Moment Distribution Procedure:

With the knowledge gained in previous sections, we see that the moment distribution method involves the following steps:

(a)        Determination of the fixed end moments because of externally applied loads for all the members (this is given in Appendix A for some common cases).

(b)       Determination of the distribution factors for members meeting at each joint.

(c)        The sum of the fixed end moments at each joint is calculated. Next calculate the balancing moments which is equal in magnitude but opposite in sign to this sum.

(d)       At every joint distribution of balancing moments to each member in the ratios of distribution factors.

(e)        Here carry over half the distributed moments to the other end of each member.

(f)        Repeat the cycle (d) and (e) once it is completed for all the joints of the structure.

This process continues till sufficient accuracy of results is achieved. However, it must be remembered that the process should stop only after a distribution and never after a carry over.

Finally, the sum of all the moments at each joint is added to get the final resulting bending moment. Therefore, we see that the moment distribution is an approximate method of analysis and the degree of accuracy depends upon the number of cycles you perform. However, it can be easily seen that after certain number of cycles sufficient accuracy has been achieved.