AUT UNIVERSITY
TE WANANGA ARONUI O TAMAKI MAKAU RAU
Simulation of Roll Forming
Florian Kern
Thomas Neitzert
Outline
•
Introduction
•
Roll forming
•
New developments
•
Simulation of U-channel
•
Summary and future work
Roll Forming
• Bending process
• Angle introduced
continuously along straight line
• Set of contoured rolls
• Strip motion applied by rotation of rolls (friction)
• Alternatively, pulling of strip
• Unlimited length
Source: Schuler
Roll Forming - Boundaries
• Generally, materials that can be bent can also be roll
formed
• Steel:
–
–
–
–
Thickness 0.1mm to 20mm
Width 3mm to 2m
Velocity 20m/min to 80m/min, some up to 160m/min
More demanding for higher yield strengths
• Product is prismatic
Typical Defects in Roll Forming
• Camber
– Curving in horizontal plane
• Bow
– Curving in vertical plane
• Twist
– Rotation around
longitudinal axis
Source: Halmos
y
Roll Forming – Latest Developments
x
z
• Flexible roll forming
Source: PtU
• Rolls with addition DOF
– Rotation
– Lateral translation
• NC
y
Source: PtU
• Variable cross sections
Source: PtU
x
Source: PtU
Roll Forming – Latest Developments
• MONRO
• Variable cross-section, different
scale
• Stands separated, each side
movable
• Applied as cladding of large
buildings
Source: The Fabricator
Source: BEMO Systems
Forming specialities
• Linear flow splitting
Source: PtU
Source: PtU
Source: PtU
• Double-sided flanges without
joints
• Cold forming
• Excellent surface quality
• Considerable increase in
hardness
Integration of processes
Laser assisted bending
• Appreciable extension of forming limits of
high strength steel (up to 200%)
• Hardly any permanent softening of steel
Source: LFT
Aides for Manufacturing
• Simulation of forming process
– Several software packages
specialised on roll forming
•
•
•
•
•
PROFIL (Ubeco)
COPRA (dataM)
Shape-RF (SHAPE Co)
Simply Roll Design (Delta Engineering)
VTTube (VTT)
Source: SHAPE
Source: dataM
Simulation of U-channel
•
•
•
•
•
Abaqus explicit
6 stands
Stand spacing 300mm
4-node shell elements (S4R)
Symmetric
Model parameters
Material
Isotropic, linear
hardening
Young’s modulus
210GPa
Yield strength
300MPa
Strip Thickness
1mm
Strip Velocity
1mm/ms
Coefficient of Friction
0
Roll diameter
200mm
Roll material
Analytically rigid
Tool
• Constant Radius
• 15° angle increment
56
49
1
R3
150
Simple U-Channel
Results: Strains at channel edge
Shear
Strains at edge of flange (top)
Longitudinal
0.002
Transverse
0.0015
0.001
Strain
0.0005
0
-0.0005
-0.001
-0.0015
-0.002
-0.0025
0
1
2
3
4
5
6
Stands
Shear
Strains at edge of flange (bottom)
Longitudinal
0.002
Transverse
0.0015
0.001
Strain
0.0005
0
-0.0005
-0.001
-0.0015
-0.002
-0.0025
0
1
2
3
Stands
4
5
6
Results: Stresses at channel edge
Shear
Stresses at edge of flange (top)
Longitudinal
0.3
Transverse
0.2
Stress (Gpa)
0.1
0
-0.1
-0.2
-0.3
0
1
2
3
4
5
6
Stands
Shear
Stresses at edge of flange (bottom)
Longitudinal
0.3
Transverse
0.2
Stress (Gpa)
0.1
0
-0.1
-0.2
-0.3
0
1
2
3
Stands
4
5
6
Roll Former at AUT
• 7 Stands (5 currently in use)
• Rolls supported at both ends
(Standard design)
• All lower and first upper roll
driven ( line of transfer gearboxes)
• Max. strip width: 350mm
• Old production tool installed
• Cut-off die
• Decoiler
Simulation of existing tool
Summary and future work
• New developments
• Created simulation of
– U-channel and
– Production tool
• Develop versatile research tool
• Verify simulation
• Progress to more complex geometry
• Develop design aide for roll forming
Thank you