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Steel silo FEM simulation

Steel silo FEM simulation

Steel silo FEM simulation

(OP)
Hey >

i have a silo design in hand, i already calculated the stresses using janssen equations, but i am having a problem simulation the silo on staad, does anyone here have a document on FEM modeling of Silos or an old model to compare my model with it?

any reference will be helpful :))



ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

RE: Steel silo FEM simulation

Just curious- are you assuming the loads from the product via Janssen equations, and then using FEM on the silo itself? Or using FEM on the product to determine the loading on the silo?

One observation from past experience- in Gaylord & Gaylord's silo book, where they present the Janssen equations, they say, "Use these coefficients." Then two pages over, "Some researchers recommend THESE coefficients..." And if you compare the result, you get completely different numbers. Moral there, is if you're using FEM to determine stresses within the product, I wouldn't expect that to match up to Janssen equations very closely, there appears to be some wide variation of opinion as to how things ought to be done, and whatever approach is used involves a considerable amount of approximation. Also note that stresses within the product can calculate completely differently depending on whether the silo is static or being emptied or being filled.

Second observation from a flow of solids short course a year or two ago: If you want to get anything approaching accuracy, the first thing you do is run tests on the product to see what the properties actually are.

And last observation: The Janssen equations take into account how friction on the sidewalls reduces pressure within the product. But if you have a "small" silo, you can treat the friction on the sides assuming the entire contents is stuck on the sides, and treat lateral forces assuming the entire contents is a liquid. That should be conservative assumptions, and if the silo is "small", you can confirm adequacy without getting too much into the details. For larger silos, this approach is overly conservative, and it is worthwhile going into more detail on the design.

RE: Steel silo FEM simulation

(OP)
Thank you JStephen that was very helpfull, but my issue os the modeling of the silo in STaad Pro and applying the values that came up using the janssin formulas , but i am having a problem decifing what restraints i shoud use.



ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

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