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Re: P-Delta Code Question

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No. Its the sign convention.

Masroor
----- Original Message ----- 
From: "Jake Watson" <jwatson(--nospam--at)utahisp.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Tuesday, April 11, 2006 7:36 AM
Subject: P-Delta Code Question


> I couldn't sleep one night and was reading the code a lullaby.
> Something interesting caught my attention.  AISC and ACI both have a
> very similar coefficient for estimating second-order column effects.
> They both use the variable "Cm" but have a slightly different definition.
> 
>     AISC defines the variable as Cm = 0.6-0.4(M1/M2) (LRFD V3, equation
> C1-3).
>     ACI defines it as Cm = 0.6+0.4(M1/M2)>0.4 (ACI 318-05, chapter 10).
> 
> Please notice the sign in the equation.  Both terms are used to modify
> non-sway frame column moments and go into very similar equations.  Any
> thoughts as to why the signs are different?  Is is a 10 year old typo?
> 
> Jake Watson, P.E.
> Salt Lake City, UT
> 
> 
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