- [Instructor] In this movie, we're going to be looking at
the stress in the part, and figuring out
what that really actually means to us in our design.
So let's go ahead and take a look at what happens,
and before we go further, I want to take this
window out of the center of this thing.
So I'm going to go over here and choose this Cut Extrude
and these two features here, and that one
down there at the bottom, and let's go ahead
and just suppress all those.
So here's our part as it was originally designed,
and I'm going to show you kind of the design process
of how we ended up where we were.
From this point, I'm going to go click on Simulation Express.
It's going to load up.
I've got all the holes defined.
Now, the results aren't quite there 'cause we made 'em
changed for our model, so let's go ahead
and run this this again.
Click on Next, click on Next.
The material is cast alloy steel,
so it's a better choice than gold.
Let's see if that works better.
Go ahead and Run Simulation,
and yes, that looks good,
and click on this von Mises stress.
Now you can see here on the part,
it looks pretty good, right?
You can see right here is kind of the stressed riser,
where it's coming at my yield strength here is 3.4.
Can see the highest stress we're seeing is really 2.3.
So, you can see the factor of safety is already defined here
of 1.4, so it's considerably stronger than it needs to be
which is great.
Generally, you're looking for a factor of safety
about three or better.
So there's a few things we can improve in this model,
or we can reduce the load or adjust other things,
but you can kind of see what's happening
in the model and what's really going on here.
So you can get a lot of good data
from this values up here in the model,
and you can see we've got a lot of areas in here
that are kind of overbuilt, right?
There's almost no stress in this front area here,
and you can see right here in the center of this,
it's this big blue section.
A big blue triangle.
You don't see a lot of stress in there either.
So maybe what we can do is remove
some of that material from the center of the part
right in here, and that'll save us some weight
and casting material, obviously,
when we're going to go and cast this part later on,
and we can also thin out this section out here
to kind of refine our design a little bit better
and that's one of the key things we want to do
when we're doing an analysis of a part.
We're either going to try to figure out if it's
strong enough or if it's too strong,
or we're trying to make it lighter weight.
So if you're doing something for like,
a race car or a mountain bike, something like that,
you're probably trying to reduce the weight
as much as you can.
So what this is telling me is this back plate here
is plenty thick.
We could probably thin that down a little bit,
and it'd be just fine.
It means we can remove material from the
center of the part here, and it also means
I can remove some material from out here.
Now we are seeing quite a bit of stress
right down here at the bottom,
so what that means is we might want to add
a little material to that section of the model
to make that a little bit stronger.
So those are my design recommendations
based upon the von Mises plot
that I'm looking at right here.
Now we're also going to be getting into
displacement and factor of safety in future videos here,
but right now we're just looking at stresses
and what we can do to change or modify the design
to get a more optimized design inside of SolidWorks.
So those are my recommendations.
Now let's go ahead and run it one more time
with a few modifications.
So let's go ahead and exit out of this.
I'll say Yes, and this time I'm going to go back
and I'm going to turn all these back on
and say unsuppress, so I'm going to remove some material
from the center there.
I'm only going to do that one thing
at this point in time, just to see what happens.
Then let's go back into Simulation.
Click on Next, click on Next one more time.
Now we've already defined most of the stuff,
so go ahead and just Run Simulation.
Now it's doing the same simulation
with that material being removed from the center,
and yes it is correct,
and now our factor of safety did
go down a little bit, right?
So we were at about 1.4, now we're about one.
So it's less strong, right, but you can see here,
we're saving a lot of material.
We can even pull this back a little further,
but now we've got a couple of little stress risers here,
but most of this stuff down here,
notice that actually changed.
Remember it was red down here on the bottom
and now it's green most of the way,
and notice that is in this area of about two,
which is almost half of what the yield strength is
in the material, and right down there at the very bottom
where it's kind of peaking up,
and if you zoom in right over here
I think we've got a couple other little areas,
obviously down here, over here you can see that
getting a little bit darker in color,
but it actually made it a little bit nicer plot
by actually removing that material
and you can kind of iterate your design this way.
You can then maybe move this material up a little bit.
You can maybe move this back a little further
so you're not as rigid in this section here
and start refining the design as you go
using these plots and figuring out what happens.
It's pretty easy to iterate like this
just by making a couple quick changes,
and we do have the option to have SolidWorks
just do that for us and refine that design,
and we're going to get into that in just a little while.