Moment Distribution vs Software Frame Analysis

[pts1956]

I have been analyzing a simple 4-member, gable portal frame, pinned at each base connection and loaded with uniformly distributed roof loads only(i.e.: no lateral wind or seismic).

Calculated by hand using moment distribution I get a solution for the eave and peak rigid connection internal moments.

All the software analysis programs I've tried so far consistently yield totally different results, where the eave and peak moments appear to be 'swapped' although not of the exact same magnitude as obtained by moment distribution.

Any insight would be greatly appreciated.

 

[EdR]

It's clear there is an error somewhere...If you have two or more programs giving consistent results that are different than your hand calcs then you probably have an error in the hand calcs unless you are making the same error in defining the models to the software....Conversely, making the same error in defining the models could lead to this situation....In any case you need to get a resolution to the problem if this is a real structure as opposed to a class exercise....

Ed.R.