquo Journal of Materials Processing Technology vol 80-81 pp54ndash59 1998

[6] J Mackerle ldquoFinite element analyses and simulations of sheetmetal forming processesrdquoEngineering Computations vol 21 no8 pp 891ndash940 2004

[7] Y Wen W Zhong and Y Liu ldquoOptimization design of processparameters in sheet metal drawingrdquo Journal of Plasticity Engi-neering vol 20 no 3 pp 31ndash36 2013

[8] J Pan Y Zhong andC Yuan ldquoProcess parameters optimizationfor sheet metal forming during drawing with a multi-objectivegenetic algorithmrdquo Journal of Tsinghua University vol 47 no 8pp 1267ndash1269 2007

[9] E Gao H Li H Kou H Chang J Li and L Zhou ldquoInfluencesof material parameters on deep drawing of thin-walled hemi-spheric surface partrdquo Transactions of Nonferrous Metals Societyof China vol 19 no 2 pp 433ndash437 2009

[10] W Liu and Y Yang ldquoStudy on process optimization and objec-tive functions of sheet metal forming based on FEArdquo MaterialScience and Technology vol 14 no 2 pp 159ndash161 2006 (Chi-nese)

[11] W Chen Sheet Metal Forming CAE Analysis Tutorial ChinaMachine Press Beijing China 2005 (Chinese)

[12] F Barlat and J Lian ldquoPlastic behavior and stretchability of sheetmetals Part I a yield function for orthotropic sheets under

plane stress conditionsrdquo International Journal of Plasticity vol5 no 1 pp 51ndash66 1989

[13] D Ko S Cha S Lee C Lee and B Kim ldquoApplication of afeasible formability diagram for the effective design in stampingprocesses of automotive panelsrdquo Materials and Design vol 31no 3 pp 1262ndash1275 2010

[14] M Firat O H Mete U Kocabicak and M Ozsoy ldquoStampingprocess design using FEA in conjunction with orthogonalregressionrdquo Finite Elements in Analysis and Design vol 46 no11 pp 992ndash1000 2010

[15] K Park and Y Kim ldquoThe effect ofmaterial and process variableson the stamping formability of sheetmaterialsrdquo Journal ofMate-rials Processing Technology vol 51 no 1ndash4 pp 64ndash78 1995

[16] L Chen W Chen J D Li S N Heng and J Wu ldquoOptimaldesign about parameters of cooling pipes in hot stamping dierdquoAdvanced Materials Research vol 988 pp 263ndash267 2014

[17] SWu SheetMetal Forming Technology andMoldDesign North-westernPolytechnicalUniversity Press Xirsquoan China 2002 (Chi-nese)

[18] K Chung K Hyunki and C Lee ldquoForming limit criterion forductile anisotropic sheets as a material property and its defor-mation path insensitivity Part I deformation path insensitiveformula based on theoretical modelsrdquo International Journal ofPlasticity vol 58 no 7 pp 3ndash34 2014

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Algebra

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Decision SciencesAdvances in

Discrete MathematicsJournal of


Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Stochastic AnalysisInternational Journal of


Establish 3D model of partusing ProE

Import the 3D model into Dynaform

Mesh the part and check the model

Blank size estimate and mesh the blank model

Copy and offset the die model andseparate the binder and punch

Define tools position

Set the process parameters

Submit and solve the job

Postprocess and analyze the result

Figure 1 Flowchart of the process simulation

distribution the shape and parameters remain unchangeduse the orthogonal experiment and ETA (engineering tech-nology associates)Dynaform simulation software to analyzeBHF (blank holder force) die corner radius die clearanceand friction coefficient to study impact level of these fourparameters with the results of maximum thinning rate andmaximum thickening rate and optimize these parameters

2 Establishment of Simulation Analysis Model

The simulation process of stamping forming mainly includesthe establishment of 3D model and finite element modelsdefining the forming tools setting the process parametersand analyzing the results The flowchart of the processsimulation is shown in Figure 1

21 Establishment of 3D Model of Part Automotive LowerFloor Board According to the requirements of the analysisdraw three-dimensional model of automotive lower floorboard parts by using ProE firstly Analysis of the partsstructure shows that the parts have large transverse size smalllongitudinal size large drawing depth and complex shapesso final shape should be finished go through drawing rarrtrimming rarr punching rarr shaping rarr flanging rarr lateralpunching rarr trimming and other processes Depending onthe actual production experience the cracking usually occursat the lower portion of both ends of the parts the flat endsand the mid plane may produce insufficient forming On thebasis of the defects the parts may arise necessary process

