Define generative design conditions

00:02

Define generative design conditions.

00:06

After completing this video, you'll be able to

00:08

define structural constraints, define structural loads,

00:12

create a clone of structural loads and a clone of a load case

00:18

in fusion 3 60.

00:19

We want to carry on with our internal combustion engine

00:22

dash GEN design set up from the previous video.

00:25

At this point,

00:25

we have the obstacle and preserved geometry selected

00:28

and we're gonna begin setting up our design conditions

00:32

to start.

00:32

Let's hide our obstacle geometry and focus our

00:35

attention just on the cylinders on the screen.

00:37

This is going to represent the lower portion of the

00:39

connecting rod and the upper portion of the connecting rod.

00:43

Whenever we start applying loads and constraints to a design,

00:46

it's always important.

00:47

We understand all of the loads and constraints that apply to this design.

00:51

Throughout this course,

00:52

we're not going to be talking about all the

00:54

loads and constraints that apply to the connecting rod,

00:57

but instead focus our attention on how to apply them.

01:01

So to get started,

01:02

we want to begin by taking a

01:03

look at our design conditions and structural constraints

01:07

note the different constraint types that we can apply

01:10

fixed pin, frictionless and remote.

01:14

It's important to understand what each of these do.

01:17

And you can always expand the information in fusion 360 select

01:21

more information to navigate to the help file on the web.

01:26

For this example,

01:27

we need to understand that the fixed constraint and the pin constraint when

01:31

all three directions are locked down will produce the exact same result.

01:35

Only when one of these directions is unlocked,

01:38

will the pin constraint give us a different result.

01:41

For this example, we're gonna be using the fixed constraint

01:44

at the inside portion of the lower cylinder.

01:47

While this may not be the realistic scenario for a

01:51

connecting rod because it's never mechanically locked at the bottom.

01:54

We need to understand that we're isolating this

01:57

position or this object inside of our assembly.

02:01

We're gonna be using the fixed constraint at the base locked in all three axes X Y and Z

02:08

to prevent any rotation or translation.

02:11

This means as we apply loads to the upper portion of the connecting rod,

02:15

we can rotate them and apply them at various angles.

02:19

Once again,

02:20

understanding how the loads and constraints apply to your

02:23

own designs are going to be an important consideration.

02:27

After we applied a constraint,

02:29

we'll note that there is a lock icon listed at the bottom.

02:33

If we happen to change the constraint to be unlocked in one direction,

02:37

we would notice that there would be a change in the icon to unlocked.

02:41

This is an important distinction to note on the screen

02:44

as you're setting up your own loads of constraints,

02:48

I'm gonna rename load case one by selecting it and then left clicking again.

02:52

And I'm gonna call this T DC for top dead center.

02:56

Next, we want to apply a load to the top portion of our connecting rod.

03:01

Once again, just like constraints, we have multiple load types that we can apply.

03:06

We need to look for the best option for what our situation calls for

03:11

a force is going to apply a force evenly across the selection.

03:15

The pressure is going to apply a pressure on the selected faces.

03:20

For our example, the bearing load is going to give us the best scenario.

03:25

And this is because a bearing load takes a look at a

03:28

cylindrical face and it will apply the load in a parabolic distribution.

03:33

This means that the bottom center of the face will have the highest load

03:36

and it will diminish as it gets closer to the sides of that cylinder,

03:41

none of the load will be applied to the top of the cylinder.

03:44

Now,

03:44

this is a big distinction that we need to understand

03:47

when applying these loads to a cylindrical part like this.

03:51

We also have remote forces and remote moments.

03:54

These allow us to apply a force or a moment that

03:57

is somewhere out away from the object that we're designing.

04:01

This is important for certain types of designs to prevent us

04:04

from having to create complex systems of different connected preserved geometry.

04:10

When really a remote force or a remote moment will be the best option.

04:14

Once again,

04:14

it's important to note that certain features like the previewer might

04:18

not work depending on which types of loads you use.

04:21

For our example, we're going to be using the bearing load.

04:25

We want to select the inside of the cylinder and we

04:27

want to take a look at the graphic on the screen.

04:30

We can see that there are arrows that are currently pointing up.

04:33

And I'm gonna rotate these so that they point down at minus 180 degrees.

04:39

For this example,

04:39

we're going to be using 7000 newtons as the force applied in this position.

04:45

We're gonna say, OK.

04:46

And now we want to create a clone of this load case,

04:49

the fixed constraint on the bottom of the connecting rod is going to stay the same.

04:53

But each time we create a new load case, we want to adjust the bearing load

04:58

rather than reapplying the fixed constraint and the bearing load every time

05:01

we can simply right click on this load and we can create a clone or a copy of it.

