Instability

[Anonymous]

Im working on a 34 m rectangular truss.After running calculations..the results showed "instability" in some members.

Some had yellow color, others had red and yellow.

What do the colors means?

What is the efficiency ratio?

How can I solve this?

[Anonymous]

most likely (this yellow symbol) is to do with member slenderness.  

[Anonymous]

please find attached an image that shows the error..waiting for your feedback

[Anonymous · Accepted solution]

red symbol is because the member is either over capacity (efficiency ratio > 1.0) or deflection is above the limit you specified.  

yellow symbol is what i mentioned before, the element slenderness is above what you have the maximum set to.  

[Anonymous]

Thank you

[Anonymous]

Is there any plug in for AASHTO automatic load combinations ?

[Anonymous]

not sure but the truck database is already in there.  

[Anonymous]

What about reinforced concrete combinations? i.e automatic load combinations conforming to AASHTO LRFD

[Anonymous]

not sure, but doubt it

[Rafal.Gaweda]

No AASHTO LRFD in Robot.