FEM ANALYSISOF
ROLLING PROCESS
DEPARTMENT OF MECHANICAL ENGINEERING, CKPCET
Prepared by:
Varun V. Joshi (100093119001)
Aditya A. Patel (090090119003)
Chetan K. Anghan (090090119006)
Abhishek A. Mukherjee (090090119010)
Guided By :
Prof. Chaitanya K. Desai
Company :
2
When metal passes through rolls, metal starts deforming and stress builds up at
arc of contact. There is residual stress remaining within the rolled product post
rolling.
Finite Element Method (FEM) Analysis is a method of analysis for numerical
solution of field problems. A field problem requires that we determine spatial
distribution of one or more dependent variables.
In our project, we are concerned with cold rolling process only and intend to
obtain the influence of various parameters such as Co-efficient of friction, Plate
feed speed and Roller Velocity on outputs like Von-Mises Stress, PEEQ &
Pressure, whose distributions have already been obtained through different
inputs using FEM software.
INTRODUCTION
FEM ANALYSIS OF ROLLING PROCESS
3
ESSAR Steel, Hazira is a name renowned within the Rolling Industry.
It has the most vast amount of rolling facilities in the country and the various
complexes that are involved in the Rolling process are as follows :
Iron Making Facility
Hot Roll Mill
Cold Roll Mill
In the Cold Roll Mill Complex we observed the following types of Roll Mills
5-Stand Tandem Mill
4-High Single Pass Reversing Mill
COMPANY PROFILE
FEM ANALYSIS OF ROLLING PROCESS
4
LITERATURE REVIEW
FEM ANALYSIS OF ROLLING PROCESS
Sr. No TITLE YOP
1SIMULATION OF PLANE-STRAIN ROLLING BY THE RIGID-PLASTIC FINITE
ELEMENT METHOD1981
2SIMULATION OF THE COLD ROLLING OF STRIP USING AN ELASTIC-
PLASTIC FINITE ELEMENT TECHNIQUE1985
3A RIGID-PLASTIC FINITE ELEMENT ANALYSIS OF TEMPER ROLLING
PROCESS2002
4ELASTO-PLASTIC FINITE ELEMENT SIMULATION OF A SYMMETRICAL
PLATE ROLLING USING AN ALE APPROACH2006
5INVESTIGATION OF INFLUENCE PARAMETERS ON THE HOT ROLLING
PROCESS USING FINITE ELEMENT METHOD2010
6 ROLLING MILL ROLL DESIGN 2003
7NON LINEAR FINITE ELEMENT METHOD SIMULATION AND MODELING OF
COLD AND HOT ROLLING PROCESSES.2007
5
CLASSICAL APPROACH TO ROLLING
FEM ANALYSIS OF ROLLING PROCESS
The formulation of the problem based on classic approach is done by SLAB
METHOD.
6
FINITE ELEMENT ANALYSIS
FEM ANALYSIS OF ROLLING PROCESS
Before we proceed to the formulation of problems and their simulation there are
some basic concepts that one should be familiar with:
QUASI-STATIC SIMULATIONS USING EXPLICIT DYNAMICS
MASS SCALING
ALE method
Element: CPE4R(4 node bilinear plain strain , quadrilateral , reduced
integration, hourglass control)
7
FEA ROLLING ASSUMPTIONS
FEM ANALYSIS OF ROLLING PROCESS
These are the assumptions that we have taken in our simulations:
The arc of contact between the rolls and the metal is a part of a circle.
The coefficient of friction, µ, is constant in simulation, but in actual
scenario, µ varies along the arc of contact.
The metal is considered to deform plastically during rolling.
The volume of metal is constant before and after rolling. In actual scenario,
the volume might decrease a little bit due to close-up of pores.
The velocity of the rolls is assumed to be constant.
The metal only extends in the rolling direction and no extension in the
width of the material.
The cross sectional area normal to the rolling direction is not distorted.
8
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
When we went to the industry, they asked us to formulate a basic simulation
model. This was the simulation model we had formed.
2D Deformable plate
Analytical Rigid Wire
9
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
10
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
Reference
Point
Point of Instance
11
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
Roller Fixed
Upward Movement
restricted
Plate Feed
Velocity
12
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
This is the ALE meshed part. Element used is CPE4R. Total
no. of elements is 460.
