using fe to simulate the effect of tolerance on part deformation
DESCRIPTION
Using FE to simulate the effect of tolerance on part deformation. By I A Manarvi & N P Juster University of Strathclyde Department of Design Manufacture and Engineering Management. Outline. Introduction Methodology Experimental phase Procedure - PowerPoint PPT PresentationTRANSCRIPT
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Using FE to simulate the effect Using FE to simulate the effect of tolerance on part of tolerance on part
deformation deformation By
I A Manarvi & N P Juster
University of Strathclyde
Department of Design Manufacture and Engineering Management
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Outline Outline • Introduction• Methodology • Experimental phase• Procedure • Tolerance Vs. deformation experimental results• FE simulations • Tolerance Vs. deformation FE results• FE deformation pattern at tolerance values • Comparison of Experimental and FE results• Conclusions
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IntroductionTolerance Allocation in Product Design: a) Vital activity for mass production and interchange-
ability of parts
b) Required during design, Manufacturing, Assembly, Quality and performance evaluation phases.
Major influences on function, cost, customer requirements and aesthetics.
Scope :
Investigating use of FE simulations as a tool to verify influence of tolerance on part deformation at initial design stages
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MethodologyExperimental phase: a) Selection of specific type of tolerance , a simplified
geometry and commonly used materialb) Design and manufacturing of a test rig for
experiments simulating tolerance conditions. Execution of experiments and collection of data
FE simulation phase:a) FE modelling and simulation with ABAQUS
software with similar boundary conditions as experiments.
b) Collection of FE results at same Axis location as of experimental data
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Known Parameters: a) Selection of tolerance: Location of two hole centresb) Simplified geometry: Rectangular strip 200 x 40 x 1 mmc) Material : ABS plastics ( Astyrn BR 712 A)
Test rig designed and manufactured:
Base Platform
Parallel Precision slides
Side supports
Sliding platform
Rotary Knob
Dial Indicator 1
Dial Indicator 2
Dial Indicator 3
Experimental Phase
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Procedure
Specimen Rotary knob
Pin B (0.2, 0.4, 0.6, 0.8, 1.0, 1.2mm)
Pin A (Fixed)
Z
Y
X
Y
Z
Dial Indicator 1 for tolerance measurement
Dial Indicator 2,3 for side deflection measurement
Out of plane deformation Z axis
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Tolerance vs. Deformation Experimental Results
-10
-8
-6
-4
-2
0
1 3 5 7 9 11 13 15 17
Length x 10mm
Def
orm
atio
n (
mm
)
0.2mm 0.4mm 0.6mm
0.8mm 1.0mm 1.2mm
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FE simulations
Material properties: ABS plastics ( Astyrn BR 712 A)
• Material type = Elastic
• Young’s Modulus = 106 e 3 MPa
• Poison’s ratio = 0.39
Analysis steps : Initial & Step 1 with assumptions as:
• Non linear geometries ON
• Buckling criteria = Static Riks
Model creation: Rectangular strip 200 x 40 x 1 mm
40200
1
180
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FE SimulationsBoundary conditions:
YX
ZPin B Pin A
Ux = 0.0Uy = 0.0Uz = 0.0Rx = 0.0Ry = 0.0Rz = 0.0
Ux =FreeUy =FreeUz =FreeRx =FreeRy =FreeRz =Free
Pin B would move in steps to 0.2, 0.4, 0.6, 0.8, 1.0, 1.2 mm in X-axis
