Disperse loads using dummy area elements?

[Namch]

I'm looking for a sound way to do this.
In case I want to model steel purlins but don't want to model the decking itself, and still I want the load to be dispersed as an area load between purlins (I.e. through a non rigid surface) I tried tinkering with the modifiers but it was not it, sometimes I even got real garbage (reactions were wrong!)
All I could get was something close, asignning a small section with flex material to the shells.
Anybody has clue?

 

[johnbridge231]

You should use a shell with small bending modifiers in order to just transfer the loads to the purlins.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[Namch]

So I figured, but when I did I put in the bending modifiers as 0, do you suggest small as in, what, 0.001 say?

 

[Namch]

And by the way when I put in 0 the results were all wrong, I even got wrong reactions in the supports!