05:07

When we clone the load case, notice the name is T DC one.

05:12

And if we activate it,

05:13

the loads underneath will be our bearing load and our fixed constraint.

05:18

Let's go ahead and rename this T DC.

05:21

And we're gonna call this five

05:23

what we're gonna be doing is adjusting the load angle at

05:27

five degrees by right clicking and editing our structural load.

05:32

We're gonna change this from minus 1 80 to minus 1 75. We'll say, OK,

05:37

and we're gonna take T DC right click and create another clone

05:42

will activate the second clone

05:45

and we're gonna call this

05:47

P five for plus five.

05:50

Then we can expand our loads,

05:52

editor bearing load.

05:54

And this time we're going to go from minus 1 80 to minus 1 85.

05:58

The positive and negative directions really aren't

06:01

going to matter in our naming conventions

06:03

as long as we follow suit by moving them in the same direction.

06:07

So what we're gonna be doing is we're going to modify T DC P five by creating a clone.

06:14

We're gonna edit the name

06:16

this time we're gonna do P 10

06:20

and we're going to modify our load to increase that another five degrees.

06:24

So instead of 185 we'll be at 190

06:27

we're gonna do the same thing for the five degree, right click and clone it.

06:32

We're gonna activate it

06:35

and we're gonna change this to 10 degrees.

06:40

Once again, we're going to expand our loads,

06:43

we're gonna edit our bearing load and we're gonna add another five degrees.

06:50

We're gonna keep following this process by cloning specific load cases.

06:55

So now that we have 10 degrees,

06:57

we're gonna go up to 15

07:03

and once again, we'll edit the load case.

07:06

Now, instead of minus 1 70

07:08

we'll be at minus 1 65.

07:12

Then we're gonna take the P 10,

07:15

we'll clone it,

07:16

activate it.

07:17

And this will be P 15.

07:22

Once again, we'll expand the loads

07:25

span the load case and we'll take away another five degrees.

07:31

So at this point, we've gone from top dead center,

07:34

we've got five degrees, 10 degrees and 15 degrees in both directions.

07:39

we're gonna carry this on.

07:40

But instead of doing it every five degrees, now we're gonna jump up to 25 degrees.

07:45

The loads that you apply to your specific cases are going to

07:49

be determined based on how that design interacts with its environment.

07:53

So in this case, I'm not gonna do every five degrees,

07:55

but just to simplify the process, we're gonna go uh to 25 degrees from 15.

08:00

This means that instead of 1 95

08:03

we're gonna be at minus two oh five,

08:06

we're gonna do the same thing for T DC 15,

08:10

we clone it,

08:12

we activate it,

08:14

we'll change it to 25

08:17

and we'll edit the load.

08:20

So instead of minus 1 65 we'll be at minus 1 55.

08:25

Now, we're gonna do this one more time by cloning this,

08:29

we're going to activate it

08:31

and this one is going to be T DC 30.

08:34

Now, as I mentioned,

08:34

we're not looking at all of the load cases that apply to the connecting rod,

08:39

but something that we should consider is as the piston moves through its travel,

08:43

not only does the angle change, but the load is going to change as well.

08:48

So at this point, I'm gonna reduce the load down to 3000.

08:53

It would be realistic to assume that the maximum force applied

08:57

to the piston happens in the top 5 to 10 degrees.

09:01

Once we get down into the 30 degree range, the load is diminishing quite rapidly.

09:07

So at this point,

09:08

what we're gonna be doing is we're gonna be cloning this last load case,

09:11

we're gonna name it P 30.

09:16

And we're gonna go ahead and edit the last load case

09:21

or add another five degrees

09:23

and change the magnitude to 3000.

09:26

So in this instance,

09:28

we only were dealing with a single bearing load and a single constraint.

09:32

So cloning these load cases did save us time,

09:35

but the time is going to be exponentially saved.

09:38

The more load cases that you have and the more loads and constraints you apply.

09:43

So as you begin to create complex

09:45

loading environments for your generative designs,

09:48

consider using the clone option on your load cases,

09:51

all of these load cases will be used and applied to each generative solve.

09:57

So one single iteration of that solve will take a look at each

10:00

one of these specific load cases in order to generate its results.

10:05

Before we say this,

10:06

let's take a look at the precheck and

10:09

note that we're still missing some information.

10:11

There are some defaults in here but note that the milling head diameter is too large.

10:16

This is a warning that is going to be

10:18

present until we make our changes to manufacturing constraints.

10:22

At this point,

10:23

we can make sure that everything is saved before moving on to the next step.