13
IBSM - SOLUTION
FEM ANALYSIS OF ROLLING PROCESS
14
SHEET SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
Based on our Initial Basic Simulation Model, the industry provided us with the
following data.
Length : 1500 mm
Initial Sheet Thickness : 5 mm
Final Sheet Thickness : 4 mm
Sheet Feed Velocity : 1.5 m/s
Roller Diameter : 380 mm
Roller Velocity: 200 MPM (20 Rad/s)
Initial Material Hardness : 50-60 HRB
Post-Rolling Material Hardness : 90 HRB
Post-Annealing Material Hardness : 60 HRB
c
15
SHEET SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
The further steps are to be carried out in a similar manner to the way the plate
problem was formulated.
16
SHEET SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
17
SHEET – VMS DISTRIBUTION
FEM ANALYSIS OF ROLLING PROCESS
18
SHEET – PEEQ DISTRIBUTION
FEM ANALYSIS OF ROLLING PROCESS
19
SHEET - PRESSURE DISTRIBUTION
FEM ANALYSIS OF ROLLING PROCESS
-50
0
50
100
150
200
250
300
350
400
450
0 2.3 4.53 6.7 8.8 11 13.13 15.27 17.42 19.55 21.73 23.89 26.07 28.28 30.48 32.7
Str
ess
True distance along path
Pressure Distribution along Arc of Contact
Pressure
20
VARIATION IN RESIDUAL STRESSES
As seen in earlier slides, we obtained the Von-Mises Stress distribution.
Once the Roll force is removed, the stress remaining in the Sheet may be
considered as Residual Stress.
Now we proceed to see the variation in the residual stresses based on the
following parameters:
•Co-efficient of friction f
•Plate Feed Velocity Vp
•Roller Velocity Vr
FEM ANALYSIS OF ROLLING PROCESS
21
CO-EFFICIENT OF FRICTION f
150
155
160
165
170
175
180
185
190
195
200
0.2 0.25 0.3 0.35 0.4 0.45
Vo
n M
ises
/ R
esid
ua
l S
tres
ses
Co-Efficient of Friction f
Residual Stress v/s Co-eff of Friction f
Residual Stresses
Residual stresses initially increase with increase in Co-efficient of
Friction f upto value = 0.35 and then decreases
FEM ANALYSIS OF ROLLING PROCESS
22
PLATE FEED VELOCITY VP
Residual stresses decreases with increase in plate feed velocity Vp upto
value = 1.5 and then has a sudden increase.
0
50
100
150
200
0.25 0.5 0.75 1.25 1.5 1.75
Vo
n-M
ises / R
esid
ual
Str
esses
Plate Feed Velocity Vp
Residual Stresses v/s Vp
Residual Stresses
FEM ANALYSIS OF ROLLING PROCESS
23
ROLLER VELOCITY VR
Residual stresses remains more or less constant with increase in plate
feed velocity Vp, but experiences a sudden drop at value = 9 and then
again follows the earlier established trend.
130
135
140
145
150
155
7 8 9 9.5 10 10.5
Vo
n-M
ises / R
esid
ual
Str
esses
Velocity of Roller Vr
Residual Stresses v/s VR
Residual Stresses
FEM ANALYSIS OF ROLLING PROCESS
24
OPTIMUM PARAMETERS
Based on all the above graphs, we may conclude that there is a
most optimum combination of parameters which would result in
an overall reduction in the residual stresses.
Co-efficient of Friction f = 0.45
Velocity of Plate Feed VP = 1.5 m/s
Velocity of Roller VR = 9 rad/s
FEM ANALYSIS OF ROLLING PROCESS
25
SCOPE OF FUTURE WORK
FEM ANALYSIS OF ROLLING PROCESS
When we formulated the shell problem, in the job analysis stage we found
excessive deformation in the roller outer surface and the plate. This was
perhaps due to incorrect load and boundary conditions that we had applied. In
spite of our best efforts, we were unable to remove and eliminate the error and
hence there remains a scope for future work in that direction.
THANK YOU
Top Related