Cylinder Cylinder Contact
Cylinder-cylinder contact force model
Description
Connections
Parameters
The Cylinder Cylinder Contact model connects Cylinder contact elements.
Activation
Contact forces are generated only when the contacts are enabled.
The active parameter selects how the contacts are enabled. It has the following settings:
Always Active, the default, means the contacts are always enabled.
Boolean Signal means the contacts are enabled when the enable contact boolean input is true.
Start/Stop Time means the contacts are enabled at specified start time, Ton, and disabled at a specified stop time, Toff.
The on/off parameter is used with the Start/Stop Time selection and has the following settings:
Start Time means the contacts are enabled at Ton.
Stop Time means the contacts are disabled at Toff.
Start/Stop Time means the contacts are enabled at Ton and disabled at Toff.
Contact Properties
The use record boolean parameter, if enabled, specifies the name of an external record parameter that defines the parameters of the contact.
The mode parameter selects one of three modes: Linear spring and damper, Linear spring and limited damper, and Hunt and Crossley. The first two use the c and d parameters to set the spring and damping constants. The Hunt and Crossley model uses the parameters cn, dn, n, p, and q. See the Multibody Contact Modes help page for the resulting force equations.
The μ parameter is the coefficient of friction between contacting bodies.
The kμ parameter is a smoothness coefficient for sliding friction, it scales μ by tanh⁡kμ⁢vt, where vt is the tangential velocity.
The ε parameter specifies a minimum length used when normalizing vectors.
Name
Modelica ID
enablecontact
Optional boolean input; enable contact
enable_contact
port1
Connection to cylinders
port_1
port2
port_2
Default
Units
active
Always Active
Selects contact activation
on/off
Start Time
Selects start/stop times
onoff
Ton
0
s
On time
Toff
Off time
use record
false
Use contact properties record
useRecord
mode
Linear spring and damper
Contact force formulation
c
104
Nm
Spring constant (c>0)
d
N⁢sm
Damping constant
cn
Nonlinear spring constant (cn>0)
dn
Nonlinear damping constant
n
1.5
Nonlinear elastic force exponent
p
Nonlinear damping force exponent
q
1
μ
Coefficient of friction
mu
kμ
Smoothness coefficient for sliding friction
kTANH
ε
1.×10−6
Minimum length of vectors for normalization
eps
contact properties
Name of contact property record component
conparams
ncylinder1
Number of cylinders at port 1
nCylinder1
use cylinder to cylinder contact at port 1
True means model contacts between the cylinders at port 1
useCylinderCylinderContact1
ncylinder2
Number of cylinders at port 2
nCylinder2
use cylinder to cylinder contact at port 2
useCylinderCylinderContact2
See Also
Forces
Multibody
Multibody Contacts
Download Help Document