Moment Distribution

What am I seeing?

• Fixed end moments are locked in first, as if every joint were clamped.
• Releasing a joint distributes its out of balance moment to the members meeting there, in proportion to their stiffness.
• Half of each balancing moment carries over to the far end, which creates the next round of imbalance.
• Each cycle is smaller than the last, so the moments converge. Step through and watch the diagram settle.
• A pinned end has a distribution factor of 1, so it is fully balanced every cycle and ends with zero moment.