Strut & Tie Modelling - Buckling

[Drapes]

Are there any limitations to using strut and tie modelling from a slenderness and buckling point of view? I cannot find any commentary on this, at least in AS3600.

 

[KootK]

I've never run into anything and I've looked pretty extensively. That, and deflection, still seem to be short comings of the method for the design of certain things.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Drapes]

KootK,

That sounds like a pretty serious shortcoming. If you are designing a deep slender beam using strut and tie, surely the slenderness would need to be accounted for.

Would it be wise to do a separate check on buckling using first principles (for example, designing the strut as a column)?

 

[hokie66]

I don't think the strut and tie method was ever intended for slender elements. It is for non-flexural structural members. Think corbels, pile caps, etc. Chunky things.

 

[KootK]

Strut and tie originated with stocky things but has since be applied to many thing not so stocky. Deep, wallish beams being a great example. And yeah, I'd think that you would have to either resort to a standard sectional check or look at your struts as buckle-able columns in some fashion. If we're speaking of your column transition, no real buckling potential there.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Drapes]

Thank you for the prompt feedback!

 

[WARose]

It's one of those things I've done a check for myself/kept an eye out for. ("Off code" check as I call it.)

 

[Retrograde]

CIRIA Report G002 "The design of deep beams in reinforced concrete" has some discussion on slenderness limits for deep beams.

 

[hokie66]

The way I look at it, if you are applying strut and tie provisions to a wall, the struts just have to be designed as columns, slender or otherwise.

 

[civeng80]

Strut and tie works maybe most times but sometimes like the wall example its difficult to apply and can be over or under conservative.