LATTICE GIRDER DESIGN TO EUROCODE 1991-1-3

The design of cross-sections subject to combined bending, shear and axial force is covered in clause 6.2.10. However, provided the shear force VEd is less than 50% of the design plastic shear resistance Vpl, Rd and provided shear buckling is not a concern then the cross-section need only satisfy clause 6.2.9 for bending and axial force.

Thank you.  I have encounterd a model / analysis level problem now. Kindly suggest me on this one.

I have slimmed down the model now.  increased few load cases.

My query is if you look at axial forces for load case 2 with that  of load case 5, you will find enormous difference in axial forces of the members!!. for example member 396 is having axial force of 58 kN for load case 2 but has 502 kN for load case 5!. The reason I am comparing load case 2 and 5 is - both are of same nature and on same nodes but differ only in magnitude (load case 5 has FY values double than that of load case 2). But this doesnt make sense as the results (axial forces) differ by 1000% !!!

CAn anyone tell me what might have gone wrong?. I have attached the model in here.

Appreciate your help.

Thanks

60489790-SW-CV-CAL-LEY-002.std

Thank you.  I have encounterd a model / analysis level problem now. Kindly suggest me on this one.

I have slimmed down the model now.  increased few load cases.

My query is if you look at axial forces for load case 2 with that  of load case 5, you will find enormous difference in axial forces of the members!!. for example member 396 is having axial force of 58 kN for load case 2 but has 502 kN for load case 5!. The reason I am comparing load case 2 and 5 is - both are of same nature and on same nodes but differ only in magnitude (load case 5 has FY values double than that of load case 2). But this doesnt make sense as the results (axial forces) differ by 1000% !!!

CAn anyone tell me what might have gone wrong?. I have attached the model in here.

Appreciate your help.

Thanks

60489790-SW-CV-CAL-LEY-002.std

The structure is not stable, so the results are not correct. You probably need to change member releases or remove it in some locations so that the structure would be stable and the results would be reasonable.

THANK YOU. I HAVE MODIFIED STRUCTURE NOW.  ANALYSIS IS PERFECT. SINCE SOME END CHORDS OF BOOM ARE FAILING I CHANGED THEIR PROPERTY. I HAVE ADDED A NEW USER TABLE. ALTHOUGH I HAVE FOLLOWED RIGHT SYNTAX I AM GETTING ERROR AS "ABOVE COMMAND IS NOT RECOGNIZED. LINE IGNORED."

CAN YOU PLEASE HELP WITH THIS.

THANKS

MAHESH

PS: I HAVE ATTACHED THE REVISED FILE 

4544.60489790-SW-CV-CAL-LEY-002.std

Words END and CHORD are reserved in STAAD Editor, so you should change the custom section name to something like 1ENDCHORDS. This should take care of the issue.

Hi. Thank you. I have changed it and ran the program again and it says cannot design GENERAL sections. for the members to whom i have assigned usertable properties.
Can you advise me ont his?

The design of general sections is not implemented for BS5950 code. However, this check is implemented for the EN1993-1-1:2005 design code.