Moment Distribution
Moment distribution is an analysis method
which can be used to determine the bending moment distribution in an
indeterminate beam.
Analysis Method:
 Calculate stiffness factors for each member

_{ }

 Calculate distribution factors at both ends
of each member

_{
}

 Determine carryover factors at both ends of
each member

COF
= 0.5 for opposite end fixed
COF = 0.0 for opposite end pinned or cantilevered 

Assume all joints are
fixed and calculate fixedend moments for each member.

Balance pinned (to zero) and cantilevered
ends and distribute half the moment to
the opposite end.

Distribute the unbalanced
moments at all other joints to each adjacent member based on the
distribution factor.

Carryover the distributed
moments to the opposite ends of the each member using the carryover
factors.

Iterate steps 6 and 7 until
moment imbalance at each joint approaches zero.

For unbraced frames, solve
equilibrium equations for the restraining force and apply an equal
and opposite force to the frame. Calculate moments due to this
force and combine them with those from the braced frame to get the
total moments.

Example:

Reference Documents:
 Fundamentals of Structural Analysis, West, John
Wiley & Sons.
 Introductory Structural Analysis, Wang & Salmon
 Structural Analysis, Laursen, McGrawHill