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.