Eccentric load on column
Eccentric load on column
(OP)
Just a quick question about eccentric loading on a pinned-pinned column.
My understanding was that if you had a column with an eccentric load P. If you took a Free body diagram half way down the column this eccentric load was cause a moment (P x e).
e being the eccentricity. But would this not cause a the column to bend increasing e hence increasing the moment which again increases e and so on?
Should that mean that a column could not support any load at all!... Doesnt seem right
Cheers!
My understanding was that if you had a column with an eccentric load P. If you took a Free body diagram half way down the column this eccentric load was cause a moment (P x e).
e being the eccentricity. But would this not cause a the column to bend increasing e hence increasing the moment which again increases e and so on?
Should that mean that a column could not support any load at all!... Doesnt seem right

Cheers!






RE: Eccentric load on column
If the load is less than the buckling load then the additional moment caused by the deflection will be less than the reaction moment caused by the deflection, so the total deflection will be finite.
This is the basis of the theory of buckling.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Eccentric load on column
or do you have a lateral couple (which'd make is a beam column) ?
also i think the FBD assumptions are wrong, 'cause you have not accounted for column bending. look up "secant equation for columns with offset loads".
Quando Omni Flunkus Moritati
RE: Eccentric load on column
But I am not sure I am addressing your question.
DaveAtkins
RE: Eccentric load on column
Quando Omni Flunkus Moritati
RE: Eccentric load on column
Like your latin sub-signature. I love the RG show.
But did you ever see this?: http://www.vocabulary-lesson-plans.com/latin-phras...
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RE: Eccentric load on column
Above and below the point of application, the moment at any point along the column is the horizontal reaction multiplied by the distance to the reaction.
If the point of application is not at the mid-height of the column, there will be a small horizontal deflection. If P is huge and e is small, the deflection could conceivably add a significant amount to e, but it is unlikely. The calculation is not difficult.
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Eccentric load on column
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Eccentric load on column
Looking back, I see there is just as good a case for your interpretation and answer.
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Eccentric load on column
RE: Eccentric load on column
DaveAtkins