Transcript
00:02
Simulation pre-check.
00:05
In this video, we will review simulation pre-check and will modify simulation settings.
00:12
In Fusion 360, we want to carry on with our motorcycle rear set model prep.
00:16
If you had any difficulties in setting up the simulation study, then you can upload the supply dataset, motorcycle rear set model prep V11.
00:26
In this design, we have three separate simulation study models and each of those contains a single study with a single load case.
00:34
The first one we have is our bracket and frame mount,
00:37
the bracket and frame mount contains a bracket that has a bonded contact set with our frame mount.
00:43
It has a remote force applied to the pivot points,
00:47
and if we move to our bolted bracket and frame mount, this is a similar setup however, it has bolted connections holding the two pieces together,
00:55
and if we go down to our frame mount only, we have the single frame mount in which we generated our mesh,
01:01
and it's important to note that if you are uploading the version 11 design,
01:05
the mesh will also need to be solved before moving on but local mesh control and the general mesh settings should already be applied.
01:13
From here, we need to talk about pre-check and what pre-check actually means.
01:18
In the solve area we have something called pre-check.
01:22
Pre-check is handy because it lets us know whether or not the simulation study has all of the information it needs.
01:30
If it does, you'll see a green check mark.
01:33
If there is a potential issue for example, if it thinks that it's under constrained, you'll have an orange mark,
01:39
and then if it can't be solved, there's some important information that's missing then it will be red.
01:45
We've done our due diligence so all of our studies are ready to solve,
01:49
but it is important to remember that the degrees of freedom are potentially fixed.
01:55
Potentially fixed doesn't necessarily mean that there's a problem.
01:58
It just means that it's not completely fixed in the environment.
02:02
Once again that's okay because we know that we have restricted its movement in the X direction,
02:08
and then our pin constraints are restricting the movement radially.
02:12
What we would expect to see is that the bracket is going to deform in a manner that is consistent with the load that's applied.
02:19
If we were to look at this bracket and we have a force applied to these two bolt holes, we would expect this to bend into sort of an S Shape.
02:28
Because that load is applied out in space the moment or the torque that's being put on those bolt holes will cause it to deform.
02:36
So now that we know that the pre-check works on all three of these studies, let's talk about ways in which we can make the pre-check not work.
02:44
Let's go back to our bolted bracket and frame mount and let's take a look at our connections.
02:50
The bolted connections between the upper and lower points on our bracket are connecting the two pieces together without the need for a contact set.
02:58
If we were to select the check mark to the left of either of those bolted connections, this will toggle the suppression.
03:06
This means that we're suppressing the bolted connection.
03:09
Because one of them is still in place, we have to suppress both of them before we get a warning.
03:15
Now that we have a warning, let's investigate.
03:18
The pre-check is telling us that it contains one fully unconstrained group.
03:23
This is our pivot point for the foot peg.
03:26
It's completely unconstrained because there's no contact set and there is no bolted connection holding it together.
03:33
Fusion 360 automatically gives you a handful of options in order to fix this.
03:38
You can use automatic contacts, you can create a manual contact set,
03:42
or if you simply want to inspect the problem, you can use the degrees of freedom view.
03:47
Once again, we already know that this bracket is completely under constrained.
03:51
But if we decide to try to solve it anyways, notice that now we have a warning.
03:56
The warning is the same warning that we would see inside of the pre check.
04:00
And if we click Repair, it simply brings us to the pre check dialog.
04:05
Because we know that is the issue, we can untangle the bolted connections to bring them back in the design and now we're ready to go.
04:13
If we go back to our bracket and frame mount, in this case we didn't have a bolted connection but we have our contact sets.
04:21
If we were to modify our contact sets, for example instead of bonded, if we allowed these two to slide and we said Ok,
04:29
now we have a warning and this is because again we have this degree of freedom issue.
04:35
The brackets are still connected together.
04:37
The faces are going to stay but it does allow them to slide, which means as soon as force is applied, this bracket is simply going to move down.
04:45
Once again, we can fix this easily.
04:47
We know what the problem is.
04:48
We simply need to go back and we need to change the slide in contact to bonded.
04:54
Once these two are bonded together, our pre-check is now fine.
04:58
There are a handful of things that will invoke a pre-check warning.
05:03
If we have a situation where we don't have any loads applied and we're not using a structural constraint called prescribed displacement,
05:13
prescribed displacement can be used if you know how much an object should deform but you don't know what the load applied is going to be.
05:20
If we're missing those and there's no load applied and there's no gravity,
05:24
then it'll prompt you to apply a load because there will be a warning because nothing's going to happen to the design.
05:30
If we have an issue with materials, for example some material properties are missing, then we'll likely get an error that we can't solve,
05:37
because the material properties are important to understanding how the stresses are going to be distributed throughout the design.
05:44
But at this point, we already understand all of those things because we've been using the degrees of freedom.
05:50
We understand that we are potentially fixed on our design.
05:54
We understand that we either have a bolted connection or we have some sort of bonded contact set,
05:60
or in the case of our frame mount only we understand that we, in this case we have just a single body,
06:06
so we don't need to worry about multiple bodies being put together.
06:10
So at this stage, we're ready to solve but of course, let's make sure that we do save if we've made any changes before we move on.
