Thanks for the advice. That's what I'm doing when I received your mail. I
just need experts' opinions on this. Also, I am browsing through the
computations of my previous office and comparing the results of ETABS and
We can't just trust a computer program even though it is used by 50,000
engineers worldwide. After all they have a disclaimer for it. When a
structure fails, we can't say "there is an error in the program".
Any other opinions?
> From: Christopher Wright[SMTP:chrisw(--nospam--at)skypoint.com]
> Reply To: seaint(--nospam--at)seaint.org
> Sent: Tuesday, May 18, 1999 9:11 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: STAAD Results interpretation
> >I'm trying to figure out the Fx, Fy, Fxy and angle ( for Print Element
> >Forces) and is still in the process of doing so up to now. I hope you
> >help me out on this.
> Although I'm certain the force convention is covered in the docs, this is
> something you should dope out for yourself--it's the only way to verify
> FEA results.
> Run a simple problem with a known obvious answer like an end loaded
> cantilever beam. Print out all the results. The Fx, Fy and Fxy numbers
> should be immediately recognizable from what you know about the force
> distribution in a cantilever. Just to be sure you put in the properties
> correctly, check the end deflection from elementary theory. If the
> effects of orientation aren't obvious, model the beam at a 45 degree
> angle with the coordinate axes. Try it again with gravity loading so you
> can see where that enters in. After you've figured it out for the
> cantilever go back into your real problem and verify your conclusions by
> checking equlibrium with a couple of elements. Draw a free body diagram
> and apply the loads as you found them from your demo problem. Calculate
> the resultant forces and moments and verify that the equations of statics
> are satisfied. If you can't get no satisfaction, either you have the
> blues or you've made a mistake applying the loads, guessed wrong for the
> sign convention or there's a program bug at work (with the likelihood
> pretty much in that order). If you can't do this equiibrium check, work
> at it until you can; otherwise you'll forever be at the mercy of every
> bug or documentation error the program has to offer.
> Christopher Wright P.E. |"They couldn't hit an elephant from
> chrisw(--nospam--at)skypoint.com | this distance" (last words of Gen.
> ___________________________| John Sedgwick, Spotsylvania 1864)