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Distinguished Contributor
129 Posts
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Registered: ‎06-12-2007
Accepted Solution

Dry Product Storage Design

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03-28-2014 02:11 PM

We are analysing a dry product storage bin with a hopper.


Due to the nature of the product the pressure distribution is not linear, and there is also a vertical traction component due to the product "pulling" on the walls.


I am wondering what the best way to approach a design like this would be.


Ideally we would use some type of variable surface load, and a cylindrical coordinate system. But for whatever reason a critical buckling design scenario cannot be performed with a cylindrical coordinate system.


Right now we are using a spreadsheet to calculate the mean pressure/traction on a particular 11.25 degree section of hopper at different heights to get somewhat accurate results. But we have many loading scenarios, and this is taking a long time to apply all the individual pressures/tractions.


There must be an easier way.


*Expert Elite*
595 Posts
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Registered: ‎08-30-2012

Re: Dry Product Storage Design

03-30-2014 05:48 PM in reply to: andrewdroth


Hi Andrew,


You should be able to use the variable pressure load ("Setup > Loads > Variable Pressure") and cylindrical coordinate system in a critical buckling analysis. Other types of loads (general constraints, forces, and so on) use a local coordinate system by assigning the coordinate system to a surface or node, and the load applied to the same surface or node follow the local coordinate system. The variable pressure load uses the coordinate system assigned to the load; it does not use the coordinate system that is assigned to the surface.


So although the model uses a coordinate system, the analysis itself does not use the coordinate system. So it should work. Whether the software is programmed to work that way is another issue, but give it a try.



John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

Simulation Mechanical user since Dec 1997
Distinguished Contributor
129 Posts
72 Kudos
Registered: ‎06-12-2007

Re: Dry Product Storage Design

03-31-2014 03:27 PM in reply to: AstroJohnPE



Thank you so much.


We just new local coordinate systems were incompatible with CBL and never tried to do it with variable surface pressure.


This is going to save a lot of time.


Thanks again,