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Re[2]: Enercalc Reinforced Concrete Beam design

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     I, too, have never used enercalc. But, irregardless of the direction 
     of the load, the maximum positive moment or negative moment for a 
     fix-fix support with the load indicated is with the absolute value of 
     19.56 K-ft.
     
     Following the premise that the load as indicated was downwards and the 
     resulting value is -19.56, then it would just indicate that the major 
     reinforcement would be at the top since this is in tension and the 
     bottom side is in compression. If, however, the load was upwards, then 
     the major reinforcements would be at the bottom since this is the side 
     in tension.
     
     Following should be the capacities should the material parameters are 
     as indicated:
     
        fc = 3 ksi      fy = 40 ksi     cover = 1.5"     Mu = 17.0 k-ft
        fc = 3 ksi      fy = 60 ksi     cover = 1.5"     Mu = 24.6 k-ft
        fc = 4 ksi      fy = 40 ksi     cover = 1.5"     Mu = 22.6 k-ft
        fc = 4 ksi      fy = 60 ksi     cover = 1.5"     Mu = 32.8 k-ft

     There's a 3.15% differential between your result and my first set of       
     parameters. Could be it be that enercalc is providing a certain percentage 
     below or above theoretical values(like say plus or minus 5%)? And if 
     your value falls within the limit, it says OK?

     Enercalc might answer us.


     Jerome
______________________________ Reply Separator _________________________________
Subject: RE: Enercalc Reinforced Concrete Beam design
Author:  MIME:volnyeng(--nospam--at)COINET.COM at INTERNET
Date:    7/8/98 6:57 PM


>I have never used Enercalc, however, it would seem that the loading may be 
>upwards instead of downwards? Usually down loads are input with a negative 
>sign.  Hope this is the simple answer.
>
>
>-----Original Message-----
>From:	John Armijo [SMTP:421jarmi(--nospam--at)pwcsd.nosc.mil] 
>Sent:	July 07, 1998 10:56 AM
>To:	seaoc(--nospam--at)seaoc.org
>Subject:	Enercalc Reinforced Concrete Beam design 
>
>I am  designing a reinforced concrete lintel over a 12'-0" masonry 
>opening. I have input 2 # 5 Top and Bottom of a 8" wide by 12" deep 
>beam. End conditions are Fixed-Fixed, Seismic Zone 4, 150PCF concrete
>weight, uniform dead load of 1.064 KLF, and #3 ties. All other input values 
>are the defaults.
>
>I have two questions:
>
>1. Which version of the ACI Code is being used? 
>
>2. For the input above I get Maximum Moment, Mu=  -19.56 K-ft and 
>Allowable Moment, Mn/phi= 16.48 K-ft and a note saying, "Beam Design 
>OK". Granted a positive number is larger than a negative number, but my
>concern is that the absolute value, | -19.56 | is greater than the absolute 
>value of | 16.48 | and that the beam design is NOT OK.
>
>Can anyone shed some light on this? 
>
It appears to me that :
     
1. There may be an inadvertant crossover in the language used in defining 
the allowable moment versus the Maximum ultimate moment. Terminology is used 
from both WS and USD in defining the output.
     
2. I would check it by hand using something as archaic as "moment 
distribution"..... A simple check would be a uniform load...
     
3. I'd be tempted to assume that the max moment would be at a support....but 
we all know that assumptions can be the "mothers" of many bad things!!
     
Norb Volny ,PE
Bend ,Or.