Hi, i want to model a platform reinforce by stiffeners running across it underneath. What would be the "right way" to do it? What i have done is simply drawing a 2D grillage and extruding them to the desired dimension of the flat bar stiffeners. And i did the same thing for the platform, i drew the section of the platform on top of the stiffeners and extruded them to the desired thickness. What difference would it make if i were to construct the stiffeners using weldments?

Would the different modelling method affect the result of subsequent analysis of the structure? How so?

I tried meshing the platform with shell element, selecting every single surface of the entire platform. The platform are supported by a jacket structure modelled using weldment and meshed using beam elements. Solidworks keep saying that the structure is unstable despite sufficient fixtures. Could it be that i need to specify the contact between the shell and beam element? Even if they are touching each other?(Solidworks automatically bond touching faces?)

Thank you very much.