Structural ridge beam model

[TTUengr51]

I'm working on a complex heavy timber/conventional framed house and was trying to model a section of the roof to help track loads, etc. The particular portion of this roof has heavy timber rafters that are support by the exterior load bearing walls and a structural ridge beam. The problem I'm having is having the structural ridge act like I would anticipate. On paper, I would treat the ridge as a simple span beam between its two supports. However in my STAAD analysis, the ridge beam appears to be gaining support by each of the adjoining rafters. I've played with releases and end supports and have not been able to get results that make sense.

Has anyone got any ideas on what I can do to force the rafters act as simple span members that would then force the ridge to act as a simple span? Any thoughts would be greatly appreciated.

 

[bylar]

Did your release Fx and Fz at rafter to wall?