Simulate multi-body interactions using Event Simulation.
Transcript
00:04
Event simulation produces results common to other structural
00:07
analyses such as displacements and various stresses.
00:11
However, it is not limited to static conditions or elastic materials.
00:15
Nonlinear material behavior is supported,
00:18
large deformations and free body motion are supported as well
00:22
as contact interactions that can change throughout the simulated event.
00:26
Velocity and acceleration results are available.
00:29
You can simulate part breakage through the automatic elimination
00:33
of elements from the mesh at strains above.
00:35
A specified value.
00:37
Event simulation is a fully dynamic analysis
00:39
tool taking into account mass velocity acceleration,
00:43
damping and inertial effects
00:45
as such.
00:46
It is useful for analyzing impacts forming
00:49
operations and many other dynamic events.
00:52
This model is a two part snap fit assembly and
00:56
we simulate the insertion of one part into the other.
00:59
The locking fingers deform as they're pressed
01:01
into the middle hole of the stationary part
01:04
contact allows the parts to slide along and separate from each other freely
01:08
but prevents penetration.
01:10
Let's look at the process of setting up and solving the analysis.
01:17
Create a new study, choosing the event simulation analysis type,
01:22
then
01:23
click this icon to access the study settings.
01:27
Let's set a total event duration of six milliseconds
01:31
and choose to save 12 sets of incremental results.
01:35
We'll define an absolute mesh size of three millimeters which will produce
01:38
two elements through the main body thickness of the two parts.
01:43
We're not concerned about stresses in the stationary body and we
01:46
can reduce the solution time by specifying that this body is rigid
01:50
stresses and strains are not computed for rigid bodies
01:56
substitute a stronger material for the A BS
01:58
plastic previously defined in the model workspace.
02:04
We'll use nylon 66 for both parts
02:10
apply a constraint to the stationary part.
02:15
Notice that it is recognized as a rigid body
02:17
and three rotational degrees of freedom are supported.
02:20
In addition to the translational ones,
02:22
we'll keep the default action all degrees of freedom constrained.
02:27
Apply a prescribed translation of 10 millimeters in the minus
02:30
Z direction to the front face of the moving part.
02:34
This translation pushes the parts together,
02:37
leave the X and Y components active too but keep the magnitude at zero.
02:41
This technique prevents X and Y motion without
02:44
having to apply a separate fixed constraint,
02:47
define a multiplier curve to specify how the displacement varies over time.
02:52
During the simulated event.
02:56
This curve decelerates the part as it approaches
02:59
the fully inserted position for a smooth action.
03:06
In the first two milliseconds,
03:08
the part moves six millimeters 0.6 times
03:11
the translation magnitude of 10 millimeters.
03:14
Therefore, the velocity during this period is 3000 millimeters per second.
03:19
We'll need this velocity in the next step.
03:24
Next, we apply an initial linear velocity to the moving part.
03:28
This action prevents the shock of instantaneously accelerating
03:32
the part at the beginning of the event.
03:34
Essentially, we're saying that the part is already in motion.
03:37
At the beginning of the simulation.
03:39
The speed as we've just determined is minus
03:46
automatically generate the contact sets.
03:49
We'll keep the default global separation contact setting,
03:52
but disable self contact.
03:54
We don't expect any part to deform enough to contact itself
03:57
and not checking for self contact will shorten the solution time.
04:02
Ensure that the select through option is enabled under selection filters.
04:07
In the next step, we need to select hidden faces of the model
04:11
to provide smooth contact surfaces and a more accurate contact solution.
04:16
We need a local mesh control in the contact regions.
04:19
Also a finer mesh all over the locking fingers will provide better stress results.
04:24
Let's set the size at one millimeter or one third of the global mesh size.
04:30
Select all of the faces of the locking fingers
04:33
and the middle hole in the stationary part.
04:36
Then apply the mesh control.
04:39
The study is ready to solve
04:44
when the solution finishes. The von mises stress results appear
04:48
first.
04:49
Let's take a look at the mesh to see the local refinement we defined
04:53
and hide the stationary part for a better view of the locking fingers.
04:57
Now take a look at the displacement results.
05:02
We'll display a chart of this result versus time.
05:05
Notice that the displacement curve matches
05:07
the translation multiplier curve we define.
05:09
During the study setup,
05:12
we can create a slice plane for a better
05:14
view of the part interaction and locking finger stresses,
05:18
choose a reference face and drag the slice plane to the desired location.
05:22
You can also specify an exact offset
05:25
here.
05:25
An offset of 6.35 millimeters places the slice plane in the exact center of the part
05:33
from the browser hide the sliced plane so that it doesn't obscure the contour plot
05:40
we're interested in the bending stresses and the locking fingers to
05:43
make sure they won't break due to excess stress during assembly.
05:47
The normal ZZ stress tensor represents the bending stresses in the fingers,
05:52
drag the step slider to see how the stresses vary during the event.
05:57
Finally
05:58
animate this result to watch the entire insertion event.
06:02
There are 13 steps. One being the initial condition plus 12 calculated steps, a
06:07
setting of 26 steps here gives us two animation frames per step.
06:13
Notice how the fingers oscillate in the last
06:15
millisecond of the event after they snap into place
06:19
analysis of many such assembly disassembly impact and
06:23
deformation events is possible using event simulation.
00:04
Event simulation produces results common to other structural
00:07
analyses such as displacements and various stresses.
