Load Diagram and BMD from the Given SFD:

Q: Shear force diagram of simply supported beam is given in the figure below. Calculate the support reactions of beam and draw bending moment diagram of beam.

Sol.: For given SF_D, First we draw load diagram, and then with the help of load diagram we draw the BM_D.

As slope in SF_D is zero. So it indicates that the beam is subjected to point loads. Let R_A and R_B be the support reaction at points A and B and the load R_C, R_D and RE in down direction at points C, D and E respectively.

Here graph of SF_D moves from A-F-G-C-D-H-E-J-K-B Take two points continuously,

Take A-F

Load moves from A to F,

Load intensity at A = R_A  = Last load - first load = 3.5 - 0 = 3.5KN

Now load diagram is given in fig 12.30

Now Calculation for BM_D

Taking moment about any point gives the value of bending moment at that point.
Take left portion of the beam

Draw BM_D with the help of obtained value.