Figure 2 Drawing die model (die)

Die

Punch

Binder

Blank

Figure 3 The FE model of automotive lower floor board

supplement and binder surface shape design are required toreduce defects in the process of parts stamping Drawing diemodel is shown in Figure 2 the part is defined as die and usedas the forming tool during the simulation and the model issaved as igs format for subsequent finite element modeling

22 Establishment of Finite Element Models Dynaform soft-ware has a total of 16 element types currently the mostcommonly used are Huhges-Liu (HL) shell element andBelytschko-Tsay (BT) shell element and these two elementsare constructed based on the Mindlin plate theory with theadvantages of fast calculation speed and high simulationaccuracy [11] The default element type is Belytschko-Tsayshell element in Dynaform software which is the mostefficient element in explicit algorithm In this paper thedie and sheet metal are meshed by using BT shell elementComprehensively considering simulation accuracy and com-putation time sheetmesh size 12mmand adaptive grade 4 areaccepted And the finite element model of automotive lowerfloor board is shown in Figure 3 In order to ensure the overallforming quality of parts draw bead distribution shape andparameters remain unchangedThe sheet metal use stampingsteel WSS-M-1A365A12 the mechanical properties of thematerials are given in Table 1 and the plate thickness is07mmThe plate is located on binder the constitutivemodelof sheet material applied in this paper is the three parameters






119891 = 119886

10038161003816100381610038161198701

+ 1198702

1003816100381610038161003816

119898

+ 119886

10038161003816100381610038161198701

minus 1198702

1003816100381610038161003816

119898

+ 119888

100381610038161003816100381621198702

1003816100381610038161003816

119898

= 2120590

119898

(1)

where1198701

= (120590119909119909

+ℎ120590119910119910

)21198702

= radic((120590119909119909

minus ℎ120590119910119910

)2)2

+ 1199022

1205902

119909119910


119909


119910




Δ = max(1199050

minus 119905119894

1199050

times 100) (2)

where 1199050



Change (1199050

minus 119905119894

) in formula (2) into (119905119894

minus 1199050



119876 = 119865119902 (3)




Level

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 500 6 11119905 0123 600 9 12119905 014


Number

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 400 6 11119905 0123 400 9 12119905 0144 500 3 11119905 0145 500 6 12119905 0106 500 9 10119905 0127 600 3 12119905 0128 600 6 10119905 0149 600 9 11119905 010


9








1 1198601 1198611 1198621 1198631 3087 6272 1198601 1198612 1198622 1198632 2914 6813 1198601 1198613 1198623 1198633 2863 5874 1198602 1198611 1198622 1198633 3631 5025 1198602 1198612 1198623 1198631 2916 6536 1198602 1198613 1198621 1198632 2907 5537 1198603 1198611 1198623 1198632 3256 5068 1198603 1198612 1198621 1198633 3587 4989 1198603 1198613 1198622 1198631 2944 532



1198701198941

8864 9974 9581 8947 1895 1635 1678 18121198701198942

9454 9417 9489 9077 1708 1805 1715 17401198701198943

9787 8714 9035 10081 1536 1672 1746 15871198961198941

2955 3325 3194 2982 632 545 559 6041198961198942

3151 3139 3163 3026 569 611 572 5801198961198943

3262 2905 3012 3360 512 557 582 529119877 308 420 182 378 120 066 023 075Optimal levels 1198601 1198613 1198623 1198631 1198603 1198611 1198621 1198633




1198941

1198701198942

and 1198701198943


1198961198942

and 1198961198943







15

20

25

30

35

40

45

300 400 500 600 700 0 3 6 9 12

063 07 077 084 091 008 01 012 014 016



The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45Th

e max

imum

thin

ning

rate

()








2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra














119891 = 119886

10038161003816100381610038161198701

+ 1198702

1003816100381610038161003816

119898

+ 119886

10038161003816100381610038161198701

minus 1198702

1003816100381610038161003816

119898

+ 119888

100381610038161003816100381621198702

1003816100381610038161003816

119898

= 2120590

119898

(1)

where1198701

= (120590119909119909

+ℎ120590119910119910

)21198702

= radic((120590119909119909

minus ℎ120590119910119910

)2)2

+ 1199022

1205902

119909119910


119909


119910




Δ = max(1199050

minus 119905119894

1199050

times 100) (2)

where 1199050



Change (1199050

minus 119905119894

) in formula (2) into (119905119894

minus 1199050



119876 = 119865119902 (3)




Level

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 500 6 11119905 0123 600 9 12119905 014


