3. Member stiffness and distribution factors

Indeterminate Structures & The Moment Distribution
1

Questions and discussion for this lecture live here. Fire away by hitting Reply below :fire:

2

At 25:30, shouldn’t K = 4EI/L since the adjacent support is a fixed support?

3

Hey @lekaisakaio,
The simplest way to look at this is as follows:

  • if we have rotational resistance provided at both ends of the beam segment, either by a fixed support, or continuity over the support (the first three examples in the summary), the stiffness is 4EI/L.
  • If we only have rotational fixity provided at one end, then the beam segment stiffness is reduced to 3EI/L.

Keep this in mind and you won’t go wrong.

Seán