-
Specifying frictional behavior for
mechanical contact property options
You
can specify a friction model that defines the
force resisting the
relative tangential
motion of the surfaces in a mechanical contact
analysis. For more information, see
?
Frictional
behavior,
?
Section
35.1.5 of the Abaqus
Analysis User's Manual
.
To
specify frictional behavior:
1.
From the main menu bar,
select
Interaction
Property
Create
.
2.
In the
Create Interaction
Property
dialog box that appears, do
the
following:
?
Name the interaction property. For more
information about
naming objects, see
?
Using basic dialog box
components,
?
Section 3.2.1
.
?
Select the
Contact
type of interaction
property.
3.
Click
Continue
to close the
Create Interaction Property
dialog box.
4.
From the menu
bar in the contact property editor, select
Mechanical
Tangential
Behavior
.
5.
In
the editor that appears, click the arrow to the
right of the
Friction
formulation
field, and
select how you want to define friction between
the contact surfaces:
?
Select
Frictionless
if you want
Abaqus to assume that surfaces
in
contact slide freely without friction.
?
Select
Penalty
to use a stiffness
(penalty) method that permits
some
relative motion of the surfaces (an “elastic
slip”) when they
should be sticking.
While the surfaces are sticking (i.e.,
),
the magnitude of sliding
is limited to this elastic slip. Abaqus will
continually adjust the magnitude of the
penalty constraint to
enforce this
condition. For more information, see
?
Stiffness
method
for imposing frictional constraints in
Abaqus/Standard” in
“Frictional
behavior,
?
Section 35.1.5 of the Abaqus Analysis
User's Manual
, and
?
Stiffness method for
imposing frictional
constraints in
Abaqus/Explicit” in “Frictional
behavior,
?
Section
35.1.5 of the Abaqus
Analysis User's Manual
.
?
Select
Static-Kinetic Exponential
Decay
to specify static and
kinetic friction coefficients directly.
In this model it is assumed
that the
friction coefficient decays exponentially from the
static
value to the kinetic value.
Alternatively, you can enter test data to
fit the exponential model. (This
Friction formulation
option
also
allows you to specify elastic
slip.) For more information,
see
?
Specifying static and
kinetic friction coefficients” in
“Frictional
behavior,
?
Section 35.1.5 of the Abaqus Analysis
User's Manual
.
Select
Rough
to
specify an infinite coefficient of friction. For
more information, see
?
Preventing slipping
regardless of
conta
ct
pressure” in “Frictional
behavior,
?
Section 35.1.5 of the
Abaqus
Analysis User's Manual
.
?
Select
Lagrange Multiplier (Standard
only)
to enforce the
sticking constraints at an interface
between two surfaces using
the Lagrange
multiplier implementation. With this method there
is
no relative motion between two
closed surfaces until
.
For
more information, see
?
Lagrange multiplier method
for
imposing frictional constraints in
Abaqus/Standard” in “Frictional
behavior,
?
Section 35.1.5 of the Abaqus Analysis
User's
Manual
.
?
Select
User-defined
to define the
shear interaction between the
contact
surfaces with user subroutine
FRIC
or
VFRIC
. For more
information, see
?
User-
defined
friction model” in “Frictional
behavior,
?
Section 35.1.5 of the Abaqus Analysis
User's
Manual
.
6.
If you selected the
Penalty
or
Lagrange Multiplier (Standard
only)
friction formulation,
perform the following steps:
a.
Display the
Friction
tabbed page.
b.
Choose the
Directionality
:
?
Choose
Isotropic
to enter a uniform
friction coefficient.
?
Choose
Anisotropic (Standard
only)
to allow for
different
friction coefficients in the two orthogonal
directions on the contact surface. For
more information,
see
?
Using the anisotropic
friction model in
Abaqus/Standard” in
“Frictional behavior,
?
Section
35.1.5 of the Abaqus
Analysis User's Manual
.
c.
Toggle on
Use slip-rate-
dependent data
if the friction
coefficient is dependent on slip rate.
d.
Toggle on
Use
contact-pressure-dependent data
if the
friction
coefficient is dependent on
the contact pressure.
e.
Toggle on
Use temperature-
dependent data
if the friction
coefficient is dependent on
temperature.
f.
Click the
arrows to the right of the
Number of
field
variables
field to
specify the number of field variables on which
the friction coefficient depends.
g.
Enter the required data
in the data table provided.
h.
Display the
Shear
Stress
tabbed page, and choose a
Shear
stress
limit
option:
?
Choose
No limit
if you do not want to limit the shear
stress that can be carried by the
interface before the
surfaces begin to
slide.
?