Slenderness Ratio

Please attach the STAAD model here

Cable Tray 5m.STD

Attached is the file. The channels have the same vertical load

The member 21 is failing in slenderness because the nature of force in the member is compression for which the allowable slenderness is 200 and the actual slenderness for the member is around 280. The member 22 has the same actual slenderness but the allowable slenderness limit for that member is 300 as the nature of axial force in it is tensile. So the former fails the slenderness check while the later passes. 

The member 21 is failing in slenderness because the nature of force in the member is compression for which the allowable slenderness is 200 and the actual slenderness for the member is around 280. The member 22 has the same actual slenderness but the allowable slenderness limit for that member is 300 as the nature of axial force in it is tensile. So the former fails the slenderness check while the later passes. 

Dear SYE

Will you pleas elaborate how do get this that above member in compression and below is in tensile. Need your Guidelines to understand.