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INTRODUCTION

Sheet metal forming is one deformation process whichtransforms a metal blank into a component

Wrinkling and tearing are the most prevalent materialinstabilities that occur in sheet metals formed by stampingand deep drawing processes

Finite Element Analysis (FEA) is a numerical simulation

that allows us to evaluate product manufacturability andpredict the defects at early stages of the design process

OBJECTIVES

To identify part defect of an automotive stamped part

To simulate the selected part using DYNAFORM softwareto analyze its formability

To optimize the part process to reduce cost and save time

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PROBLEM STATEMENT

Many company still using trial and error method to obtainthe most acceptable process to produce their partsResulting time consuming, high cost and error to determinethe accuracy of actual designStamped part have a crack and tearing defectsRecommended step for the stamped part

SCOPE OF PROJECT

Automotive stamped part collected from Autokeen Sdn.Bhd.

Actual design will go through the numerical simulation byusing DYNAFORM software to analyze the formability of the partThe data will be collected and recommendation is made tooptimize the part process

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SIGNIFICANCE OF PROJECT

Impart the knowledge and understanding on the concepts of stamping die

eta/DYNAFORM software can be used as simulation toolfor the numerical analysis and can reduced try and errormethod

The drawing steps is reduced to get lower cost and higherproduction efficiency

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SpecificationPart name BRACKET ASSEMBLY SPRING UPPER

Drawing no. MR491947

Process(i) Semi progressive, 250 tonne

(ii) Flange, pierce, 110 tonne

Material SPCC, thickness = 2.3mm

Dies Material Surface Treatment

Upper punch SKD11 Full hardened

Lower punch SKD11 Full hardened

Machine name Komatsu 250 tonne

PART IDENTIFICATION

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Convert the CATIA drawing to .iges file

in the CATIA software

Import the .iges file into theeta/DYNAFORM software

Generate inner and outer surface of thepart to set the punch and die.

Generate blank and blank holder (orbinder) in 1 st Draw

Generate upper pad and lower pad (orbinder) in 2 nd, 3 rd and 4 th draw

Run the LS-Dyna Analysis in theAUTOSETUP menu

Open the analysis result by using theETA/Postprocessor

STEP TO DO THE ANALYSIS BY USING LS-DYNA

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Actual Simulation

2nd draw output

Draw stage 1 2 3

% from failure zone 64.15 - -

Minimum Thickness (mm) 2.053 0.596 0.089

Maximum Major Strain 0.231 1.279 3.271

SUMMARY RESULTS FOR 3 STAGES OF DRAW

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Actual Simulation

4 th draw output

Draw stage 1 2 3 4

% From Failure Zone 40.82 40.00 39.13 9.43

Minimum Thickness

(mm)1.773 1.823 1.564 1.384

Maximum Major Strain 0.305 0.450 0.620 0.807

SUMMARY RESULTS FOR 4 STAGES OF DRAW

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DISCUSSION OF PART SIMULATION

The FLD shows the critical combinations of major strainand minor strain in the sheet surface

Safety curve verify whether a stamping will be crack free

FLC limit of the drawn part to be crack

FLC

SafetyCurve

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OPTIMIZATION PROCESS FLOW

Identify required steps

Estimate blank diameter

Determine the number of draws

Optimal ratio of reduction

Design in CATIA software

Simulate using DYNAFORM software

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DISCUSSION OF PART PROCESS OPTIMIZATION

Through the analysis comparison between optimizationprocess and four stages draw process, the optimizationprocess is more preferable process to be implemented

Optimization Process Four Stages Draw Process

% From Failure Zone 48.44 9.43

Thickness Distribution 1.837 1.384

Major Strain 0.576 0.807

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Optimization Process 4 stages draw process

Forming LimitDiagram

ThicknessDistribution

Major Strain

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CONCLUSION

The analysis proved that the optimization process is morepreferable method as compare to the previous four stagesprocess

The more percentage from the failure zone means the parthas a better quality

25 percent of the die material, scrap and time can be savedby eliminating one stage of the draw process

OptimizationProcess

Four Stages DrawProcess

Total cost(per unit)

RM 3.66 RM 3.89

Timeconsumed(per unit)

24 sec 28 sec