Question 2.8.3: Sketch the bending moment and shear force diagrams for the b...
Sketch the bending moment and shear force diagrams for the beam AB shown in Fig. 2.8-11. Determine the general shape of the bent beam.
Taking moments about A
6R_{B}+2\times 3\times 1.5=2\times 3\times 4.5+4\times 8 R_{B}=8.33 kN
from which R_{A}=16-8.33=7.67 kN
Again, following the directions of the applied loads and the reactions, the shear force diagram may be completed, and the bending moment diagram drawn from the fact that the slope of the latter is equal to minus the ordinate hof the shear force diagram (Section 4.18).
An algebraic maximum occurs at C, 2.17 m to the left of B, and has the value of 3.31 kNm.
Throughout the beam the bending moment is wholly negative and, therefore, the curvature is negative also. The beam is supported at A and B, and its bent shape is wholly convex upwards.