Return to index: [Subject] [Thread] [Date] [Author]

Re: UBC Chp.23, Div III

[Subject Prev][Subject Next][Thread Prev][Thread Next]
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
>
>
>
>
>
>
>