Multi-Web Roller Out
Exit condition for the merged web
Description
Usage
Equations
Connections
Parameters
Summary Variables
The Multi-Web Roller Out component captures the merging of multiple webs and the exit configuration for the merged web.
A Multi-Web Roller Out component is only used with 2 or more Multi-Web Roller In components.
Example:
The above arrangement can be replaced by the following:
Consider a portion of the web between two boundaries a and b (i.e. a control volume). Assume the web velocity goes through a discontinuous change at the left (entry) boundary which is at the roller location.
Ta1⋯Tan
Upstream tensions
Tb
Downstream tension
va
Upstream speed
vb
Downstream speed
τ1,τ2
Motor torque applied to roller 1 and 2
R1,R2
Roller effective radius
ω1,ω2
Roller angular velocity
J1,J2
Moment of inertia or roller 1 and 2
W
Web width
β
Wrap angle
The incoming velocities match the roller velocity under the no-slip conditions
v__a=v__b,v__a=R__1⁢ω__1,v__b=R__2⁢ω__2
The conservation of mass for the control volume can be expressed as
∂∂t∫a__ax__bρ⁡x,t⁢A⁡x,tⅆx=v__a⁡t⁢∑i=1n⁡ρ__a__i⁡t⁢A__a__i⁡t−ρ__b⁡t⁢A__b⁡t⁢v__b⁡t
Based on the above assumption we can write
∂∂tρ⁢A⁢L=v__a⁢∑i=1n⁡ρ__a__i⁡t⁢A__a__i⁡t−ρ__b⁡t⁢A__b⁡t⁢v__b⁡t
where L=xb−xa and we dropped t to simplify the notation.
The mass of an infinitesimal length of the web is
dm=ρ__u⁢A__u⁢dx__u
where subscript u is for the undeformed state.
The element strain in the Machine Direction (MD) can be written as:
dx=dx__u⁢1+ε
Putting (4) and (5) together, we get:
ρ⁢A=ρ__u⁢A__u1+ε
Substituting (6) into (3) and simplifying yields:
∂∂tL1+ϵ__b=v__a⁢∑i=1n⁡ρ__ai⁢A__ai1+ϵ__aiρ__b⁢A__b−v__b1+ϵ__b
What remains is the material's constitutive equation. Assuming linear visco-elastic material (Kelvin–Voigt model), we have, for i=1..n:
T__a__i=E__a__i⁢A__a__i⁢ϵ__a__i+d__r__a__i⁢ⅆϵa__iⅆt
T__b=E__b⁢A__b⁢ϵ__b+d__r__b⁢ⅆϵbⅆt
The control volume is selected such that it covers the entire web span from one roller to the next. Under no-slip conditions, the portions of the web in contact with the rollers are neglected.
Finally the tension/torque relationship can be written as:
J1⁢ⅆⅆtω1+J2⁢ⅆⅆtω2+d⁢ω1+ω2=τ1−R1⁢∑i=1n⁡Ta__i−TbSide=1τ2−R2⁢∑i=1n⁡Ta__i−TbSide=2
Name
Modelica ID
flangec1
Roller rotation flange (enabled when Side=1
flange_c1
flangec2
Roller rotation flange (enabled when Side=2
flange_c2
frameb
Right web 3-D connection point
frame_b
framec
Roller holder base frame
frame_c
webb
Right (exit) web transfer information port (green)
web_b
webs
Multi-Web transfer information port (gray)
v
Real output ; velocity
T
Real output ; tension in web
Webs
Default
n
2
Number of merging webs
Incoming Web Properties
Names of Web Properties records defining the incoming webs
wp_i
Combined Web Properties
Names of Web Properties records defining the outgoing web
wp_o
Settings
Side
1
Select actuated roller: 1 or 2
Use alternative configuration
false
Choose between two possible solutions for the web/roll configuration for the merged web
useAltConfig
Flip direction
Use this option when building web lines that go from right to left
flipDirection
Roller
Units
D1
0.2
m
Diameter of roller 1
Di1
0
Inner diameter of roller 1
D2
Diameter of roller 2
Di2
Inner diameter of roller 2
L
1.2
Roller length
Use cylindrical geometry
true
When checked (true), roller inertia is calculated assuming a uniform cylindrical geometry
useCylindricalGeometry
ρ
2.7·103
kgm3
Roller density; enabled when using cylindrical geometry
rho_roll
m1
kg
Roller 1 mass; enabled when not using cylindrical geometry
m2
Roller 2 mass; enabled when not using cylindrical geometry
J1
0.005
kg⁢m2
Roller 1 rotational inertia; enabled when not using cylindrical geometry
J2
Roller 2 rotational inertia; enabled when not using cylindrical geometry
d
N⁢m⁢srad
Bearing viscous damping constant (both rollers)
Frame
Reference frame
Middle of the gap
Select option for the location of the framec (holder). There are three options available: Middle of the gap, Center of roller 1, and Center of roller 2
Ref_pos
mf
Frame mass
m_frame
Jf
0.01
Frame inertia
J_frame
Y
Offset from the reference point in the Y direction
Visualization
Show roller 1
When checked (true), a visualization of roller 1 is created
showVisualization_roller
Show roller 2
When checked (true), a visualization of roller 2 is created
showVisualization_second
Transparent roller
When checked (true) the roller visualization is transparent
transparent_roller
Roller color
Blue
color_roller
Band color
Yellow
color_band
Band angle
20
deg
band_angle
Show frame
When checked (true), a visualization of the frame is created
showVisualization_frame
Transparent frame
When checked (true), the roller visualization is transparent
transparent_frame
Frame color
Orange
color_frame
Web Sensor
Use sensor
When checked (true), two signal outputs are enabled for the tension in the span and the material transfer speed
useSensor
Velocity output unit
ms
Selects units of the velocity output; enabled when Use Sensor=true
toUnitV
Force output unit
N
Selects units of the force output; enabled when Use Sensor=true
toUnitF
Advanced Settings
Use effective radius
When checked (true), the roller radius is padded with half the web thickness
useEffectiveRadius
summary_WrapAngle
rad
summary_Length
Length of the web in contact with the roller
See Also
Laminating
Web Handling Library
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