00:11
However, it is not limited to static conditions or elastic materials.
00:15
Nonlinear material behavior is supported,
00:18
large deformations and free body motion are supported as well
00:22
as contact interactions that can change throughout the simulated event.
00:26
Velocity and acceleration results are available.
00:29
You can simulate part breakage through the automatic elimination
00:33
of elements from the mesh at strains above.
00:35
A specified value.
00:37
Event simulation is a fully dynamic analysis
00:39
tool taking into account mass velocity acceleration,
00:43
damping and inertial effects
00:45
as such.
00:46
It is useful for analyzing impacts forming
00:49
operations and many other dynamic events.
00:52
This model is a two part snap fit assembly and
00:56
we simulate the insertion of one part into the other.
00:59
The locking fingers deform as they're pressed
01:01
into the middle hole of the stationary part
01:04
contact allows the parts to slide along and separate from each other freely
01:08
but prevents penetration.
01:10
Let's look at the process of setting up and solving the analysis.
01:17
Create a new study, choosing the event simulation analysis type,
01:22
then
01:23
click this icon to access the study settings.
01:27
Let's set a total event duration of six milliseconds
01:31
and choose to save 12 sets of incremental results.
01:35
We'll define an absolute mesh size of three millimeters which will produce
01:38
two elements through the main body thickness of the two parts.
01:43
We're not concerned about stresses in the stationary body and we
01:46
can reduce the solution time by specifying that this body is rigid
01:50
stresses and strains are not computed for rigid bodies
01:56
substitute a stronger material for the A BS
01:58
plastic previously defined in the model workspace.
02:04
We'll use nylon 66 for both parts
02:10
apply a constraint to the stationary part.
02:15
Notice that it is recognized as a rigid body
02:17
and three rotational degrees of freedom are supported.
02:20
In addition to the translational ones,
02:22
we'll keep the default action all degrees of freedom constrained.
02:27
Apply a prescribed translation of 10 millimeters in the minus
02:30
Z direction to the front face of the moving part.
02:34
This translation pushes the parts together,
02:37
leave the X and Y components active too but keep the magnitude at zero.
02:41
This technique prevents X and Y motion without
02:44
having to apply a separate fixed constraint,
02:47
define a multiplier curve to specify how the displacement varies over time.
02:52
During the simulated event.
02:56
This curve decelerates the part as it approaches
02:59
the fully inserted position for a smooth action.
03:06
In the first two milliseconds,
03:08
the part moves six millimeters 0.6 times
03:11
the translation magnitude of 10 millimeters.
03:14
Therefore, the velocity during this period is 3000 millimeters per second.
03:19
We'll need this velocity in the next step.
03:24
Next, we apply an initial linear velocity to the moving part.
03:28
This action prevents the shock of instantaneously accelerating
03:32
the part at the beginning of the event.
03:34
Essentially, we're saying that the part is already in motion.
03:37
At the beginning of the simulation.
03:39
The speed as we've just determined is minus
03:46
automatically generate the contact sets.
03:49
We'll keep the default global separation contact setting,
03:52
but disable self contact.
03:54
We don't expect any part to deform enough to contact itself
03:57
and not checking for self contact will shorten the solution time.
04:02
Ensure that the select through option is enabled under selection filters.
04:07
In the next step, we need to select hidden faces of the model
04:11
to provide smooth contact surfaces and a more accurate contact solution.
04:16
We need a local mesh control in the contact regions.
04:19
Also a finer mesh all over the locking fingers will provide better stress results.
04:24
Let's set the size at one millimeter or one third of the global mesh size.
04:30
Select all of the faces of the locking fingers
04:33
and the middle hole in the stationary part.
04:36
Then apply the mesh control.
04:39
The study is ready to solve
04:44
when the solution finishes. The von mises stress results appear
04:48
first.
04:49
Let's take a look at the mesh to see the local refinement we defined
04:53
and hide the stationary part for a better view of the locking fingers.
04:57
Now take a look at the displacement results.
05:02
We'll display a chart of this result versus time.
05:05
Notice that the displacement curve matches
05:07
the translation multiplier curve we define.
05:09
During the study setup,
05:12
we can create a slice plane for a better
05:14
view of the part interaction and locking finger stresses,
05:18
choose a reference face and drag the slice plane to the desired location.
05:22
You can also specify an exact offset
05:25
here.
05:25
An offset of 6.35 millimeters places the slice plane in the exact center of the part
05:33
from the browser hide the sliced plane so that it doesn't obscure the contour plot
05:40
we're interested in the bending stresses and the locking fingers to
05:43
make sure they won't break due to excess stress during assembly.
05:47
The normal ZZ stress tensor represents the bending stresses in the fingers,
05:52
drag the step slider to see how the stresses vary during the event.
05:57
Finally
05:58
animate this result to watch the entire insertion event.
06:02
There are 13 steps. One being the initial condition plus 12 calculated steps, a
06:07
setting of 26 steps here gives us two animation frames per step.
06:13
Notice how the fingers oscillate in the last
06:15
millisecond of the event after they snap into place
06:19
analysis of many such assembly disassembly impact and
06:23
deformation events is possible using event simulation.
Want to try this? In the Fusion Data Panel, open the start file from Samples > Basic Training > 11 - Simulation > SnapFit.
For more, see Dynamic event simulation.
