Design code check for 3D truss/Shell Design

[Anonymous]

Hello,

I am dimensioning trusses that span under concrete plates. I have built a 3D truss model for the trusses and applied the loads as a uniform load on the trusses and a seperate shell design model where the plates are also built in the model. When I perform ¨the design check for the truss elements in the 3D truss model the truss section is ok. However, when I perform the check in the shell model the member is controlled under 6.2.9.1(6) and the element fails even though the element is in tension.

I don't understand why that check becomes relevant when the model is changed? Please find attached both models and the design check. Thank you for your help, Rita

[Artur.Kosakowski · Accepted solution]

When I perform ¨the design check for the truss elements in the 3D truss model the truss section is ok

I have run the check for the same bar as on your picture forcing the location and load case to be the same and in both cases the verifications fail. At this stage I disregarded all instability warnings. 

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