Modeling Tanks in Risa 3D 1

[fasboater]

I am trying to model a small tank in Risa (3D 9.0)(small say 72" diameterX72" height). Anyone have any design examples or tech guides that will get started down the right path?

A side note: I am familiar with the high level generation area. I just don’t see where all the loading such as hydrostatic loading is applied.

Thanks

 

[JoshPlumSE]

I prefer to create one "slice" of the arc, apply my hydrostatic loads and then use the copy - rotate feature to copy that around the rest of the 360 degree circle. Heck, if I use the plate generation utlity, I can have the program generate the hydrostatic loading. To me this is the easiest way to handle the loading. But, others will start with the cylinder generation utility. That makes creating the take easier, but the loading has to be done manually which can take awhile.

 

[fasboater]

Josh,

I did create the cylinder first and adding the loading is pretty rough. I am going to try and model your way and see if that is any easier. I think you answered my question though. There is no way to appy a hydrostatic load to a cylinder, well atleast in an easy manner like in the rectanguler tank.

Thanks

 

[prebleg]

This is how I would do it.

Use the cylinder generator to create the cylinder;
Coordinates of Polar Origin; set x,y,z=0
Start Angle-0
Rotation Axis=y
radius=3
Sweep Incs =16
Axis incs = 6
inc. Lentht = 1
Click on "Generate Plates"
Select a material set and thickness
Leave Plate prefix = P
Click ok to generate cylinder

Use the Circular Disk Generator to Make the base
Select Mateiral Set and Thickness (leave plate prefix =P)
POlar Origin: x,y,z=0
Rotation Axis = y
Radius=3
Quandrant Incs. = 4
Radius incs = 10
Click ok to generate plate

Click on Basic Load Cases and create BCL 1 "hydrostatic"

Put the model in the XY plane
Unselect the entire model
Then select the top row of plates
Then click on "Surface Loads for selected Plates"
Leave Dir4ection = z
input the magnitude (calculate this by hand, for water p=.5*62.4/2/1000=.0312ksf
Set Basic Load Case to "1:Hydrostatic"
Click on "Apply Load to All Selected Plates"
Hit Ok to generate loads

Unselect the entire model
select the second row of plates
Repeat proceedure above but increase the magnitude of the load by .0624 ksf

Don't forget to laod the bottom (base) plates

Once you are done do a 2x2 quad submesh on all plates

IN the Global Parameters/Solutin set the "Solver" to "sparse Accelerated"

Apply your boundary conditions, apply any other load and set up your load combinations then solve the model