why suddenly no load on every member 1

[donnabean]

Hi all,

After I ran non linear static analysis, ETABS showed there were internal force in every member but after steel fram design, there were no trace of force on every member, so basically, those members only take their self weight. Any idea how this happened?
Addtional information: I converted all my load combo into non linear, including 1.4 dead load.
Thanks in advance.

 

[dan97]

I think this also happened to me when I applied releases at the ends of my steel beams. It seems Etabs had already assumed welded connections at beam ends.

 

[johnbridge231]

Did you assign an Automatic Property List to yhe frames instead of a single cross section?

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[donnabean]

Thanks for those replies. I created auto select lists for my beams and columns.
I think I may figure out the reason why it looked like no internal force on members after I ran nonlinear analysis. I chosen step 0 when I tried to see member force diagram for those nonlinear analysis load combinations. If I chosen for example step 5, there would be some force diagram showing.