stress analysis on imported part

[Anonymous]

Hi,

Im trying to do (and experimenting with) a stress analysis. I have some basic frame parts simulating the base frame, the frame parts i am running the test for, and an imported part (pump) i am attempting to use as weight.

See the attached image:

Black for weight,

Blue for basic frame parts,

Red for frame parts i attempt to analyse.

When i prep for running the test the mesh fails to create on the imported part (pump). It is a solid, but also a rather complicated shape in comparison to the frame parts. The pump also does have a given mass on the physical tab in its iproperties.

In my head this would be solved by somehow making the pump a rigid, non-deforming body with mass. Hoping it can just exert its weight on the frame parts its standing on so i can test it somehow.

If anybody has an idea how i could make this happen or knows a better way to analyse the frame parts, let me know!

--> Mees

[TheCADWhisperer]

Are you testing the pump or are you testing the frame?

Why do you even need the pump in the assembly?

[Anonymous]

I attempt to test the frame, by applying a gravitational force to the pump. I am not entirely sure how the "force" is applied when i place one with a force command on the top side of the frame parts. I'm guessing it wil evenly distribute the force across the entire surface, which means i get incorrect results.

The only reason to include the pump for this matter is because i think it will yield more accurate results, because of the contact area of the pump. If you have an idea how i might do it without pump, let me know!

[johnsonshiue]

Hi! I don't think overridden mass would be considered in FEA. It is because FEA deals with material properties and the geometry directly. The overridden mass is just an attribute. FEA does not use the value to compute.

If you have to force the mass, you will need to adjust material density so that the total mass becomes close to the overridden value.

Many thanks!

[S_May]

Hi @Anonymous,

you write in the power of Analysis...

[JDMather]

Spit face for area of contact. 

[Anonymous]

This is 100% true and very important to consider.  I've discovered this the hard way....The over-ridden mass of a part will NOT carry over to an FEA when a gravity load is applied.  For example, if you were to force the part to weigh 20,000 lbs. and apply a gravity load, the load will not be as expected.  Instead, it will behave as if no over-ridden value was applied (ie, the mass of the part prior to you manually entering a value). As @johnsonshiue has mentioned, you need to create a custom material with a very high density to get close to the weight you require prior to applying gravity. 

[Frederick_Law · Accepted solution]

You can use a very high strength material for the pump, ie ceramic or create a new material.

Instead of using gravity, apply a load on top of the pump for the weight you need.

As long as the pump doesn't deform, load on the frame will be good.

Another way is model the contact pads from pump to frame and apply load on them.

[Anonymous]

I am going to use this work around. I had hoped there would be a different way to do it, but alas. 

Thanks to all of you for the information on how the inventor FEA works!

Greetings,

Mees

[JDMather]

---

@Anonymous wrote:

... I had hoped there would be a different way to do it, but alas. 

---

You will be meshing geometry that you do not need in the analysis.

This is not the correct way. 

There is a better way.  

[Anonymous]

i didnt mean i"m going to mesh the entire pump, ill probably make a very rigid surface and apply a load on top of it equal to the pump's weight.