00:02
Simulation pre-check.
00:05
In this video, we will review simulation pre-check and will modify simulation settings.
00:12
In Fusion 360, we want to carry on with our motorcycle rear set model prep.
00:16
If you had any difficulties in setting up the simulation study, then you can upload the supply dataset, motorcycle rear set model prep V11.
00:26
In this design, we have three separate simulation study models and each of those contains a single study with a single load case.
00:34
The first one we have is our bracket and frame mount,
00:37
the bracket and frame mount contains a bracket that has a bonded contact set with our frame mount.
00:43
It has a remote force applied to the pivot points,
00:47
and if we move to our bolted bracket and frame mount, this is a similar setup however, it has bolted connections holding the two pieces together,
00:55
and if we go down to our frame mount only, we have the single frame mount in which we generated our mesh,
01:01
and it's important to note that if you are uploading the version 11 design,
01:05
the mesh will also need to be solved before moving on but local mesh control and the general mesh settings should already be applied.
01:13
From here, we need to talk about pre-check and what pre-check actually means.
01:18
In the solve area we have something called pre-check.
01:22
Pre-check is handy because it lets us know whether or not the simulation study has all of the information it needs.
01:30
If it does, you'll see a green check mark.
01:33
If there is a potential issue for example, if it thinks that it's under constrained, you'll have an orange mark,
01:39
and then if it can't be solved, there's some important information that's missing then it will be red.
01:45
We've done our due diligence so all of our studies are ready to solve,
01:49
but it is important to remember that the degrees of freedom are potentially fixed.
01:55
Potentially fixed doesn't necessarily mean that there's a problem.
01:58
It just means that it's not completely fixed in the environment.
02:02
Once again that's okay because we know that we have restricted its movement in the X direction,
02:08
and then our pin constraints are restricting the movement radially.
02:12
What we would expect to see is that the bracket is going to deform in a manner that is consistent with the load that's applied.
02:19
If we were to look at this bracket and we have a force applied to these two bolt holes, we would expect this to bend into sort of an S Shape.
02:28
Because that load is applied out in space the moment or the torque that's being put on those bolt holes will cause it to deform.
02:36
So now that we know that the pre-check works on all three of these studies, let's talk about ways in which we can make the pre-check not work.
02:44
Let's go back to our bolted bracket and frame mount and let's take a look at our connections.
02:50
The bolted connections between the upper and lower points on our bracket are connecting the two pieces together without the need for a contact set.
02:58
If we were to select the check mark to the left of either of those bolted connections, this will toggle the suppression.
03:06
This means that we're suppressing the bolted connection.
03:09
Because one of them is still in place, we have to suppress both of them before we get a warning.
03:15
Now that we have a warning, let's investigate.
03:18
The pre-check is telling us that it contains one fully unconstrained group.
03:23
This is our pivot point for the foot peg.
03:26
It's completely unconstrained because there's no contact set and there is no bolted connection holding it together.
03:33
Fusion 360 automatically gives you a handful of options in order to fix this.
03:38
You can use automatic contacts, you can create a manual contact set,
03:42
or if you simply want to inspect the problem, you can use the degrees of freedom view.
03:47
Once again, we already know that this bracket is completely under constrained.
03:51
But if we decide to try to solve it anyways, notice that now we have a warning.
03:56
The warning is the same warning that we would see inside of the pre check.
04:00
And if we click Repair, it simply brings us to the pre check dialog.
04:05
Because we know that is the issue, we can untangle the bolted connections to bring them back in the design and now we're ready to go.
04:13
If we go back to our bracket and frame mount, in this case we didn't have a bolted connection but we have our contact sets.
04:21
If we were to modify our contact sets, for example instead of bonded, if we allowed these two to slide and we said Ok,
04:29
now we have a warning and this is because again we have this degree of freedom issue.
04:35
The brackets are still connected together.
04:37
The faces are going to stay but it does allow them to slide, which means as soon as force is applied, this bracket is simply going to move down.
04:45
Once again, we can fix this easily.
04:47
We know what the problem is.
04:48
We simply need to go back and we need to change the slide in contact to bonded.
04:54
Once these two are bonded together, our pre-check is now fine.
04:58
There are a handful of things that will invoke a pre-check warning.
05:03
If we have a situation where we don't have any loads applied and we're not using a structural constraint called prescribed displacement,
05:13
prescribed displacement can be used if you know how much an object should deform but you don't know what the load applied is going to be.
05:20
If we're missing those and there's no load applied and there's no gravity,
05:24
then it'll prompt you to apply a load because there will be a warning because nothing's going to happen to the design.
05:30
If we have an issue with materials, for example some material properties are missing, then we'll likely get an error that we can't solve,
05:37
because the material properties are important to understanding how the stresses are going to be distributed throughout the design.
05:44
But at this point, we already understand all of those things because we've been using the degrees of freedom.
05:50
We understand that we are potentially fixed on our design.
05:54
We understand that we either have a bolted connection or we have some sort of bonded contact set,
05:60
or in the case of our frame mount only we understand that we, in this case we have just a single body,
06:06
so we don't need to worry about multiple bodies being put together.
06:10
So at this stage, we're ready to solve but of course, let's make sure that we do save if we've made any changes before we move on.
Step-by-step guide
