Moment Distribution method developed by Hardy Cross to analyze indeterminate structures like beams and rigid jointed frame with internal hinges also.

Carryover Moment is defined as moment developed or induced at one end due to a moment at anor end. It is useful in calculating stiffness factor and moment distribution for a particular joint.

For a moment applied M at free end with hinged support at anor end, as hinged support cannot carry or resist any bending moment thus carry over moment is zero.

Moment applied at end A would be combinedly resisted by both of support i.e. A and B. However, for given non-prismatic member cross section at support is more and hence offers more resistance to external bending moment. Thus support B resists moment greater than M/2.

The moment distribution method developed by Hardy Cross in 1930 is useful for analysis of indeterminate beams and frames. The method considers flexural effect and ignores any effect caused due to shear and axial loadings.

When a structural member of uniform section is subjected to a moment at one end only, n moment required so as to rotate that end to produce a unit slope, is called stiffness of member. Stiffness is basically a measure of ability of member to resist rotational deformation.

If a unit rotation is to be caused at an end A for far end being fixed supported. Moment of \(\frac{4EI}{L} \) is to be applied at end and hence stiffness for member is said to be \(\frac{4EI}{L} \).