Wednesday, February 23, 2011

COLUMN CAPACITY CALCULATOR - SAWN - COOL

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Here is a Column Capacity CALCULATOR ... http://courses.cit.cornell.edu/arch264/calculators/example7.1/index.html

Totally COOL! ... note the disclaimers.

Me thinketh that it is for CENTRIC loading ... in fact, IT IS ... here's a quick check.

If you put in a length of, say, 0.1 ft, the C_P should be essentially 1.00.  Further, for Normal load duration, not hot, not wet, etc. ... we should get a column capacity of ...

(follow along!)

Let's consider a 6 x 6 `Post and Timber' column of dims 5.5 by 5.5 ...

A = 5.5 x 5.5 = 30.25 sq. in.

Trying DF-L No. 2 ... Fc = 700 psi

All the C's go to unity

So, Fc' = 700 psi times 1's ... = 700 psi.

P_allowable = Fc' A = Fc A ...


So, P_allow = 700 psi (30.25 sq. in.) = 21,175 lb.

Behold, that's what the `calculator' gives us.

Load is indeed assumed to be dead center.

If we allow the load to drift off center ... the capacity will be LESS!

Doc

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