Beam to beam moment joint

Question

Hello Community, 
 I have doubt regarding the beam (secondary) to beam (primary) moment connection (no releases defined). 
 1) How does staad calculate the end moment transferred from secondary to primary beam for moment connection? 
 Of-course it will not be same as the beam with end fixed supports, but it is very low (reduced value) as compared to that with fixed support. 
 2) Also in torsion check Staad considers the reduced value rather than the fixed support value! 
 May i know the logic behind it? 
 Thanks in advance.

Sye · Answer

In a finite element model, the way the load is distributed between members, depends on their relative stiffness. For example let us consider how the major axis moment for the secondary beam is transferred. If the secondary beam has a fixed support defined at it&rsquo;s end instead of the support being the primary beam, the moment that would be transferred to the support would be the fixed end moment. However when the primary beam is the support, the moment is resisted by the rotational stiffness of the primary beam at the location where the beams connect. This stiffness would generally be less compared to the rotational stiffness offered by a fixed support. So the major axis moment developed in the secondary member at the connection may be less and applied loads may follow a different load path.