Hello everyone.
Welcome to the next session of Answers Workbench Tutorials.
In this session we are solving the fatigue analysis of a ball bearing.
We will start with static structure and double click on it.
Next, I'll go to geometry.
I right click and import the geometry.
I already have the geometry saved with me.
You can create the geometry and then bring it here.
Next, I'll go to model and double click on it.
Now I'll go to coordinate system.
Right.
Click here and insert coordinate system.
I want to know the place where I'm inserting my coordinate system so I will click this inner portion.
And.
So this becomes my point where I'm going to make my origin of the quarter system.
Next, I'll go to connections and I'll check the contacts that are present.
I hold the control button and select each of them.
Next I'll go to type I from Bonded.
I will select No Separation.
I'll again go back to connections.
Right click insert joint.
I have to select the scope first.
I'll select the inner race.
I will select this portion apply.
And again I'll go to scope URL, select this portion and apply.
This is done.
Next I'll go to Mesh.
Right click insert method.
I will select the entire bearing.
I have already chosen the entire body.
If it doesn't get selected at one go, I will again press the control button and hold it and I'll select
the rest of the parts.
Just go in the building and check if anything is left.
Like I can see, all your portion is left.
So I select that do not enter bearing a selected applying.
I will choose the method of meshing as text dominated.
I now go to mesh again insert sizing for this indoor.
And although this I am going to apply an element size of three cm and for the inner balls I'm going
to give another mesh sizing.
I will choose the balls and you can see certain parts are still left.
Also, Don.
And check this part is left.
So all the balls and its cover is selected.
I will click on Apply and I will give the element size of one.
So this completes all the types of meshing.
I'll go to mesh and update.
Machine completes you.
Now I will apply the boundary conditions and go to static structural and insert displacement on this
inner portion.
As we know, the bearing is not supposed to move in the X and Z component, but it is free to give some
kind of reaction in the Y component.
Also, I'm going to apply some pressure on the bearing from the outer end.
So I select the surface and insert pressure.
Let me see.
The magnitude of pressure is ten megaparsec.
I'm giving a random value and see what kind of fatigue I get.
What is a life?
What is a factor of safety?
If this value gives me desirable results such that the bearing is safe for a lot number of cycles,
then we are going to continue with this value.
Or we can reduce this such that we can define in which range my bearing is going to be safe and work
more effectively.
So I'll go to solution right click insert deformation total.
I also want to see the stress on the body.
These two values are generally for a bearing which is under static load condition, which means you
apply the load and you see some amount of result on the body.
But suppose if the load on the bearing is all fluctuating type, which means you apply the load, remove
it, apply and remove it.
So with that, what kind of results you will get is all about the fatigue part.
So I will go to the solution, right click insert fatigue tool and your I will leave the load type as
fully reversed analysis type is stress life and mean stress theory.
I will change it to good material.
Next, I'll go to fatigue tool and insert life and also want to insert the safety factor.
Next, I'll go to solution.
And so on.
Let's see the total deformation.
Let's wait and see the results.
You can see the total deformation maximum value is 0.0 071m.
You can see the unit is written here.
So this shows my total deformation.
Now I'll see my equivalent stress on the body.
This is because of static loading.
I will have a stress of 155 made of steel.
If you go to geometry and see the bearing, each part has a material of structural steel.
We know that for structural steel, the value of stress is going to be max of 86 megaparsec.
So I'll just go back to my engineering data and click on it.
This is my structural steel that I can see here.
We will see the alternating stress on the body.
I will change this interpolation from log log to semi log so I can see this and you can see it is 86
megaparsec.
If you want to see megaparsec, just change it.
See it is 86.2 megaparsec.
So this is my value.
I'll go back to project and update project.
Now I'll go to my model and open it.
I can see the results.
So this gives my results.
Now, because of structural steel, the value should be 86.2 megaparsec.
You can see it is one 55.22 megaparsec.
Also, if I want to see the life, it is six, nine, four, four, 6 seconds.
That is the life of the body.
I will go to safety factor.
I can see that design life is body nine cycles, but my body will only work for these many number of
cycles.
69,000 446.
That is because of the pressure which is applied on the body and it is obviously more than the capacity
of the building.
So the life is going to reduce.
If you want to increase the life of your bearing and you want it to work for more number of cycles,
just reduce the amount of pressure on that building.
So you can see this value is 0.55, which means my body is going to have some breakdown after the number
of cycles that you can see over here, 69,000 for four six.
Now, what we do is we just change this pressure to have a five megapixel and solve this once again.
The deformation.
Is your and this is the stress factor which you can see the 77.609.
Now, this is less than 86 gigapascals for structural steel, which means my body is going to be more
safe under this amount of pressure.
If I go to life, I can see the number of cycles for which it can work.
With your number of cycles is 1 to 6 cycles.
It was designed for one or two generation mine cycles, which means my life has definitely improved
and you can see all your safety factors 1.11 When the value is more than one, it indicates that your
body will have a little longer life.
It will definitely wear after some point and break down.
But the life is going to be a little more.
So with this, I end the session.
I hope you have understood how to analyze a bearing and interpret the results for it.
If you have any doubts, please write to me in the comment section.
See you in the next session with another analysis.
Thank you.