Load on projected area - Shells

[fenicerossa89]

I am working on loads such as snow load, and I was wondering how it is achievable to assign a uniform horizontal projected load to a spherical shell (i.e. not applied to the reference surface)?

 

[FEA way]

You can use the surface traction load for that (vector indicating the direction of the load can be specified). And it's also possible to define expression and mapped fields for more advanced load distributions.

 

[fenicerossa89]

Yes, it is possible to use the surface traction load, but the load is always applied to the reference surface and not on its horizontal projection. It is still applied to the surface even using the advanced options to set the loads.

 

[FEA way]

All right, so you want to apply the load indirectly. In such a case you would have to model the projected surface, apply the load to it and then it’s just a matter of connecting it to the actual structure so that the load can be transmitted. You could use contact or tie constraint for that. It would be something like crushing a sphere with a rigid plane.

 

[fenicerossa89]

Since I am studying instability problems, the way you suggested is not applicable. It seems really strange that it is not possible to set a snow load ... simpler and less advanced fem software have this option.

 

[NRP99]

Could you provide more information on what exactly you want to do? May be picture of problem setup. Its difficult to visualize/understand the exact nature of problem without more information or without seeing problem setup.

I am visualizing snow load on spherical roof and checking roof instability with traction load setup is quite straight forward.

 

[PeteTranc]

Yeah. I would also assume that surface traction is the way to go. Anyway what is the advanced option to set the load?