Dry Product Storage Design

[andrewdroth]

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.

[AstroJohnPE · Accepted solution]

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.

[andrewdroth]

John,

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,

Andrew/