Patran:gravity load simulation

[sneve]

Hi everybody,
I´d like to ask how to simulate a gravity load in MSC.Patran.

In my model, there is a simple container made of shell Quad 4 elements with composite properties. Container is full of water which is simulated by solid hex8 elements. These have an isotropic properties with a small E, and related density.
The structure is loaded just by the water mass. How can I simulate it?
(I can assign the gravity acceleration to these elements but how to make it related to the volume of elements?)
Thanks,
janek

 

[Onda]

Do not use solid elements inside your tank. Instead, just apply a pressure that is varying linearly with height.
To do so, you should make a spatial field and use the field for the intensity of the pressure.
If the water level is @ 2000mm in Z then the field should be (AbS(2000-'Z)+(2000-'Z))/2*9.81*0.000001 (using mm-kg-sec)
in this way You don't apply a negative pressure on elements higher then water level.
Be sure that all yours elements have congruent normals.

Onda