Need a book? Engineering books recommendations...

# Interpreting Analysis Results - UPDATE

• To: <seaint(--nospam--at)seaint.org>
• Subject: Interpreting Analysis Results - UPDATE
• From: "Bill Allen, S.E." <T.W.Allen(--nospam--at)cox.net>
• Date: Wed, 29 Dec 2004 08:51:16 -0800

The good folks at Research Engineers have guided me to the section of their technical reference which describes how STAAD.Pro interprets Mxy, p. 3-32.

The user has an option to either ignore Mxy or to use the Wood-Armer equations.

For the top reinforcing, the following quantities are calculated:

Mx1=Mx+abs(Mxy)

My1=My+abs(Mxy)

Mx2=Mx+abs(Mxy^2/My)

My2=My+abs(Mxy^2./Mx)

If both Mx1 and My1 are positive, Mxd=Mx1 and Myd=My1.

If both Mx1 and My1 are negative, Mxd=0 and Myd=0.

If Mx1 is negative and My1 is positive, Mxd=0 and Myd=My2.

If My1 is negative and Mx1 is positive, Mxd=Mx2 and Myd=0.

For the bottom reinforcement:

Mx1=Mx-abs(Mxy)

My1=My-abs(Mxy)

Mx2=Mx-abs(Mxy^2/My)

My2=My-abs((Mxy2/Mx)

If both Mx1 and My1 are positive, Mxd=0 and Myd=0.

If both Mx1 and My1 are negative, Mxd=Mx1 and Myd=My1.

If Mx1 is negative and My1 is positive, Mxd=Mx2 and Myd=0.

If My1 is negative and Mx1 is positive, Mxd=0 and Myd=My2.

Mxd and Myd are then used in lieu of Mx and My for calculations of the required reinforcing.

Regards,

 T. William (Bill) Allen, S.E. (CA #2607) ALLEN DESIGNS Consulting Structural Engineers http://www.AllenDesigns.com V (949) 248-8588 • F (949) 209-2509