stamping simulation model for titanium sheet...stamping simulation model for titanium sheet y....
Post on 27-Jun-2020
2 Views
Preview:
TRANSCRIPT
Stamping Simulation Model Stamping Simulation Model for Titanium Sheetfor Titanium Sheet
Y. Y. ItamiItami, K. , K. TokunoTokuno and T. and T. OdaOdaNipponNippon Steel CorporationSteel Corporation
Titanium 2006 San Diego, CAOctober 3, 2006
Table of contentsTable of contents
1)IntroductionExamples of stamping application
2) Considerable Condition on titanium stamping simulation
3)Development of stampingsimulation model
4)Conclusion
Stamping application for I.T. body partsStamping application for I.T. body parts•• Stamping requirement at customersStamping requirement at customers
1) Dimensional precision forming2) Difficult forming
Application areas are widening & increasing !However, there are some difficulties in
titanium stamping
Recent example of titanium stamping products
Sony Network walkman NW-MS70D 2003/02
SONY Linear PCM recorder PCM-D1 2005/11
Recent example of titanium stamping products
Recent example of titanium stamping parts
Sony net walkman
Stage #1 #2 #3 #4
Difficult forming: Increasing stamping stages
Examples of precision forming Sharp corner
They used Nippon Steel material
Dents portion
Recent example of titanium stamping parts
1.Mechanical property
2.Lubrication
3.Die design (Process design)
Considerable condition Considerable condition on titanium stamping on titanium stamping simulationsimulation
1. Mechanical property
Plasticity anisotropy
0
100
200
300
400
500
600
700
0 0.1 0.2 0.3 0.4 0.5
True strain /
True
st
ress
/M
Pa
Longitudinal 0 deg.45 deg.90 deg.
Anisotropic work-hardening of pure titanium
Experiment equipment of yield-surface measurement
Laser CCD for
Curvature, Radius measurement
CCD Camera for
Longitudinal Strain measurement
Axial Force
Internal Pressure
Stress ratio control system
Yield surface of titanium (r0=1.7r45=4.3r90=4.8)
-200
0
200
400
600
800
1000
-200 0 200 400 600 800 1000
M eridional stress σφ /M Pa
Circumferential stress σ
Θ /MPa
0.01
0.02
0.05
0.1
0.15
0.01
0.02
0.05
0.1
0.15
εeq
Steel
σθ σθ
σφ
σφ
• Lubricating method( reducing friction )
• Life of die(preventing crack initiation ,
seizure, galling)
2. Lubrication Conditions2. Lubrication Conditions
Effect of lubrication on forming height
No lubrication Normal lubrication
Good lubrication
Height=9mm Height=11mm
Height=14mmErichsen cup test :Sheet thickness= 0.5mm
3.Die design (Process design)3.Die design (Process design)
““Try and ErrorTry and Error”” increases costsincreases costs
Conner radius, Clearance , Blank Hold Force(BHF), etc
Shock-line
a) Clearance: small
Material
Punch
b)Clearance: large
No shock-line
Die
Effect of clearance on shock-line
• Deformation behavior of titanium1)Large plastic anisotropy2)Anisotropic work-hardening
(Steel follows isotropic hardening rule )
• Frictional resistanceEffect of friction coefficient
• Full 3D FEM simulationConsideration of thickness
direction stress
Development of stamping Development of stamping simulation model for titanium sheetsimulation model for titanium sheet
Measuring yield-surface
Constitutive equation
3D elastic-plasticFEM simulation
Development of stamping Development of stamping simulation model for titanium sheetsimulation model for titanium sheetConventional model• Plane stress model σz=0 and τyz =0 and τyz=0
anisotropic work hardening not considered
Development model• Full 3-dimensional model a1(σy-σz)2+ a2(σz-σx)2 + a3(σx-σy)2
+a4τyz2+ a5τyz
2+ a6τxy2=σ2
anisotropic work hardening consideredThickness direction stress considered for ironing
σzσx
σy
σx
σy
Meshing of 3D FEM simulation model
5 divisions in thickness direction
t=0.5mm
CanningShock line
Experiment 3D-FEM simulation
Square-shell deep drawing
An example of stamping titanium
Deformation of titanium sheet (Animation )
Thickness direction strain distribution (Animation)
Forming- load simulation during stamping
0
10
20
30
40
0 10 20 30Forming height /mm
Stam
ping
load
/ k
N
MeasureCalculation
Flange-profile simulation of titanium sheetH=0mm 20mm10mm 30mm
Calculation Experiment3-dimensionalshape measurement
9045
0deg
Thickness distribution of square deep-drawing(H=30mm)
Calculation Experiment
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0 50 100 150Distance from center /mm
Thic
knes
s /m
m45deg.90deg.0deg.
B.H.F=10kNµ=0.03
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0 50 100 150Distance from center /mm
Thic
knes
s /m
m
45deg.90deg.0deg.
B.H.F=10kN
The application and The application and solution of titanium stampingsolution of titanium stamping
Part design
Process design
Forming validation
Simulation modelSimulation modelPredict and solve difficulties:• Material mechanical properties• Lubrication • Die design
Recommend::• Die-design• Stamping condition • Materials
Coming soonComing soon
• Digital camera body parts
Photokina world imaging in Köln 26.09.2006
Debut
ConclusionConclusionIn the FEM simulation, both anisotropy of
plasticity and anisotropic work hardening model were adopted for high precision calculation of titanium stamping.
• Thickness strain distribution and deformation of blank (material plastic flow from flange) caused by stamping were consistently calculated using the FEM model.
• The results were in good agreement with behaviors of square-shell deep drawing of pure titanium sheets observed in experiments.
top related