About Gravity and Mass

Altair Forum User

Hey 
Radioss does not scale the Gravity Load with the density of my Elements. The applyed load is about 50,000x greater. Is there some setting I have to check.

In my project I alwaso use the same Unit system: mm  s  ton  N/mm^2  ton/mm^3

 

 

Altair Forum User

Hi @MuchMore

 

I am sorry, Please correct me If I am wrong,

 

You are trying to scale the model and you are expecting the Gravity value should scale along with the model, Is that correct?

 

If yes, no, RADIOSS will not scale Gravity load. 

 

If you are talking about scaling of Gravity load visually, you can do that using Utility>>BCs Manager>> Review the Gravity load and increase the Lable Scale. 

Altair Forum User

No that is not what I ment.

My part has the dimensions 60x15x3.3 density is set to 2.7E-09,  E-Modul 69500. My simulation time is between 10-20.
With those setting a am suppost to set the Gravity to -9810 (mm/s^2)
However when I start the simulation my part was behaving like jello.
My first thought was I miscalculated the density. But as I was playing with the setting I noticed that it does not matter how low I set the density. The applyed force only scaled with the set Gravity curve.
Within the  *000.out file I checked the total Mass of my part and it was calculated correcly to ~8g.
 

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Altair Forum User

@MuchMore

 

Not, it is not possible to automatically set a scaling between two parameters. 

 

It is up to the user to maintain the unit consistency.

Altair Forum User

Can you elaborate. Because I am certain that a lump of steel should receive a higher gravitational load that a thin pice of foam.
Also what will be the correct unit consistency?  As written above I checked my entered units over and over and can't find my error.