The original propped cantilever beam can be
split into two simply supported beam cases:
case 1 – simply supported beam with uniform load
case 2 - simply supported beam with moment at the support
In this approach, the moment support at B is removed, making the beam simply supported (i.e., a statically determinate beam). To replace the moment support, a second case consisting of an unknown concentrated moment MB acting clockwise at the right end of the beam is added.