Web Properties - MapleSim Help
For the best experience, we recommend viewing online help using Google Chrome or Mozilla Firefox.

Online Help

All Products    Maple    MapleSim


Web Properties

Record of web parameters

 

Description

Usage

Additional Features

Parameters

Description

The Web Properties record specifies the parameters that define the mechanics of the web and its visualization.

Usage

A Web Properties record defines the properties of all the Span components at the same or lower level. By default, all components look for a Web Properties record with the name WP1:

Models can have multiple web types. To accomplish this, where appropriate, the option Use default properties (WP1) must be unchecked, and the specific Web Properties record name entered in the provided record parameter field. Here is an example of a Nip Roller using a non-default Web Properties record with the name WP2.

The default stress/strain relationship is linear (σ=Eε). Clearing the Linear check box replaces this with a nonlinear relationship defined via a lookup table.

Additional Features

Nonlinear Material - Variable Modulus of Elastisity

When the Use constant 'E' option is unselected, new parameters are enabled to define the modulus of elasticity as a function of strain via a lookup table.

Nonlinear Material - Variable Poisson's Ratio

When the Use constant ν option is unselected, new parameters are enabled to define the Poisson's ratio as a function of strain via a lookup table.

Include Mass (Machine Direction)

When the Include Mass (MD) option is selected, all spans in the model activate a second equation for the conservation of momentum. See Span for details.

Start at Equilibrium

When the Start at Equilibrium option is selected, upstream and downstream strain values are set to equal at initialization. In most case this results in the model starting with the web line initialized to the same tension as set at the source.

Prevent Negative Tension

When the Prevent negative tension option is selected, the stress in the span is prevented from becoming negative, however, strain can still become negative to approximately represent web accumulation. For more accurate modeling of such scenarios, use a Sagging Span component.

Visualization

When the Dynamic color option is selected, the user has the choice to have the span (and roller contact arcs) change color based on tension, velocity, width, or strain. When the web speed option is selected, the user has a choice to apply color to roller surfaces as well. This option can highlight large roller slippage.

Parameters

Properties

Name

Default

Units

Description

Modelica ID

W

1

m

Width

W_web

th

1·10−4

m

Thickness

th_web

ρ

1200

kgm3

Density

rho_web

Linear

true

 

When unchecked (false), stress/strain data is used

useLinear

C

1000

Nsm

Linear damping coefficient. Ideally, this value should be set to 1% of the linear modulus of elasticity Enabled when Use constant 'E' is unchecked (false).

C_web

E

4·109

Pa

Modulus of elasticity Enabled when Use constant 'E' is checked (true).

E_web

dr

0.01

 

Damping ratio [0,1] as a fraction of the variable stiffness

dr_web

ν

0.3

 

Poisson's ratio. Enabled when Use constant ν is unchecked (false).

nu_web

Settings

Name

Default

Units

Description

Modelica ID

Include mass (MD)

false

 

When checked (true), the web inertia in the machine direction is included in the span equations.

includeMass

Start at equilibrium

false

 

When checked (true), for each span the strain is initialized to the value given by its upstream component.

start_at_equilibrium

Prevent negative tension

false

 

When checked (true), web stress is prevented from becoming negative.

prevent_negative_tension

Use constant 'E'

true

 

When unchecked (false) stress/strain data is used

useLinear

Use constant ν

true

 

When unchecked (false) Poisson's ratio/strain data is used

useLinear_nu

zoffset

0

m

Z-offset of the web centerline.

z_offset

Stress vs. Strain

Name

Default

Description

Modelica ID

Data source

inline

Data source. There are three options: 1. inline: The data is provided as a two-column matrix in the GUI. 2. file: Browse to the location where the data file is saved. 3. attachment: browse to the location where the data file is saved.  The selected file is attached to the MapleSim file.

datasourcemode

σε

[1]

[2]

table

σε

none selected

file: Browse and select the data file. attachment: Select the attachment that contains the data set.  [2]

data

Skip rows

0

Number of header rows to skip

skiprows

Smoothness

Linear interpolation

Selects interpolation: linear, cubic, spline, or none

smoothness

Stress unit

MPa

Unit of stress used in the data

stressUnit

Strain scale

%

Strain scale in the data

strainUnit

[1] σε=000.140.24.50.34.6

[2] The data should have two columns; the first column is strain, the second column is stress. Each column's unit is defined separately (see Stress unit and Strain scale). Linear extrapoloation based on the last two points of the data is used if strain goes out-of-range.

Poisson's Ratio vs Strain

Name

Default

Description

Modelica ID

Data source

inline

Data source. There are three options: 1. inline: The data is provided as a two-column matrix in the GUI. 2. file: Browse to the location where the data file is saved. 3. attachment: browse to the location where the data file is saved. The selected file is attached to the MapleSim file.

datasourcemode_nu

νε

[1]

[2]

table_nu

νε

none selected

file: Browse and select the data file. attachment: Select the attachment that contain the data set. [2]

data_nu

Skip rows

0

Number of header rows to skip

skiprows_nu

Smoothness

Linear interpolation

Selects interpolation: linear, cubic, spline, or none

smoothness_nu

Strain scale

%

Strain scale in the data (% or m/m)

strainUnit

[1] νε=00.30.10.30.20.20.30.2

[2] The data should have two columns; the first column is strain, the second column is Poisson's ratio values. Linear extrapoloation based on the last two points of the data is used if strain goes out-of-range.

Visualization

Name

Default

Units

Description

Modelica ID

thvis

0.01

m

Thickness for visualization

th_v

Transparent web

false

 

When checked (true), web is transparent

transparent_web

Use tension

false

 

When checked (true), web color is based on its calculated tension

colorMode

Web color

White

 

Web color

web_color

Min value color

Green

 

Minimum value web color

web_color1

Max value color

Red

 

Maximum value web color

web_color2

Roll color

White

 

Roll color.  Only used in wind/unwind drums for the color of the roll

roll_color

τmin

0

N

Minimum Tension: color 1

minTension

τmax

1000

N

Maximum Tension: color 2

maxTension

νmin

0

ms

Minimum Tension: color 1

minVelocity

νmax

1

ms

Maximum Tension: color 2

maxVelocity

Include roller surfaces

true

 

When checked (true) roller surfaces are animated with the same color scheme as for the web speed

includeRollerSurface

ΔWmin

0

m

Minimum width reduction: color 1

minWidthReduction

ΔWmax

0.1

m

Maximum width reduction: color 2

maxWidthReduction

%εmin

0

 

Minimum strain: color 1

minStrainPCT

%εmax

10

 

Maximum strain: color 2

maxStrainPCT

εmin

0

 

Minimum strain: color 1

minStrain

εmax

0.0025

 

Maximum strain: color 2

maxStrain

ndiv

1

 

Number of segments used for web visualization

nDiv

Summary Variables

Name

Value

Description

Modelica ID

Tension unit

N

Unit for summary variable summary_Tension

forceUnitSummary

Length unit

m

Unit for summary variable summary_Length

lengthUnitSummary

Wrap angle unit

degree

Unit for summary variable summary_WrapAngle

angleUnitSummary

Stress unit

MPa

Unit for summary variable summary_WrapAngle

stressUnitSummary

Strain unit

mm

Unit for summary variable summary_WrapAngle

strainUnitSummary

Web velocity unit

ms

Unit for summary variables: summary_SlipVelocity, summary_WebSpeed, and summary_RollerSurfaceSpeed

slipVelUnitSummary

Roller angular velocity unit

RPM

Unit for summary variable summary_RollerAngularVelocity

angVelUnitSummary

See Also

Span

Web Handling