Meshing conditions:
Mesh seeds = 2mmElements = Hexagon
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Tolerance vs. Deformation FE Results
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
1 3 5 7 9 11 13 15 17 19
Length x 10 (mm)
Def
orm
atio
n (
mm
)
0.2mm 0.4mm 0.6mm
0.8mm 1.0mm 1.2mm
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FE Deformation Pattern of Model at Different Tolerance values
0.2 mm
0.4 mm
0.6 mm
0.8 mm
1.0 mm
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Comparison of Experimental and FE Deformation at 0.2, 0.4 & 0.6mm
0.0
1.0
2.0
3.0
4.0
1 2 3 4 5 6
Length X 10 (mm)
Defo
rmat
ion
(mm
)
FE 0.2mm Exp 0.2mm
0.0
1.0
2.0
3.0
4.0
5.0
6.0
1 2 3 4 5 6Length x 10 (mm)
Defo
rmati
on (m
m)
FE 0.4mm Exp 0.4mm
0.0
2.0
4.0
6.0
8.0
1 2 3 4 5 6
Length x 10 (mm)
Defo
rmati
on (m
m)
FE 0.6mm Exp 0.6mm
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0.0
2.0
4.0
6.0
8.0
1 2 3 4 5 6Length x 10 (mm)
Def
orm
ation
(mm
)
FE 0.8mm Exp 0.8mm
0.0
2.0
4.0
6.0
8.0
10.0
1 2 3 4 5 6Length x 10 (mm)
Def
orm
ation
(mm
)
FE 1.0mm Exp 1.0mm
0.0
2.0
4.0
6.0
8.0
10.0
1 2 3 4 5 6
Length x 10 (mm)
Def
orm
atio
n (m
m)
FE 1.2mm Exp 1.2mm
Comparison of Experimental and FE Deformation at 0.8, 1.0 & 1.2mm
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FE Analysis of complex geometry
2.07 1.97
1.87
1.66
0.00
0.42
1.04
1.35
1.56
1.76
0.62
0.73
0.83
0.93
IDEAS VISUALISERFEM 1 B.C. 1, DISPLACEMENT_1, RESTRAINT SET 1 DISPLACEMENT Magnitude Un averaged Top Shell Min: 0.00 mm Max: 2.07 mm
X
Y
Z
Y= 1.0mm Rest all DOF set free
All DOF constrained
All DOF free
All DOF free
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FE Analysis of complex geometry
Hole C Y= 1.0mmRest all DOF set free
All DOF constrained in Hole A
All DOF constrained in Hole B
IDEAS FEM 1 B.C. 1, DISPLACEMENT_1RESTRAINT SET 1 ELEMENT SIZE = 0.2mmType: Thin shell 2.5mm thicknessNo. of Elements = Over 400,000
Hole D No constrain applied
XZ
Y
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FE Analysis of complex geometry
0.00
2.72
2.44
2.172.04
1.491.36
1.22
0.68
0.540.410.27
0.14
0.820.951.09
1.631.771.90
2.31
2.58
mmUn deformed modelDeformed model
No deformation Zone
Maximum deformation Zone due to 1.0mm tolerance
Deformed modelUn deformed model
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FE Analysis of complex geometryIDEAS FEM 1 B.C. 1, DISPLACEMENT_1RESTRAINT SET 1 ELEMENT SIZE = 2.5mmType: Thin shell 2.5mm thickness No. of Elements = Over 400,000
Y= 1.0mm
Rest all DOF set free
All DOF constrained
All DOF constrained
No constrain applied
Y
Z
Y
SIDE VIEWFRONT VIEW
X
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FE of Automotive Glove boxIDEAS VISUALISER FEM 1 FRONT VIEW B.C. 1, DISPLACEMENT_1, RESTRAINT SET 1 DISPLACEMENT Magnitude un averaged Top Shell Min: 0.00 mm Max: 3.86 mm
0.00
3.86
3.48
2.70
1.931.74
1.55
0.77
0.58
0.39
0.19
0.14
0.97
1.16
1.35
2.12
2.32
3.28
mm
2.51
2.90
3.67
Max. deformation
No deformation
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Conclusions Peak deformation at center of specimen reducing
towards edges. FE and experimental results showed tolerance
leading to deformation subsequently influencing part assembly
Existence of a linear relationship between tolerance and deformation of parts confirmed by FE and experiments
Similarity of experimental and FE results signified the possibility of using FE as a tool for tolerance allocation.
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Thank You for attentionThank You for attention
Questions ?