Fixed end

When the end of a beam is free to turn it is referred to as "simply supported"; but if it is restrained so that it cannot rotate the beam is said to have a "fixed end" or a " built-in end".


At the abutments of a simply-supported beam the bending moment is zero, but restraining moments are present at the ends of a fixed-end beam. The fixing of the ends reduces the deflexion that would otherwise occur, as is readily seen from diagrams of bending moment.