Number

Factors

119860

BHFkN

119861

Die cornerradiusmm

119862

Dieclearancemm

119863

Frictioncoefficient

1 400 3 10119905 0102 400 6 11119905 0123 400 9 12119905 0144 500 3 11119905 0145 500 6 12119905 0106 500 9 10119905 0127 600 3 12119905 0128 600 6 10119905 0149 600 9 11119905 010


9








1 1198601 1198611 1198621 1198631 3087 6272 1198601 1198612 1198622 1198632 2914 6813 1198601 1198613 1198623 1198633 2863 5874 1198602 1198611 1198622 1198633 3631 5025 1198602 1198612 1198623 1198631 2916 6536 1198602 1198613 1198621 1198632 2907 5537 1198603 1198611 1198623 1198632 3256 5068 1198603 1198612 1198621 1198633 3587 4989 1198603 1198613 1198622 1198631 2944 532



1198701198941

8864 9974 9581 8947 1895 1635 1678 18121198701198942

9454 9417 9489 9077 1708 1805 1715 17401198701198943

9787 8714 9035 10081 1536 1672 1746 15871198961198941

2955 3325 3194 2982 632 545 559 6041198961198942

3151 3139 3163 3026 569 611 572 5801198961198943

3262 2905 3012 3360 512 557 582 529119877 308 420 182 378 120 066 023 075Optimal levels 1198601 1198613 1198623 1198631 1198603 1198611 1198621 1198633




1198941

1198701198942

and 1198701198943


1198961198942

and 1198961198943







15

20

25

30

35

40

45

300 400 500 600 700 0 3 6 9 12

063 07 077 084 091 008 01 012 014 016



The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45Th

e max

imum

thin

ning

rate

()








2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra












1 1198601 1198611 1198621 1198631 3087 6272 1198601 1198612 1198622 1198632 2914 6813 1198601 1198613 1198623 1198633 2863 5874 1198602 1198611 1198622 1198633 3631 5025 1198602 1198612 1198623 1198631 2916 6536 1198602 1198613 1198621 1198632 2907 5537 1198603 1198611 1198623 1198632 3256 5068 1198603 1198612 1198621 1198633 3587 4989 1198603 1198613 1198622 1198631 2944 532



1198701198941

8864 9974 9581 8947 1895 1635 1678 18121198701198942

9454 9417 9489 9077 1708 1805 1715 17401198701198943

9787 8714 9035 10081 1536 1672 1746 15871198961198941

2955 3325 3194 2982 632 545 559 6041198961198942

3151 3139 3163 3026 569 611 572 5801198961198943

3262 2905 3012 3360 512 557 582 529119877 308 420 182 378 120 066 023 075Optimal levels 1198601 1198613 1198623 1198631 1198603 1198611 1198621 1198633




1198941

1198701198942

and 1198701198943


1198961198942

and 1198961198943







15

20

25

30

35

40

45

300 400 500 600 700 0 3 6 9 12

063 07 077 084 091 008 01 012 014 016



The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45Th

e max

imum

thin

ning

rate

()








2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra










15

20

25

30

35

40

45

300 400 500 600 700 0 3 6 9 12

063 07 077 084 091 008 01 012 014 016



The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45

The m

axim

um th

inni

ng ra

te (

)

15

20

25

30

35

40

45Th

e max

imum

thin

ning

rate

()








2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra










2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8

The m

axim

um th

icke

ning

rate

()

2

3

4

5

6

7

8Th

e max

imum

thic

keni

ng ra

te (

)










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra










0500254

0517689

0535124

0552559

0569995

0587430

0604865

0622300

0639735

0657170

0674605

0692040

0709476

0726911

0744346


xy

z

ETAPOST

lowast

0



Insufficientstretch

xy

z

ETAPOST


100

080

060

040

020


wrinkle


6 Conclusions





x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra











x y

z

ETAPOST

0419296

0441700

0464105

0486509

0508913

0531318

0553722

0576126

0598531

0620935

0643340

0665744

0688148

0710553

0732957 0

lowast52000

kness



Insufficientstretch

x y

z

ETAPOST

Untitled


100

080

060

040

020


wrinkle

STEP20 time 0052000







Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra













Acknowledgments


References



























Volume 2014




Journal of











Journal of


Function Spaces






Algebra
















Volume 2014




Journal of











Journal of


Function Spaces






Algebra









Documents

Research Article Optimization of Process Parameters of Stamping …downloads.hindawi.com/journals/jam/2014/470320.pdf · 2019-07-31 · Research Article Optimization of Process Parameters