Hi
I am designing a steel grating with a chequered plate and cross members.
I am trying to model it in 2 ways
1. Neglecting the effect of cross members, i am modeling a composite beam (ISMB with a top plate) for the complete span. I am using BM and deflection values to design the member using composite section modulus. Further, these values matches with my manual calculations.
2. Second way i am trying to model is along with cross beams. But as soon as i apply cross beam, the length of main member reduces (as per staad) and thus there is extreme decrease in the deflection values, bending moment remains unchanged. While there would be some increase in stiffness of structure, there is no way to check such decrease in deflection is correct or not.
If someone can shed light on issues with 2nd way of modeling or can tell ways to overcome this issue in staad, that would be really appreciated.
A sample of what i am trying to do is enclosed as follows (without chequered plate)
Regards.