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# Direct Analysis Method - Notional load to account for plumbness error

## Direct Analysis Method - Notional load to account for plumbness error

(OP)
Hello,

I am modelling a new facade which is supported by the exterior columns of an existing building. These columns are fully pinned at the top and bottom in the FE-model and hence no translation is allowed.
I want to include the notional loads (0.002 x Yi) on the columns but not sure about two things-
(1) Are notional loads applicable to this situation?
(2) As mentioned above the top support is fully pinned. How can add the notional load when there is a support at the top?

Regards.
Su

### RE: Direct Analysis Method - Notional load to account for plumbness error

Instead of using notional loads, why not model the column as out-of-plumb. Seems an easier way of doing this for such a small / simple model.

### RE: Direct Analysis Method - Notional load to account for plumbness error

Notional loads would be applied in the same manner as other gravity loads on the column regardless of column fixity.

### RE: Direct Analysis Method - Notional load to account for plumbness error

If the FE model has a lateral restraint boundary condition at the top of the column, then the notional load will go directly into the boundary condition and will not cause any moment or shear in the column.... defeating the main purpose of the notional load.

### RE: Direct Analysis Method - Notional load to account for plumbness error

If the top and bottom are both pinned then K=1 and you don’t have to worry about all that mess.

### RE: Direct Analysis Method - Notional load to account for plumbness error

(OP)
Thanks everyone for the responses!

@JoshPlum - Out-of-plumb is an option but that involves some re-work. Therefore I wanted to find out about other possibilities. A colleague of mine suggested to use equivalent member line load on the column instead of applying notional point load at the top of column (which, as pointed out by you, goes directly into the supports). I am considering using this approach.

### RE: Direct Analysis Method - Notional load to account for plumbness error

#### Quote (SuG89)

Are notional loads applicable to this situation?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

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