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Re: UBC Chp.23, Div III

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Jason

I agree you can not double dip, but the UBC clause should be a 
little clearer by adding "use Cf=1" or "in leu of a Cf=1.18, a circular 
beam can be....."

Someone with limited timber design experience may unwittingly 
apply both when designing to the letter of the code, not the actual 
intent of the code.

Then again, I have seen plenty of calc's where the only
 factor applied has been the duration factor. 
Wet service, flat use, size, stability etc have been simply neglected.

Peter McCormack

From:           	"Jason Emoto" <jasone(--nospam--at)kpff.com>
To:             	<seaint(--nospam--at)seaint.org>
Subject:        	Re: UBC Chp.23, Div III
Date sent:      	Sat, 13 May 2000 16:33:10 -0700
Send reply to:  	seaint(--nospam--at)seaint.org
Organization:   	http://www.seaint.org

> No, you don't get to double dip.  You can either analyze the member as a
> circular section and bump up your allowable bending stresses by the 1.18
> form factor, or you can analyze the member as a square section with equal
> area.  Either way, it works out the same.
> 
> Jason Emoto
> 
> ----- Original Message -----
> From: "Peter McCormack" <pmac(--nospam--at)realloghomes.com>
> To: <seaint(--nospam--at)seaint.org>
> Sent: Friday, May 12, 2000 11:41 AM
> Subject: Re: UBC Chp.23, Div III
> 
> 
> Jason
> 
> Good point, however, if I was designing a circular member and
> applied the 1.18 form factor to the stress values, the used the
> clause; I think, in effect, I am getting my cake and eating too.
> 
> consider a 8" round beam A=50.3 in^2, Sx=50.3in^3
> square member with equ. area is  7.09 in :>Sx=59.4in^3
> 
> 15% increase in moment capacity, and then apply an 18%
> increase to the allowable bending stress.
> 
> The form factor of 1.18 is to ensure the same moment capacity.
> 
> Does the UBC clarify this point? or am I getting further away from
> the intent?
> 
> From:           "Jason Emoto" <jasone(--nospam--at)kpff.com>
> To:             <seaint(--nospam--at)seaint.org>
> Subject:        Re: UBC Chp.23, Div III
> Date sent:      Fri, 12 May 2000 11:16:12 -0700
> Send reply to:  seaint(--nospam--at)seaint.org
> Organization:   http://www.seaint.org
> 
> > I believe this clause is equivalent to using the form factor (Cf = 1.18)
> > specified for round bending members in NDS section 2.3.8.
> >
> > Jason Emoto
> >
> >
> > ----- Original Message -----
> > From: "Peter McCormack" <pmac(--nospam--at)realloghomes.com>
> > To: <seaint(--nospam--at)seaint.org>
> > Sent: Thursday, May 11, 2000 8:00 AM
> > Subject: UBC Chp.23, Div III
> >
> >
> > Out of interest, does anyone know the background to this clause?
> >
> > "A beam of circular cross section may be assumed to have the
> > same strength as a square beam of the same cross sectional area"
> >
> > Dennis, may be you can enlighten me
> >
> > Peter McCormack
> >
> >
> >
> >
> >
> >
> >
> 
> 
> 
> 
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